Flood, Trevor A. MD*; Ulbright, Thomas M. MD†; Hirsch, Michelle S. MD, PhD‡
doi : 10.1097/PAS.0000000000001703
October 2021 - Volume 45 - Issue 10 - p 1299-1302
Flood, Trevor A. MD*; Ulbright, Thomas M. MD†; Hirsch, Michelle S. MD, PhD‡
doi : 10.1097/PAS.0000000000001703
October 2021 - Volume 45 - Issue 10 - p 1299-1302
Lau, Hubert D. MD*; Kao, Chia-Sui MD†; Williamson, Sean R. MD‡; Cheng, Liang MD§; Ulbright, Thomas M. MD§; Idrees, Muhammad T. MD§
doi : 10.1097/PAS.0000000000001704
October 2021 - Volume 45 - Issue 10 - p 1303-1313
Sex cord-stromal tumors (SCSTs) account for the second most common category of testicular neoplasms and include several entities that may show overlapping morphologies and present diagnostic challenges. We analyzed a cohort of 120 testicular SCSTs and investigated the diagnostic utility of SRY-box transcription factor 9 (SOX9), forkhead box protein L2 (FOXL2), and steroidogenic factor 1 (SF-1) immunohistochemical stains. The results were compared with the more commonly used SCST markers, inhibin ?, calretinin, and Wilms’ tumor 1 (WT1). SF-1 was overall the most sensitive stain (91%), followed by inhibin ? (70%), calretinin (52%), FOXL2 (50%), SOX9 (47%), and WT1 (37%), but sensitivities varied by tumor type. SOX9 and calretinin were more commonly positive in sex cord elements versus stromal elements (62% vs. 27% and 47% vs. 9%, respectively), whereas FOXL2 was more commonly positive in stromal elements versus sex cord elements (100% vs. 55%) when excluding Leydig cell tumors from the stromal category. Although no individual stain was diagnostically specific, some immunophenotypic patterns were noted that may help in the subclassification of SCSTs. We conclude that SOX9, FOXL2, and SF-1 are useful immunohistochemical stains for confirming sex cord-stromal differentiation in testicular tumors and provide increased sensitivity as well as additional diagnostic information, especially when combined with the more commonly used inhibin ?, calretinin, and WT1 immunostains. Although morphology is paramount for subclassification of SCSTs, knowledge of certain immunohistochemical patterns may be helpful for diagnostically challenging cases.
Arora, Kshitij S. MD*; Anderson, Mark A. MD†; Neyaz, Azfar MD‡; Yilmaz, Osman MD§,?; Pankaj, Amaya MD‡; Ferrone, Cristina R. MD§; Zen, Yoh MD¶; England, Jonathan MD*; Deshpande, Vikram MD‡
doi : 10.1097/PAS.0000000000001767
October 2021 - Volume 45 - Issue 10 - p 1314-1323
Inflammatory pseudotumor is a term used to designate inflammation-rich tumefactive lesions. Following the exclusion of specific entities such as IgG4-related disease and other neoplastic entities previously included in this entity, the majority of hepatic pseudotumors show a prominent fibrohistiocytic inflammatory reaction and have been previously categorized as fibrohistiocytic variant of hepatic pseudotumor (FHVHPT). The goal of this study was to examine the clinical, radiologic, histologic, and etiologic aspects of this entity. After excluding neoplastic diseases, we identified 30 patients with FHVHPT from 3 institutions between 2009 and 2019. We extracted demographic and clinical data, liver function tests as well as culture results and radiologic information. Hematoxylin and eosin–stained slides were reviewed for pattern of inflammation as well as its cellular composition. Immunohistochemistry for IgG4 and IgG was performed in all cases. The mean age of the 30 lesions characterized as FHVHPT was 56 years (range: 23 to 79?y). Nineteen patients showed solitary lesions; 11 were multiple. The mean size of the lesion was 3.8?cm (range: 1 to 7.5?cm). On imaging, a neoplastic process or metastasis was the leading diagnostic consideration (n=15, 50%). The most common symptom was abdominal pain (n=14/30); 8 patients presented with symptoms compatible with an infectious process, including fever. The inflammatory infiltrate was dominated by lymphocytes and plasma cells, and in most cases, a prominent histiocytic infiltrate (22/30). Neutrophils were identified in 12 cases, with microabscess noted in 8. Storiform pattern of fibrosis was seen in 14/30 cases; obliterative phlebitis was not identified. Culture identified a microorganism in 4 of 9 cases evaluated. The mean IgG4 count was 9.3 per HPF (range: 0 to 51) with 9 of the 26 (35%) biopsies showing >10 IgG4 positive plasma cells per HPF. The mean IgG4 to IgG ratio was 8% (range: 8% to 46%). A hepatectomy was performed in 4 cases. On broad spectrum antibiotics (n=14) the lesions either resolved or decreased in size. Eight patients did not receive specific therapy, nevertheless, the lesion(s) resolved spontaneously in 6 cases, remained stable or decreased in size in 2 cases. Notably, none of these patients showed evidence of a hepatic recurrence. FHVHPT, a tumefactive lesion that mimics hepatic neoplasia, is histologically characterized by a fibrohistiocytic infiltrate. In the majority of patients FHVHPT represents the organizing phase of hepatic abscess and can be successfully managed with antibiotic therapy.
Laurent, Camille MD, PhD*,†; Adélaïde, José PhD‡; Guille, Arnaud PhD‡; Tesson, Bruno PhD§; Gat, Elodie MSc§; Evrard, Solene MD, PhD*; Escudié, Frederic MSc*; Syrykh, Charlotte MD*; Canioni, Danielle MD?; Fabiani, Bettina MD¶; Meignin, Véronique MD#; Chassagne-Clement, Catherine MD**; Dartigues, Peggy MD††; Traverse-Glehen, Alexandra MD, PhD‡‡; Parrens, Marie MD§§; Huet, Sarah MD, PhD??; Copie-Bergman, Christiane MD, PhD¶¶; Salles, Gilles MD, PhD##; Birnbaum, Daniel MD, PhD‡; Brousset, Pierre MD, PhD*,†; Morschhauser, Franck MD, PhD***; Xerri, Luc MD, PhD†††; the Lymphoma Study Association (LYSA)
doi : 10.1097/PAS.0000000000001726
October 2021 - Volume 45 - Issue 10 - p 1324-1336
Although follicular lymphoma (FL) is usually graded as FL1-2, FL3A, and FL3B, some borderline cases can be observed and led us to investigate the clinicopathologic diversity of grade 3 FL (FL3). Among 2449 FL patients enrolled in Lymphoma Study Association (LYSA) trials, 1921 cases with sufficient material underwent a central pathologic review. The resulting diagnoses comprised 89.6% FL1-2 (n=1723), 7.2% FL3A (n=138), and 0.5% purely follicular FL3B (n=9). The remaining 51 unclassifiable cases (2.7%) exhibited high-grade features but did not meet WHO criteria for either FL3A or FL3B; and were considered as “unconventional” high-grade FL (FL3U). FL3U morphological pattern consisted of nodular proliferation of large cleaved cells or small-sized to medium-sized blast cells. Compared with FL3A, FL3U exhibited higher MUM1 and Ki67 expression, less BCL2 breaks and more BCL6 rearrangements, together with a higher number of cases without any BCL2, BCL6 or MYC rearrangement. FL3U harbored less frequent mutations in BCL2, KMT2D, KMT2B, and CREBBP than FL3A. MYC and BCL2 were less frequently mutated in FL3U than FL3B. Rituximab cyclophosphamide, doxorubicin, vincristine, and prednisone treated FL3U patients had a worse survival than FL1-2 patients with similar follicular lymphoma international prognostic index and treatment. These results suggest that high-grade FLs encompass a heterogeneous spectrum of tumors with variable morphology and genomic alterations, including FL3U cases that do not strictly fit WHO criteria for either FL3A or FL3B, and display a worse outcome than FL1-2. The distinction of FL3U may be useful to allow a better comprehension of high-grade FLs and to design clinical trials.
Rooper, Lisa M. MD*; Argyris, Prokopios P. DDS, MS, PhD†,‡,§; Thompson, Lester D.R. MD?; Gagan, Jeffrey MD, PhD¶; Westra, William H. MD#; Jordan, Richard C. DDS, PhD**; Koutlas, Ioannis G. DDS, MS§; Bishop, Justin A. MD¶
doi : 10.1097/PAS.0000000000001688
October 2021 - Volume 45 - Issue 10 - p 1337-1347
Mucin-producing salivary adenocarcinomas were historically divided into separate colloid carcinoma, papillary cystadenocarcinoma, and signet ring cell carcinoma diagnoses based on histologic pattern, but have recently been grouped together in the adenocarcinoma not otherwise specified category. It is currently unclear if these tumors represent 1 or more distinct entities and how they are related to well-circumscribed papillary mucinous lesions with recurrent AKT1 E17K mutations that were recently described as salivary intraductal papillary mucinous neoplasm. Here, we sought to evaluate the clinicopathologic and molecular features of salivary mucinous adenocarcinomas to clarify their classification. We identified 17 invasive mucin-producing salivary adenocarcinomas, 10 with a single histologic pattern, and 7 with mixed patterns. While most tumors demonstrated papillary growth (n=15), it was frequently intermixed with colloid (n=6) and signet ring (n=3) architecture with obvious transitions between patterns. All were cytokeratin 7 positive (100%) and cytokeratin 20 negative (0%). Next-generation sequencing performed on a subset demonstrated recurrent AKT1 E17K mutations in 8 cases (100%) and TP53 alterations in 7 cases (88%). Of 12 cases with clinical follow-up (median: 17?mo), 4 developed cervical lymph node metastases, all of which had colloid or signet ring components. Overall, overlapping histologic and immunohistochemical features coupled with recurrent AKT1 E17K mutations across patterns suggests that mucin-producing salivary adenocarcinomas represent a histologically diverse single entity that is closely related to tumors described as salivary intraductal papillary mucinous neoplasm. We propose a unified mucinous adenocarcinoma category subdivided into papillary, colloid, signet ring, and mixed subtypes to facilitate better recognition and classification of these tumors.
Wright, Thomas C. Jr MD*; Stoler, Mark H. MD†; Ferenczy, Alex MD‡; Ranger-Moore, James PhD§; Fang, Qijun PhD§; Kapadia, Monesh MD§; Singh, Shalini MD§; Ridder, Ruediger PhD§
doi : 10.1097/PAS.0000000000001709
October 2021 - Volume 45 - Issue 10 - p 1348-1356
The Lower Anogenital Squamous Terminology (LAST) Project recommends the use of p16 immunohistochemistry as an adjunct to morphologic assessment of cervical biopsies according to a specific set of criteria. We analyzed the effect of adjunctive p16 according to LAST criteria in a US-based diagnostic utility study involving 70 surgical pathologists providing a total of 38,500 reads on cervical biopsies. Compared with the results obtained using hematoxylin and eosin-stained slides only, including p16-stained slides per LAST criteria increased sensitivity and specificity for diagnosing histologic high-grade squamous intraepithelial lesions across all cases by 8.1% (95% confidence interval [95% CI], 6.5-9.7; P<0.0001) and 3.5% (95% CI, 2.8-4.2; P<0.0001), respectively, using expert consensus diagnoses on hematoxylin and eosin+p16 as reference. Within the subset of cases classified by the pathologists as fulfilling the LAST criteria, adding p16 significantly increased both sensitivity (+11.8%; 95% CI, 9.5-14.0; P<0.0001) and specificity (+9.7%; 95% CI, 7.8-11.5; P<0.0001). However, a comparable improvement in sensitivity (+11.0%; 95% CI, 7.8-14.1; P<0.0001) was found when p16 was used in cases for which p16 staining was not ordered per LAST by the pathologists, whereas specificity decreased by ?0.8% (95% CI, ?1.1 to ?0.5; P<0.0001). The study demonstrates a clinically and statistically significant increase in sensitivity and specificity for high-grade squamous intraepithelial lesion when p16 is used according to LAST criteria. Expanding the use of p16 into non-LAST cases would lead to a comparable improvement in sensitivity within this subgroup of biopsies, at the cost of a minimal, but statistically significant difference in specificity.
Krystel-Whittemore, Melissa MD*; Chan, May P. MD†; Shalin, Sara C. MD‡,§; Sauder, Kenan J. MD?; Hudson, Amy MD¶; Foreman, Ruth K. MD, PhD*; Hoang, Mai P. MD*; Brennick, Jeoffry B. MD#,**; Yan, Shaofeng MD#,**; Nazarian, Rosalynn M. MD*
doi : 10.1097/PAS.0000000000001733
October 2021 - Volume 45 - Issue 10 - p 1357-1363
Herpes viruses are known for infecting epithelial cells and manifesting as vesicles. However, herpes viruses can also infect stromal cells. While established in the ocular setting, cutaneous stromal herpes (deep herpes) is previously unreported and may evade clinical and microscopic detection. We searched for skin biopsies with herpes stromal disease. Clinical information was retrieved via electronic medical records and pathology records system. Hematoxylin and eosin slides, immunohistochemical staining, and polymerase chain reaction detection of viral DNA was performed. We identified 12 specimens from 10 patients with cutaneous stromal herpes simplex virus 1/2 (n=7) or varicella-zoster virus infection (n=5). The most common site involved was the buttocks/perianal region (n=6). Ulceration was a frequent dermatologic finding (n=8). Pyoderma gangrenosum was clinically suspected in 6 specimens (50%). Eight patients (80%) were immunosuppressed. Biopsies frequently demonstrated a dense dermal mixed inflammatory infiltrate with subcutaneous extension and enlarged cells with viral cytopathic changes confirmed by herpes simplex virus 1/2 or varicella-zoster virus immunohistochemistry (n=10) or polymerase chain reaction (n=2). Most specimens (67%) lacked evidence of characteristic epidermal keratinocyte infection. This study presents the first known report of the ability of herpes virus to infect deep stromal cells of the dermis. We raise awareness of cutaneous stromal herpes in patients presenting with atypical clinical lesions, particularly while immunocompromised. Establishing the correct diagnosis is critical for initiating therapy.
Dhall, Deepti MD*; Shi, Jiaqi MD, PhD†; Allende, Daniela S. MD‡; Jang, Kee-Taek MD§; Basturk, Olca MD?; Adsay, Volkan MD¶; Kim, Grace E. MD#
doi : 10.1097/PAS.0000000000001723
October 2021 - Volume 45 - Issue 10 - p 1364-1373
In recent literature and international meetings held, it has become clear that there are significant differences regarding the definition of what constitutes as margins and how best to document the pathologic findings in pancreatic ductal adenocarcinoma. To capture the current practice, Pancreatobiliary Pathology Society (PBPS) Grossing Working Group conducted an international multispecialty survey encompassing 25 statements, regarding pathologic examination and reporting of pancreatic ductal adenocarcinoma, particularly in pancreatoduodenectomy specimens. The survey results highlighted several discordances; however, consensus/high concordance was reached for the following: (1) the pancreatic neck margin should be entirely submitted en face, and if tumor on the slide, then it is considered equivalent to R1; (2) uncinate margin should be submitted entirely and perpendicularly sectioned, and tumor distance from the uncinate margin should be reported; (3) all other surfaces (including vascular groove, posterior surface, and anterior surface) should be examined and documented; (4) carcinoma involving separately submitted celiac axis specimen should be staged as pT4. Although no consensus was achieved regarding what constitutes R1 versus R0, most participants agreed that ink on tumor or at and within 1?mm to the tumor is equivalent to R1 only in areas designated as a margin, not surface. In conclusion, this survey raises the awareness of the discordances and serves as a starting point towards further standardization of the pancreatoduodenectomy grossing and reporting protocols.
Zhang, Ruth MD*; Rabinovitch, Peter S. MD, PhD†; Mattis, Aras N. MD, PhD*; Lauwers, Gregory Y. MD‡; Choi, Won-Tak MD, PhD*
doi : 10.1097/PAS.0000000000001764
October 2021 - Volume 45 - Issue 10 - p 1374-1381
Most gastric cancers (GCs) are thought to develop via gastric intestinal metaplasia (GIM)-dysplasia-carcinoma pathway. Patients with extensive and/or incomplete GIM have been reported to have a higher risk of GC. GIM can also display dysplasia-like cytoarchitectural atypia limited to the bases of gastric pits without surface involvement. However, only a small proportion of GIM patients will develop gastric neoplasia, and it remains questionable if GIM is a direct precursor. A cohort of 82 GC patients with GIM who underwent gastrectomy were analyzed. DNA flow cytometry was performed on 109 GIM samples (including 88 predominantly complete GIM and 21 predominantly incomplete GIM subclassified based on morphology) obtained from adjacent mucosa of the 82 GCs. Only 2 (2%) of the 109 GIM samples demonstrated aneuploidy, both from 2 minority patients (Asian and Hispanic) with limited and complete GIM and no cytoarchitectural atypia. The remaining 107 GIM samples showed mild to focally moderate basal gland (metaplastic) atypia limited to the bases of gastric pits, but they all demonstrated normal DNA content regardless of anatomic location, histologic GIM subtype, or varying degrees of basal gland atypia. In conclusion, the vast majority of the GIM samples (98%) lack the aneuploidy that is characteristic of gastric dysplasia or cancer. This indicates that aneuploidy usually occurs after the development of gastric dysplasia rather than at the stage of GIM. The finding also suggests that the presence of GIM alone may not be sufficient to suggest an increased risk for GC and that the inclusion of other high-risk features (ie, extensive GIM, dysplasia, racial minorities, and/or family history of GC in a first-degree relative) and/or aneuploidy ought to play a role in the selection of GIM patients who may warrant endoscopic surveillance. Finally, GIM with mild to focally moderate basal gland atypia is likely to represent metaplastic atypia in most cases.
Monteagudo, Carlos MD, PhD*,†; Fúnez, Rafael MD‡; Sánchez-Sendra, Beatriz BSBC†; González-Muñoz, José F. BBiot*; Nieto, Gema BSB†; Alfaro-Cervelló, Clara MD, PhD*; Murgui, Amelia MD, PhD§; Barr, Ronald J. MD?
doi : 10.1097/PAS.0000000000001727
October 2021 - Volume 45 - Issue 10 - p 1382-1390
The term “cutaneous lymphadenoma” was coined in this journal for an unusual lymphoepithelial cutaneous adnexal neoplasm, possibly with immature pilosebaceous differentiation. Some authors further proposed that cutaneous lymphadenoma was an adamantinoid trichoblastoma. However, although a hair follicle differentiation is widely accepted, the fact that this is a lymphoepithelial tumor is not appropriately explained by the trichoblastoma hypothesis. Our goal was to further clarify the phenotypic and genotypic features of cutaneous lymphadenoma in a series of 11 cases. Histologically, a lobular architecture surrounded by a dense fibrous stroma was present in all cases. The lobules were composed of epithelial cells admixtured with small lymphocytes and isolated or clustered large Reed-Sternberg–like (RS-L) cells. The epithelial cells were diffusely positive for the hair follicle stem cell markers CK15, PHLDA1, and for androgen receptor. No immunostaining for markers of sebaceous differentiation was found. Intraepithelial lymphocytes were predominantly CD3+, CD4+, FoxP3+ T cells. RS-L cells showed both strong Jagged-1 and Notch1 cytoplasmic immunostaining. Androgen-regulated NKX3.1 nuclear immunostaining was present in a subset of large intralobular cells in all cases. Double immunostaining showed coexpression of NKX3.1 and CD30 in a subset of RS-L cells. No immunostaining for lymphocytic or epithelial markers was present in RS-L cells. EGFR, PIK3CA, and FGFR3 somatic mutations were found by next-generation sequencing in 56% of the cases. We consider that cutaneous lymphadenoma is a distinct benign lymphoepithelial tumor with androgen receptor and hair follicle bulge stem cell marker expression, RS-L cell-derived Notch1 ligand, and common EGFR gene mutations.
Katz, Samuel G. MD, PhD; Edappallath, Susmitha MD; Xu, Mina L. MD
doi : 10.1097/PAS.0000000000001765
October 2021 - Volume 45 - Issue 10 - p 1391-1398
Blast evaluation in patients with acute monocytic leukemias (AMoL) is notoriously difficult due to the lack of reliable surface markers and cytologic subtleties on the aspirate smears. While blasts of most nonmonocytic acute leukemias express CD34, available immunohistochemical antibodies to monocytic blasts also mark normal background mature monocytes. We searched for a potential biomarker candidate by surveying specific gene expression profiles of monocyte progenitors. Our investigations led us to IRF8, which is a lineage-specific transcription factor critical for the production of monocytic and dendritic cell progenitors. In this study, we tested and validated a monoclonal antibody to IRF8 as a novel immunohistochemical stain for trephine core biopsies of human bone marrow. We assessed the expression of IRF8 in 90 cases of AMoL, including posttherapy staging bone marrows, 23 cases of chronic myelomonocytic leukemia, 26 cases of other acute myeloid leukemia subtypes, and 18 normal control marrows. In AMoL, there was high correlation of IRF8-positive cells to aspirate blast count (R=0.95). Comparison of IRF8 staining to aspirate blast percentage in chronic myelomonocytic leukemia also showed good correlation (R=0.86). In contrast, IRF8-positive cells did not correlate with blast count in other subtypes of acute myeloid leukemia (R=0.56) and staining was <5% in all normal control marrows, even those with reactive monocytosis. We found that IRF8 was also weakly reactive in B cells and hematogones, with the latter accounting for rare cases of discrepancies. When IRF8 was used to categorize cases as AMoL, positive for residual leukemia or negative, the sensitivity was 98%, specificity was 82%, positive predictive value was 86%, and negative predictive value was 98%. These results demonstrate that IRF8 may serve as a clinically useful immunostain to diagnose and track AMoLs on bone marrow core biopsies. This can be particularly impactful in the setting of poor aspiration and focal blast increase. In the era of new targeted therapies that have been reported to induce monocytic outgrowths of leukemia, a marker for malignant monoblasts may prove even more critical.
Wang, Gang MD, PhD*,†; Yuan, Ren MD, PhD†,‡; Zhou, Chen MD, PhD*,†; Guo, Charles MD, PhD§; Villamil, Carlos MD*,†; Hayes, Malcolm MD*,†; Eigl, Bernhard J. MD†,?; Black, Peter MD†,¶
doi : 10.1097/PAS.0000000000001740
October 2021 - Volume 45 - Issue 10 - p 1399-1408
Large cell neuroendocrine carcinoma (LCNEC) of the urinary tract is a rare disease. We present a relatively large retrospective cohort of urinary LCNEC, 20 from the urinary bladder, and 2 from the ureter, from a single institution. The patients included 16 men and 6 women with a median age of 74.5 years. Most LCNEC presented at an advanced stage with tumors invading the muscularis propria and beyond (21/22). Eight cases were pure LCNEC, while 14 cases were mixed with other histologic types, including conventional urothelial carcinoma (n=9), carcinoma in situ (n=7), small cell carcinoma (n=6), and urothelial carcinoma with glandular (n=3) features. Most LCNEC expressed neuroendocrine markers synaptophysin (22/22), chromogranin (13/16), CD56 (7/7), TTF1 (8/8), and INSM1 (2/3). They were negative for common urothelial markers including HMWCK (0/3), p40/p63 (0/6), CK20 (0/10), and had variable GATA3 staining (4/8). Ki-67 stained 25% to nearly 100% tumor cell nuclei. Patient survival was associated with cancer stage, and pure LCNEC showed worse survival than mixed LCNEC. Compared with small cell carcinoma at similar stages from a prior study, LCNEC had a worse prognosis only when patients developed metastatic disease. For organ-confined LCNEC, neoadjuvant chemotherapy followed by radical resection is the treatment option to achieve long-term survival.
Tsai, Jia-Huei MD, PhD*,†; Liau, Jau-Yu MD, PhD*,†; Lee, Chia-Hsiang MSc*; Jeng, Yung-Ming MD, PhD*,†
doi : 10.1097/PAS.0000000000001716
October 2021 - Volume 45 - Issue 10 - p 1409-1418
The molecular characteristics of lymphoepithelioma-like intrahepatic cholangiocarcinoma (LELCC) remain elusive. We examined 27 LELCC cases through next-generation sequencing using a panel of genes commonly mutated in primary liver cancers. Alterations in BAP1, ARID1A, ARID2, and PBRM1 were detected through immunohistochemistry. Fluorescence in situ hybridization was performed to analyze FGFR2 fusions and CCND1 amplification. LELCC is histologically classified as predominantly undifferentiated or glandular. Epstein-Barr virus–encoded small RNA (EBER) expression was found in 16 LELCCs. Approximately 50% of LELCCs expressed programmed death-ligand 1 strongly. Notably, recurrent pTERT and TP53 mutations were detected in 9 (38%) and 8 (33%) tumors, respectively. Only 2 LELCCs exhibited loss of expression for PBRM1. Alterations in genes typically involved in intrahepatic cholangiocarcinoma, including IDH1, IDH2, ARID1A, ARID2, and BAP1, and FGFR2 fusions, were not identified. The 2-step clustering analysis showed 2 distinct subgroups in LELCC, which were separated by EBER expression. A meta-analysis of all reported cases (n=85) has shown that EBER+ LELCC is strongly associated with the female sex, younger age, and exhibited predominantly glandular differentiation (P=0.001, 0.012, and <0.001, respectively). Patients with EBER? LELCC were more likely to have viral hepatitis and cirrhosis (P=0.003 and 0.005, respectively). Genetic analysis demonstrated that EBER? LELCC was significantly associated with pTERT and TP53 mutations (P=0.033 and 0.008, respectively). In conclusion, LELCC is genetically distinct from intrahepatic cholangiocarcinoma. EBER? LELCC may exhibit a different pathogenesis from EBER+ LELCC. High programmed death-ligand 1 expression in LELCC has implications for potential immunotherapeutic strategies.
Shivji, Sameer MD*,†; Kak, Ipshita MD*,†; Reid, Stephanie L. MD*,†; Muir, Jennifer MD*,†; Hafezi-Bakhtiari, Sara MD†,‡; Li-Chang, Hector MD§; Deliallisi, Ardit MD?; Newell, Ken J. MD?; Grin, Andrea MD¶; Conner, James MD*,†; Kirsch, Richard MBChB*,†
doi : 10.1097/PAS.0000000000001707
October 2021 - Volume 45 - Issue 10 - p 1419-1427
Venous invasion (VI) is a powerful prognostic factor in colorectal cancer (CRC) that is widely underreported. The ability of elastin stains to improve VI detection is now recognized in several international CRC pathology protocols. However, concerns related to the cost and time required to perform and evaluate these stains in addition to routine hematoxylin and eosin (H&E) stains remains a barrier to their wider use. We therefore sought to determine whether an elastin trichrome (ET) stain could be used as a “stand-alone” stain in CRC resections, by comparing the sensitivity, accuracy, and reproducibility of detection of CAP-mandated prognostic factors using ET and H&E stains. Representative H&E- and ET-stained slides from 50 CRC resections, including a representative mix of stages and prognostic factors, were used to generate 2 study sets. Each case was represented by H&E slides in 1 study set and by corresponding ET slides from the same blocks in the other study set. Ten observers (3 academic gastrointestinal [GI] pathologists, 4 community pathologists, 3 fellows) evaluated each study set for CAP-mandated prognostic factors. ET outperformed H&E in the assessment of VI with respect to detection rates (50% vs. 28.6%; P<0.0001), accuracy (82% vs. 59%, P<0.0001), and reproducibility (k=0.554 vs. 0.394). No significant differences between ET and H&E were observed for other features evaluated. In a poststudy survey, most observers considered the ease and speed of assessment at least equivalent for ET and H&E for most prognostic factors, and felt that ET would be feasible as a stand-alone stain in practice. If validated by others, our findings support the use of ET, rather than H&E, as the primary stain for the evaluation of CRC resections.
Lorenzi, Luisa MD, PhD*,†; Lonardi, Silvia BS*,†; Vairo, Donatella PhD‡; Bernardelli, Andrea MD*; Tomaselli, Michela ThS†; Bugatti, Mattia BS*,†; Licini, Sara ThS†; Arisi, Mariachiara MD§; Cerroni, Lorenzo MD?; Tucci, Alessandra MD¶; Vermi, William MD, PhD*,†,#; Giliani, Silvia Clara PhD‡; Facchetti, Fabio MD, PhD*,†
doi : 10.1097/PAS.0000000000001747
October 2021 - Volume 45 - Issue 10 - p 1428-1438
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive neoplasm derived from plasmacytoid dendritic cells (pDCs). In this study, we investigated by immunohistochemical analysis the expression of E-cadherin (EC) on pDCs in reactive lymph nodes and tonsils, bone marrow, and in BPDCN. We compared the expression of EC in BPDCN to that in leukemia cutis (LC) and cutaneous lupus erythematosus (CLE), the latter typically featuring pDC activation. In BPDCN, we also assessed the immunomodulatory activity of malignant pDCs through the expression of several type I interferon (IFN-I) signaling effectors and downstream targets, PD-L1/CD274, and determined the extent of tumor infiltration by CD8-expressing T cells. In reactive lymph nodes and tonsils, pDCs expressed EC, whereas no reactivity was observed in bone marrow pDCs. BPDCN showed EC expression in the malignant pDCs in the vast majority of cutaneous (31/33 cases, 94%), nodal, and spleen localizations (3/3 cases, 100%), whereas it was more variable in the bone marrow (5/13, 38,5%), where tumor cells expressed EC similarly to the skin counterpart in 4 cases and differently in other 4. Notably, EC was undetectable in LC (n=30) and in juxta-epidermal pDCs in CLE (n=31). Contrary to CLE showing robust expression of IFN-I-induced proteins MX1 and ISG5 in 20/23 cases (87%), and STAT1 phosphorylation, BPDCN biopsies showed inconsistent levels of these proteins in most cases (85%). Expression of IFN-I-induced genes, IFI27, IFIT1, ISG15, RSAD2, and SIGLEC1, was also significantly (P<0.05) lower in BPDCN as compared with CLE. In BPDCN, a significantly blunted IFN-I response correlated with a poor CD8+T-cell infiltration and the lack of PD-L1/CD274 expression by the tumor cells. This study identifies EC as a novel pDC marker of diagnostic relevance in BPDCN. The results propose a scenario whereby malignant pDCs through EC-driven signaling promote the blunting of IFN-I signaling and, thereby, the establishment of a poorly immunogenic tumor microenvironment.
Blaauwgeers, Hans MD*; Thunnissen, Erik PhD, MD†
doi : 10.1097/PAS.0000000000001787
October 2021 - Volume 45 - Issue 10 - p 1439
Metovic, Jasna MD*; Volante, Marco MD, PhD†; Righi, Luisella MD, PhD†; Papotti, Mauro MD*
doi : 10.1097/PAS.0000000000001791
October 2021 - Volume 45 - Issue 10 - p 1439-1440
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