Dorukhan Bahceci, Grace E Kim, Sanjay Kakar, Dana J Balitzer, Eric D Nguyen, Rageshree Ramachandran, Sarah E Umetsu, Nancy M Joseph
{"title":"Expanding the Spectrum of GLI1-rearranged Neoplasms of the Gastrointestinal Tract to Include Monophasic Keratin-positive Epithelial Neoplasms.","authors":"Dorukhan Bahceci, Grace E Kim, Sanjay Kakar, Dana J Balitzer, Eric D Nguyen, Rageshree Ramachandran, Sarah E Umetsu, Nancy M Joseph","doi":"10.1097/PAS.0000000000002303","DOIUrl":"10.1097/PAS.0000000000002303","url":null,"abstract":"<p><p>GLI1-altered tumors form a diverse group occurring in various anatomic locations. In the alimentary tract, the most established are gastroblastoma, a biphasic epithelial-mesenchymal neoplasm of the stomach, and plexiform fibromyxoma, a pure spindle cell neoplasm. The spectrum of GLI1-rearranged gastrointestinal tumors has recently expanded with reports of cases in other parts of the GI tract, some exhibiting gastroblastoma-like features and others being pure mesenchymal neoplasms. These tumors often display a nonspecific immunophenotype, with only CD56 and cyclin D1 expression being common. Biphasic GLI1-altered tumors show diffuse keratin positivity in the epithelial component only, and GLI1-altered mesenchymal tumors typically lack or show only focal keratin expression. This study details 2 GLI1-rearranged gastrointestinal tract tumors with diffuse keratin and CD56 expression, composed entirely of epithelial cells with a nested growth pattern and finely stippled monotonous nuclei, leading to an initial suspicion of neuroendocrine tumor in both cases, despite lack of synaptophysin and chromogranin expression. Diffuse strong nuclear cyclin D1 expression was seen in both cases, and conversely, strong cyclin D1 staining was only seen in 5.4% (4/74) of well-differentiated neuroendocrine tumors tested. These 2 GI tract neoplasms highlight a widened spectrum of GLI1-rearranged tumors, now including monophasic epithelial neoplasms with diffuse keratin expression.</p>","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":"48 11","pages":"1389-1394"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142493120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abbas Agaimy, Robert Stoehr, Cyril Fisher, John S A Chrisinger, Elizabeth G Demicco, Lars Tögel, Michal Michal, Michael Michal
{"title":"ALK -rearranged Mesenchymal Neoplasms With Prominent Foamy/Pseudolipogenic Cell Morphology : Expanding the Phenotypic Spectrum of ALK Fusion Neoplasms and Report of Novel Fusion Partners.","authors":"Abbas Agaimy, Robert Stoehr, Cyril Fisher, John S A Chrisinger, Elizabeth G Demicco, Lars Tögel, Michal Michal, Michael Michal","doi":"10.1097/PAS.0000000000002283","DOIUrl":"10.1097/PAS.0000000000002283","url":null,"abstract":"<p><p>The category of ALK -rearranged mesenchymal neoplasms has been evolving rapidly, with reports of morphologically diverse lesions of cutaneous, soft tissue, and visceral origin. While some of these represent morphologically defined entities harboring recurrent ALK fusions (inflammatory myofibroblastic tumor and epithelioid fibrous histiocytoma), others are unclassified by morphology with variable overlap with the tyrosine kinase family of neoplasia and their underlying ALK fusions cannot be suspected based on morphology. We herein report 3 cases that expand the anatomic, morphologic, and genotypic spectrum of ALK -rearranged unclassified neoplasms. Patients were all adults aged 46 to 69 (median: 63) who presented with a mass located in the gingiva, subcutis of the back, and submucosal posterior pharyngeal wall. The tumor size ranged from 1 to 2.7 cm (median: 1.6). Conservative surgery was the treatment in all patients. Follow-up was available for one patient who remained disease-free at 14 months. Histologically, all tumors displayed large polygonal cells with foamy to granular and lipogenic-like microvacuolated copious cytoplasm and medium-sized round nuclei with 1 or 2 prominent nucleoli. Mitoses and necrosis were not seen. The initial diagnostic impression was PEComa, inflammatory rhabdomyoblastic tumor and unclassified pseudolipogenic neoplasm. Strong cytoplasmic ALK was detected by immunohistochemistry in all cases. Other positive markers include Cathepsin K (2/2), desmin (1/3), focal MyoD1 (1/1), focal SMA (1/3), and focal EMA (1/2). Targeted RNA sequencing revealed ALK fusions with exon 20 (2 cases) and exon 19 (one case) of ALK fused to RND3 (exon 3), SQSTM1 (exon 6), and desmin (intron 6). Methylation profiling in the desmin-fused case (initially diagnosed as inflammatory rhabdomyoblastic tumor) revealed an inflammatory myofibroblastic tumor match with a low confidence score of 0.5 and a flat copy number variation (CNV) profile. No NF1 mutation was detected in this case, altogether excluding an inflammatory rhabdomyoblastic tumor. Our study highlights and expands the morphologic and anatomic diversity of ALK- fused neoplasms and documents novel fusion partners ( RND3 and desmin).</p>","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":" ","pages":"1455-1463"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Papillary Intralymphatic Angioendothelioma Versus Splenic Lymphatic Malformation With Papillary Endothelial Proliferation: Different Terms for the Same Entity.","authors":"Jonathan C Slack, Antonio R Perez-Atayde","doi":"10.1097/PAS.0000000000002309","DOIUrl":"10.1097/PAS.0000000000002309","url":null,"abstract":"","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":" ","pages":"1473-1475"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142279300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pragi Patel, Alice Chen, Natasha Sharma, Yongzhan Zhang, Victor L Quan, Shantel Olivares, Pedram Gerami
{"title":"PRKC Fusion Melanocytic Tumors, a Subgroup of Melanocytic Tumors More Closely Aligned to Blue Nevi Than to PRKAR1A-inactivated Pigmented Epithelioid Melanocytomas.","authors":"Pragi Patel, Alice Chen, Natasha Sharma, Yongzhan Zhang, Victor L Quan, Shantel Olivares, Pedram Gerami","doi":"10.1097/PAS.0000000000002262","DOIUrl":"10.1097/PAS.0000000000002262","url":null,"abstract":"<p><p>Tumors morphologically classified as pigmented epithelioid melanocytomas (PEMs) are genomically diverse, with the 2 most common genomic subtypes being PRKC fusions or PRKAR1A inactivating mutations. PRKC fusions activate the Gα q/11 pathway similar to blue nevi. Conversely, inactivating mutations in PRKAR1A activate the Gα s pathway. We hypothesize that PRKC fusions have greater genomic overlap with blue nevi compared with PRKAR1A-inactivated PEMs. We characterized the clinical and morphologic features of 21 PRKC and PRKACB fusion melanocytic tumors and compared this to PRKAR1A mutated PEMs. To test our hypothesis regarding greater genomic overlap between PRKC fusions and blue nevi relative to PRKAR1A mutated PEMs, we performed a principal component analysis (PCA) using mRNA expression data. Lastly, we performed a meta-analysis focusing on the outcome data of PRKC fusions. PRKC fusions occur at a younger median age than PRKAR1A mutated PEMs (16 vs. 27). Histologically, PRKC fusions have solid aggregates of epithelioid melanocytes not typical of PRKAR1A mutated PEMs. The PCA plot showed no overlap between the PRKC fusion group and the PRKAR1A-mutated PEMs. There was a significant overlap between PRKC fusions and blue nevi. A meta-analysis of PRKC fusion cases in the literature suggests melanoma is uncommon, but the loss of BAP-1 nuclear expression may be associated with an adverse prognosis as in tumors from the blue nevus family. PRKC fusion melanocytic tumors have greater genomic overlap with blue nevi compared with PRKAR1A mutated PEMs. We recommend categorizing benign PRKC fusion melanocytic tumors as blue fusion nevi/tumors.</p>","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":" ","pages":"1349-1358"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141305234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sinonasal Squamous Cell Carcinoma with DEK::AFF2 Rearrangement : An Aggressive Cancer with Bland Morphology.","authors":"Aude Trinquet, Marick Laé, Charles Lépine, Marie-Delphine Lanic, Vanessa Lacheretz-Szablewski, Caroline Shaar Chneker, Jean-Michel Goujon, Valentin Favier, Valérie Costes-Martineau","doi":"10.1097/PAS.0000000000002281","DOIUrl":"10.1097/PAS.0000000000002281","url":null,"abstract":"<p><strong>Aims: </strong>DEK::AFF2 squamous cell carcinoma is a recently described cancer entity, with 29 cases reported to date. Occasionally, these carcinomas appear deceptively indistinguishable; however, specific morphological and phenotypic features suggest the presence of this rearrangement. However, the prognostic value of this diagnosis remains unclear. We aimed to report a new case series with histological, molecular, and clinical features.</p><p><strong>Methods: </strong>We collected data from 15 patients and investigated their phenotypes, including the expression profiles of CK7, P63/P40, PDL1, AFF2, and P16, morphological features, and associated prognostic data. We analyzed these data along with the previously published data.</p><p><strong>Results: </strong>Most of these cases exhibited indicative morphological features, such as exophytic and endophytic papillary growth, nuclear monomorphism, and abundant neutrophil-rich inflammatory infiltrates. Immunohistochemical analysis revealed the expression of AFF2 and squamous cell markers in all the patients. Overexpression of P16 was not detected, whereas CK7 and PDL1 were expressed variably. In our study cohort, a 50% progression or recurrence rate, 25% lymph node metastasis, 17% distant metastasis, and 18% disease-related death were identified, with a short follow-up time.</p><p><strong>Conclusion: </strong>DEK::AFF2 squamous cell carcinoma incidence is probably underestimated. The low-grade appearance of these tumors sometimes limits their detection. The rates of recurrence and metastasis seem to be high despite an often bland morphology. We propose AFF2 immunohistochemistry as an effective tool, and a diagnostic algorithm has been established to support accurate diagnosis of these tumors.</p>","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":" ","pages":"1408-1416"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141915915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Papillary Intralymphatic Angioendothelioma Versus Splenic Lymphatic Malformation With Papillary Endothelial Proliferation: Different Terms for the Same Entity.","authors":"Larisa Debelenko, Fabrizio Remotti","doi":"10.1097/PAS.0000000000002212","DOIUrl":"10.1097/PAS.0000000000002212","url":null,"abstract":"","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":" ","pages":"1472-1473"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140142594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Biomarker Testing in Microinvasive Carcinoma of the Breast.","authors":"Olivier Michaud, Muhammad Ahmad, Syed A Hoda","doi":"10.1097/PAS.0000000000002252","DOIUrl":"10.1097/PAS.0000000000002252","url":null,"abstract":"","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":" ","pages":"1475-1479"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141159915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
John Hanna, Eleanor Russell-Goldman, Esther Baranov, Daniel Pissaloux, Yvonne Y Li, Franck Tirode, Arnaud de la Fouchardiere, Christopher D M Fletcher
{"title":"PEComa With MITF Overexpression: Clinicopathologic and Molecular Analysis of a Series of 36 Cases.","authors":"John Hanna, Eleanor Russell-Goldman, Esther Baranov, Daniel Pissaloux, Yvonne Y Li, Franck Tirode, Arnaud de la Fouchardiere, Christopher D M Fletcher","doi":"10.1097/PAS.0000000000002276","DOIUrl":"10.1097/PAS.0000000000002276","url":null,"abstract":"<p><p>Perivascular epithelioid cell neoplasms (PEComas) are tumors of uncertain cell lineage that occur across a wide age range, at a variety of anatomic sites, and with a female predominance. Most PEComas are associated with dysregulation of the mTOR pathway, most commonly through inactivating mutations of TSC2 or TSC1 . However, a small subset of PEComas are instead associated with TFE3 gene fusions. MITF is closely related to TFE3 and is frequently overexpressed in PEComas, often in a mutually exclusive manner with TFE3. Here we report the clinical, histopathologic, and molecular features of MITF-overexpressing PEComas in a series of 36 cases. The clinical and morphologic features were comparable to conventional PEComa, although the immunohistochemical profile was notable for the relatively limited expression of melanocytic markers, a surprising finding given that MITF is the master regulator of melanocytic differentiation. At the molecular level, 20 cases (56%) showed supernumerary copies of the MITF gene, suggesting a potential explanation for MITF overexpression. A putative genetic driver event within the mTOR pathway was identified in 11 of 15 cases (73%) analyzed by DNA or RNA sequencing. Interestingly, the malignant PEComas showed 2 distinguishing molecular features: they were associated with a complex chromosomal copy number profile, and they tended to show additional genetic changes, most commonly inactivating events involving TP53 , RB1 , and ATRX . These results elucidate key features of PEComas showing MITF overexpression, begin to explain the molecular basis for MITF overexpression in some PEComas and identify potential molecular correlates for malignancy that may be applicable to the broader PEComa family.</p>","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":" ","pages":"1381-1388"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141454687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Intraductal Implantation of Biliary Neoplasms: A Potential Cause of \"Multifocal\" Tumors.","authors":"Yoh Zen, Masayuki Akita, Evangelia Florou, Takumi Fukumoto, Tomoo Itoh, Evangelos Prassas, Krishna Menon, Parthi Srinivasan","doi":"10.1097/PAS.0000000000002279","DOIUrl":"10.1097/PAS.0000000000002279","url":null,"abstract":"<p><p>Multiple biliary tumors rarely develop in patients without underlying chronic hepatobiliary disease. Those lesions are regarded as multifocal neoplasms if there is no interconnecting dysplasia. This study aimed to determine whether 2 separate tumors in the biliary tract represent true multifocal independent tumorigenesis or intraluminal implantation of a single neoplasm. Two separate biliary tumors without intervening dysplasia were identified in 9 cases: biliary intraductal papillary neoplasm (IPNB; n=5) and extrahepatic cholangiocarcinoma (n=4). The 2 tumors were histologically similar in all cases. In 5 metachronous cases, the second tumor developed 2 to 13 years after the complete resection of the first tumor. In 4 synchronous cases, 2 separate neoplasms were identified in a surgical specimen. The metachronous presentation was more common in IPNB cases, whereas the synchronous development was more frequent in cholangiocarcinoma cases. The second tumors in 4 metachronous cases (4/5; 80%) and smaller lesions in all synchronous cases (4/4; 100%) were located in a lower part of the biliary. Immunophenotypes of cytokeratins and mucin core proteins were almost identical between the 2 lesions. Next-generation sequencing also confirmed that the 2 neoplasms shared gene mutations involving KRAS , GNAS , APC , BRAF , CTNNB1 , SMAD4 , TP53 , or ARID1A in all cases. In conclusion, multiple biliary tumors without underlying chronic biliary disease are most likely due to intraductal implantation of a single neoplasm. Thick mucinous bile in IPNB and increasing use of trans-ampullary biliary interventions may contribute to this unique form of tumor extension.</p>","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":" ","pages":"1464-1471"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141465616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jonathan P Rivera, Yi-Chen Yeh, Paul Chih-Hsueh Chen, Jen-Fan Hang
{"title":"Multifocal Papillary Thyroid Carcinomas With Discordant Molecular Drivers: Emphasizing the Morphology and Collision Tumors.","authors":"Jonathan P Rivera, Yi-Chen Yeh, Paul Chih-Hsueh Chen, Jen-Fan Hang","doi":"10.1097/PAS.0000000000002256","DOIUrl":"10.1097/PAS.0000000000002256","url":null,"abstract":"<p><p>Multifocal papillary thyroid carcinomas (PTCs) are common and the majority of the tumors harbor mutual BRAF p.V600E mutation. This study aimed to investigate a contemporary series of multifocal PTCs with discordant molecular drivers. Consecutive thyroidectomies diagnosed with multifocal PTCs ≥0.5 cm between 2019 and 2023 were reviewed. Immunohistochemistry (IHC) for BRAF VE1 was performed for all tumors. Cases with discordant BRAF IHC results or morphologic discrepancy were identified, and BRAF IHC-negative tumors were subjected to RAS Q61R IHC and/or targeted RNA next-generation sequencing. A total of 770 patients with a main PTC ≥0.5 cm were identified; 255 (33.1%) had multifocal disease, and 142 (18.4%) had at least another PTC ≥0.5 cm. Among them, 13 cases (9.2%, 13/142) had discordant molecular drivers. Twelve cases had one or more BRAF -positive PTCs accompanied by a BRAF -negative PTC (3 with CCDC6::RET fusion, 1 with NCOA4::RET fusion, 1 with ACBD5::RET fusion, 2 with ETV6::NTRK3 fusion, 1 with TG::FGFR1 fusion, 1 with LMTK2::BRAF fusion, 1 with AGK::BRAF fusion and RAS p.Q61R mutation, 1 with RAS p.Q61R mutation, and 1 without detectable molecular drivers). The last case had tumors with discordant fusion drivers ( VIM::NTRK3 and TNS1::BRAF ). Most cases showed tumors that were morphologically distinct (92.3%, 12/13) and occurred in the contralateral lobes (76.9%, 10/13). Notably, we identified 4 cases (30.8%) that presented as collision tumors and 6 cases (46.2%) that showed lymph node metastases, including 2 with simultaneous involvement by tumors with discordant molecular drivers, as novel findings. In summary, a subset (9.2%) of multifocal PTCs had discordant molecular drivers and 84.6% of them were a combination of BRAF -positive and kinase gene fusion-associated PTCs, most with distinct morphologies. Almost half of the cases had nodal metastasis and a third of them showed simultaneous involvement by tumors with discordant molecular drivers. The results highlight the clinical importance of identifying such cases, given the potentially different treatments.</p>","PeriodicalId":7772,"journal":{"name":"American Journal of Surgical Pathology","volume":" ","pages":"1359-1371"},"PeriodicalIF":4.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141178906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}