American Journal of Surgical Pathology

Plurihormonal pituitary adenomas/neuroendocrine tumors express multiple pituitary hormones and/or transcription factors, as determined by immunohistochemistry (IHC). Three types exist based on Endocrine WHO 2022 classification: mature plurihormonal PIT1 (pituitary-specific POU-class homeodomain factor-1), immature PIT1-lineage tumors, and a third type with unusual combinations of pituitary hormones and/or transcription factors. However, since then, "somatogonatotroph"/"multilineage" tumors with PIT1/SF1 (steroidogenic factor 1) co-expression have been described, possibly confounding this classification...

Adenoid cystic carcinoma (AdCC) is one of the most common salivary gland malignancies and occurs in all major and minor salivary gland and seromucous gland sites. AdCCs of salivary gland origin have long been categorized as fusion-defined carcinomas owing to the almost consistent presence of fusion genes MYB::NFIB, or less commonly MYBL1::NFIB. We collected a cohort of 95 cases of AdCC, which were largely characterized by canonical fusions MYB::NFIB (49 cases) or MYBL1::NFIB (9 cases). In additional 11 cases of AdCC, rearrangements in MYB or NFIB genes were detected by FISH...

Birt-Hogg-Dubé (BHD) syndrome is a rare inherited disease characterized by a variety of renal epithelial tumors and oncocytosis, with extrarenal manifestations primarily consisting of pulmonary cysts and cutaneous fibrofolliculomas. Here we report a unique case of a primary extrarenal BHD-associated oncocytic epithelial neoplasm which arose between the duodenum and head of the pancreas. The unusual morphology and immunoprofile of this lesion defied classification as any previously reported entity, despite an extensive diagnostic workup...

Embryonal rhabdomyosarcoma (ERMS) is the most common subtype of RMS, occurring in soft tissue and visceral sites of young children, and is associated with favorable outcomes. A subset occurs in mucosal-lined luminal structures, displaying a unique grape-like growth termed as "botryoid-type." To further delineate the differences between conventional (cERMS) and botryoid-type (bERMS) RMS, we performed a comparative histologic review and comprehensive molecular profiling of 48 cases (25 bERMS and 23 cERMS). All tumors were subjected to a hybridization capture-based targeted matched tumor-normal DNA NGS assay...

Schlafen 11 (SLFN11), a DNA/RNA helicase, acts as a regulator of cellular response to replicative stress and irreversibly triggers replication block and cell death. Several preclinical in vitro studies and clinical trials established that SLFN11 expression predicts outcomes in patients with advanced cancer treated with DNA-damaging chemotherapeutics and more recently with poly(ADP-ribose) polymerase inhibitors. SLFN11 expression status remains unknown in many cancer types, especially in mesenchymal tumors. This study evaluated a cohort of well characterized 3808 epithelial and 2850 mesenchymal and neuroectodermal tumors for SLFN11 expression using immunohistochemistry...

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) is a rare form of aggressive B-cell lymphoma with limited molecular information reported regarding interferon regulatory factor 4 (IRF4) status. Here, we presented 3 EBV-positive DLBCL cases with IRF4 rearrangement (EBV+DLBCL-IRF4-R) verified by fluorescence in situ hybridization (FISH). Three patients, including 1 male and 2 females (median age: 64 y; range: 45 to 68 y), had normal immune function. During a median follow-up of 12 months (range: 0 to 24 mo), 2 patients succumbed to the disease, and 1 patient achieved complete response...

BRAF fusion Spitz neoplasms along with MAP3K8 fusions are among the subtypes of Spitz most likely to be diagnosed as Spitz melanoma. However, the current literature has only limited amounts of clinical follow-up on these cases. In this study, we share our experience with 39 BRAF fusion Spitz neoplasms and provide the greatest number of cases with available clinical follow-up. Among 24 patients with clinical follow-up (mean duration of 26.1 mo), none developed metastatic disease. Detailed biomarker assessment with FISH studies, TERT promoter mutational analysis, PRAME and p16 IHC also strongly favored a benign process...

No abstract text is available yet for this article.

Loss of S-methyl-5'-thioadenosine phosphorylase (MTAP) expression is a common event in cancer leading to a critical vulnerability of cancer cells towards anti-cancer drugs. Homozygous MTAP deletions result in a complete expression loss that can be detected by immunohistochemistry (IHC). In this study, a tissue microarray containing 17,078 samples from 149 different tumor entities was analyzed by IHC, and complete MTAP loss was validated by fluorescence in situ hybridization. MTAP loss was observed in 83 of 149 tumor categories, including neuroendocrine neoplasms (up to 80%), Hodgkin lymphoma (50...

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...

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...

No abstract text is available yet for this article.

Pulmonary complications continue to cause significant morbidity and mortality in posthematopoietic stem cell transplantation (HSCT) settings. The histopathology of pulmonary diseases in the post-HSCT context is poorly characterized, especially in the pediatric population. We sought to characterize the pathologic spectrum of pulmonary disease post-HSCT in a pediatric cohort. Fifty-six specimens, including 53 biopsy specimens, corresponding to 53 patients, were identified. Biopsy slides were reviewed and assigned to diagnostic categories (infectious, graft-versus-host disease, vasculopathy, indeterminate, and others) by consensus among 3 pediatric pulmonary pathologists, taking into consideration pathologic, clinical, radiologic, and laboratory findings...

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...

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...

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...

Differences in risk factors (RF) of lymph node metastasis (LNM) and prognosis between submucosal early gastric cardiac (SEGCC) and noncardiac (SEGNCC) carcinomas remain unclear. In this study, we investigated and compared RF of LNM and prognosis in 891 patients with radical gastrectomy for SEGCC (n=217) or SEGNCC (n=674). Compared with SEGNCC, SEGCC displayed significantly higher proportion of elderly patients (70 y or above), the elevated macroscopic type, well/moderately differentiated tubular and low-grade papillary adenocarcinomas, as well as low-grade tumor budding, but lower prevalence of the depressed macroscopic type, poorly differentiated tubular adenocarcinoma, mixed adenocarcinoma, poorly cohesive carcinoma, lymphovascular invasion (LVI), perineural invasion, and high-grade tumor budding...

The guidelines recently recognized the intra-ampullary papillary tubular neoplasm (IAPN) as a distinct tumor entity. However, the data on IAPN and its distinction from other ampullary tumors remain limited. A detailed clinicopathologic analysis of 72 previously unpublished IAPNs was performed. The patients were: male/female=1.8; mean age=67 years (range: 42 to 86 y); mean size=2.3 cm. Gross-microscopic correlation was crucial. From the duodenal perspective, the ampulla was typically raised symmetrically, with a patulous orifice, and was otherwise covered by stretched normal duodenal mucosa...

Pulmonary thrombotic arteriopathy (PTA) can be an incidental finding in lung resections performed for various indications. Historic studies largely examined PTA in autopsies. Thus, the prevalence in surgical samples, particularly in the modern era of lung cancer screening, is poorly defined. Detection of PTA in surgical samples may provide an opportunity for therapeutic intervention, but the impact of this finding on clinical management is unknown. We retrospectively examined consecutive lung surgical resections containing a report of incidental PTA between 2019 and 2022 in our institution...

The three-tier (A vs. B vs. C) pattern-based (Silva) classification system is a strong and fairly reproducible predictor of the risk of lymph node involvement and recurrence of human papillomavirus (HPV)-associated endocervical adenocarcinoma (EA). Recently, a binary pattern-based classification system has been proposed which incorporates the Silva pattern and lymphovascular invasion (LVI) to assign tumors as "low risk" or "high risk" and this may have superior prognostic significance compared with the three-tier system as well as current International Federation of Gynecology and Obstetrics (FIGO) staging of cervix-confined disease...