American Journal of Surgical Pathology最新文献

Oncocytic adenocarcinoma (OC) of the salivary glands is a rare and controversial entity. It was recently reclassified as "salivary carcinoma NOS and emerging entities" in the 2022 WHO classification of head and neck tumors. The lack of specific molecular alterations and its potential affiliation with other salivary gland carcinomas, such as the oncocytic mucoepidermoid carcinomas (OMEC) or the oncocytic subtype of salivary duct carcinomas (OSDC) justified this reclassification. It is becoming essential to clarify the complex spectrum of potential diagnoses surrounding oncocytic tumors. The objective of this study was to explore the histologic features, as well as the immunohistochemical and molecular profiles, of cases previously diagnosed as OC or OMEC of the salivary glands. This study involved 28 cases of carcinomas with a predominantly oncocytic component. The sex distribution was equal. The median age was 59 years (range 10 to 89). Most of these cases originated from the parotid gland (25/28). The mean tumor size was 2.4 cm (range 0.5 to 6.5). Primary immuno-morphological and mutation/gene fusion profiles reclassified mainly (64.3%, 18/28). Most of them were reclassified in descending order as OSDC (8/18), OMEC (5/18), and OC (2/18). But 3 cases remained unclassified (3/18). The transcriptomic analysis found a proximity of their transcriptomic profile with the OMEC group and a distance from the OSDCs. These findings imply that OC is not distinct but represents oncocytic variants of other salivary carcinomas. It underscores the importance of thorough morphologic, immunohistochemical, and molecular examinations to accurately diagnose carcinomas with predominant oncocytic components in the salivary glands.

Ovarian serous borderline tumors (SBTs) have a generally favorable prognosis. Although the risk of progression to low-grade serous carcinoma is well documented, progression to high-grade carcinoma is rare. We report the clinicopathologic features of seven SBTs, each associated with the presence of a morphologically unique high-grade component with an extremely dismal prognosis. All of the SBTs exhibited typical hierarchical branching and scattered eosinophilic cells, whereas the high-grade component consisted of a profuse proliferation of epithelioid cells with abundant dense, eosinophilic cytoplasm, variable nuclear pleomorphism, and evident loss of WT1, estrogen receptor, and p16 positivity. In most cases, the SBT demonstrated an abrupt transition to the high-grade component, but one patient initially presented with the usual SBT and developed a recurrent disease that was composed entirely of the high-grade component. Targeted next-generation sequencing revealed identical driver mutations in both the SBT and high-grade components ( BRAF in 3, KRAS in 1), confirming clonality. Three cases, in addition, harbored telomerase reverse transcriptase promoter mutations in both components. One case, despite insufficient material for sequencing, was BRAF V600E-positive by immunohistochemistry. Most patients with available follow-up data died within 9 months of diagnosis. This study confirms prior reports of ovarian SBT transformation to high-grade carcinoma and further characterizes a distinct subset with abundant dense eosinophilic cytoplasm and an extremely dismal prognosis. The presence of BRAF mutations in a major subset of these tumors questions the notion that BRAF is associated with senescent eosinophilic cells and improved outcomes in SBT. The role of the additional telomerase reverse transcriptase promoter mutations merits further investigation.

Burkitt lymphoma is characterized by high cell turnover and numerous cytoplasmic vacuoles that are demonstrated to be lipid droplets (LDs) decorated by adipophilin. By contrast, cytoplasmic vacuoles are variably observed in diffuse large B-cell lymphoma (DLBCL) and less well characterized. In this study, we first validated in DLBCL that cytoplasmic vacuoles are indeed LDs by Oil-red-O stain, Bodipy fluorescent stain, and electron microscopy. Second, in a cohort of DLBCL patients (n=52) we showed that LDs in effusional lymphoma cells were associated with a poorer prognosis ( P =0.029, log-rank test) and higher International Prognostic Index (IPI) score (94% vs. 66%, P =0.026) than those without. Moreover, using adipophilin as a surrogate marker for LDs, we found in another cohort of biopsy specimen (n=85) that expression of adipophilin by lymphoma cells predicted a poorer prognosis ( P =0.007, log-rank test) and higher IPI score (63% vs. 30%, P =0.005). In addition, whole exome sequencing of effusional DLBCL cells showed LD-positive DLBCL shared genetic features with the MCD ( MYD88 and CD79B mutations) subtype and highlighted OSBPL10 and CUBN as the most frequently mutated genes involved in lipogenesis. Whole transcriptome analysis by comparing effusional DLBCL cells with versus without LDs showed upregulation of EHHADH , SLC1A1 , CD96 , INPP4B , and RNF183 relevant for lymphoma lipogenesis and upregulation of epithelial-mesenchymal transition and KRAS signaling pathways. Higher expression of EHHADH and CD96 were validated in LD-positive clinical samples and LD-rich cell lines than LD-poor cells along with the known lipogenic gene, FASN . Our findings highlight the roles of LDs and adipophilin expression in DLBCL, suggest that these markers may predict prognosis and show that lipogenic genes may be potential therapeutic targets.

Astroblastoma is an extremely rare central nervous system tumor characterized by astroblastic pseudorosettes and vascular hyalinization. Despite these histologic hallmarks, its morphology can vary, occasionally resembling other central nervous system tumors such as ependymoma. A novel tumor entity, astroblastoma, meningioma 1 ( MN1 )-altered, has been identified, featuring MN1 gene rearrangements typically involving BEN-domain containing 2 ( BEND2 ) as a fusion partner. Most astroblastomas arise in the cerebral hemisphere. Here, we report 4 cases of spinal cord astroblastoma in female patients, all showing Ewing sarcoma RNA-binding protein 1 fusion with BEND2 , rather than MN1 . These tumors displayed growth patterns akin to traditional intracranial astroblastomas, with three cases demonstrating high-grade histology, including elevated mitotic activity and necrosis. Interestingly, some cases exhibited positive staining for pan-cytokeratin and hormone receptors. DNA methylation profiling clustered three of the four cases with the reference "AB_EWSR," whereas one case exhibited an independent methylation signature near the reference methylation group "AB_EWSR" and "pleomorphic xanthoastrocytoma." Together with the existing literature, we summarized a total of eleven cases, which predominantly affected children and young adults with female predilection. Eight of 10 patients experienced recurrence, underscoring the aggressive nature of this disease. We suggest recognizing a new molecular subgroup of spinal astroblastoma and recommend testing newly diagnosed infratentorial astroblastomas for Ewing sarcoma RNA-binding protein 1-BEND2 fusion.

Multiple endocrine neoplasms are a feature of multiple endocrine neoplasia (MEN) syndromes types 1, 2, 4, and 5. However, the ileum is not usually involved in these disorders. We report a series of patients with neuroendocrine tumors (NETs) involving both the pancreas and the ileum. We searched the laboratory information system and personal consultation records of the authors from 2019 to 2023 for patients who had neuroendocrine tumors (NETs) involving both the pancreas and ileum. In a series of 846 patients, we identified 4 patients with pancreatic and ileal NETs, 2 female and 2 male, ages 52 to 75. Two female patients had primary EC cell tumors of the ileum with metastasis to the pancreas that showed expression of CDX2 and serotonin similar to the ileal primary tumors. Two males had primary lesions in the 2 sites with different immunoprofiles; the ileal tumors expressed CDX2 and serotonin and were negative for ARX, whereas the pancreatic tumors expressed ARX, glucagon, and pancreatic polypeptide and were negative for CDX2 and serotonin. In both male patients, the nontumorous pancreas showed preneoplastic changes in the endocrine elements, suggesting germline predisposition to endocrine neoplasia. Testing for known genetic alterations underlying MEN syndromes has not identified a genetic alteration that can be implicated in the development of NETs in both pancreas and ileum. Our series indicates the rare occurrence of NETs in both the pancreas and ileum and emphasizes the importance of using the correct biomarkers to distinguish metastasis from primary neoplasms at the different sites. The rare occurrence of primary ileal and pancreatic NETs may represent a novel MEN syndrome with as yet unknown germline predisposition.

Penile squamous cell carcinoma (PSCC) is classified into 2 prognostically distinct types: human papillomavirus (HPV)-associated and HPV-independent. However, the impact of p53 status on prognosis remains controversial. We correlated HPV and p53 status with the prognosis of a large series of patients with PSCC. p53 was analyzed according to a recently described immunohistochemical (IHC) pattern-based framework that includes 2 normal and 4 abnormal patterns and closely correlates with TP53 mutational status. A total of 122 patients with surgically treated PSCC in 3 hospitals were included. Based on HPV in situ hybridization and p16 and p53 IHC, the tumors were classified into 3 subtypes: HPV-associated, HPV-independent/p53 normal, and HPV-independent/p53 abnormal. All patients were followed up for at least 22 months (median: 56.9 months). Thirty-six tumors (29%) were HPV-associated, 35 (29%) were HPV-independent/p53 normal, and 51 (42%) were HPV-independent/p53 abnormal. Disease-related deaths were observed in 3/36 (8%), 0/35 (0%) and 14/51 (27%) of the patients, respectively ( P < 0.001). A total of 7/14 deaths in the latter group were patients with tumors showing p53 abnormal patterns not recognized in the classic p53 IHC interpretation (basal, null, and cytoplasmic). According to our multivariate analysis, HPV-independent/p53 abnormal tumors and advanced stage were associated with impaired disease-specific survival (hazard ratio = 23.4, 95% CI = 2.7-3095.3; P = 0.001 and 16.3, 95% CI = 1.8-2151.5; P = 0.008, respectively). In conclusion, compared with patients with HPV-associated and HPV-independent/p53-normal PSCC, patients with HPV-independent/p53 abnormal PSCC have worse clinical outcomes. p53 IHC results define 2 prognostic categories in HPV-independent PSCC: HPV-independent/p53-normal tumors as low-risk tumors, whereas HPV-independent/p53-abnormal tumors as aggressive neoplasms.

Aims: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

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.