International Journal of Surgical Pathology最新文献

Perianal mucinous adenocarcinoma is an uncommon entity that can be mistaken for perianal fistulous lesions due to its association with fistulas and its confinement to the perianal region. It is a diagnosis of exclusion of secondary anorectal, cutaneous, urogenital, and metastatic carcinomas. Its etiology is controversial with many speculated risk factors. Previous case reports and small case series have mainly focused on clinical and radiologic diagnoses and treatment options. We performed a retrospective review study of perianal carcinomas over 15 years focusing on the histopathologic and immunohistochemical features of perianal mucinous adenocarcinomas. We found 3 adult male patients (average age: 55 years) with primary fistula-associated perianal mucinous adenocarcinoma. The patients had a long history of recurrent discharging sinuses and fistulas involving the perianal, perineum, and gluteal regions. They had nonhealing perianal fistulas related to hidradenitis suppurativa and Crohn's disease, that antedate mass lesions by more than 5 years, despite surgical and medical treatments. The patients were smokers with diabetes. The tumors were low-grade well-differentiated carcinomas characterized by mucin pools with floating and lining neoplastic epithelium and intraluminal villoglandular growths. Characteristically, they showed a direct continuity between the neoplastic epithelium and perianal epidermis in sinus openings, abrupt transitions to squamous epithelium in epithelized fistulous tracts, and foci of intestinal metaplasia. They expressed CDX2, keratin7, keratin20, MUC1, MUC2, and MUC5AC, showed membranous staining for beta-catenin, and were negative for AMACR, GCDFP15, and MUC6, indicating an extramucosal, intestinal-type, rectal-immunophenotype mucinous carcinoma. Primary fistula-associated perianal mucinous adenocarcinomas have distinct diagnostic clinicopathologic criteria and potential precursor lesions.

SMARCB1/INI1 (integrase interactor 1) deficient undifferentiated carcinomas of the gastrointestinal tract are highly aggressive neoplasms with a poor clinical outcome. Due to their rarity, the clinicopathological characteristics and molecular profiles of these tumors remain incompletely understood. In this report, we describe the first documented undifferentiated carcinoma with INI1 deficiency that originated in the gallbladder. Histological examination revealed a tumor composed of sheets of dyscohesive cells exhibiting a rhabdoid morphology. Immunohistochemical analysis confirmed the diagnosis of carcinoma with complete loss of INI1 expression. The diagnosis of INI1-deficient undifferentiated carcinoma can be challenging, and correlation of clinical findings, in conjunction with comprehensive immunohistochemical and molecular investigations, is crucial to establish the correct diagnosis and exclude potential mimicking entities.

Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory breast disease. Patients typically present with a painful or painless mass and signs of inflammation. While IGM is already rare in women, only a few male patients have been reported in the literature. In this article we present the case report of a 63-year-old male patient with IGM, which clinically and radiologically mimicked male breast cancer. Radiological findings in the patient were nonspecific. Definitive diagnosis was made by histopathological evaluation. Surgical excision was performed as a treatment modality. No recurrence or residual lesion was detected in postoperative follow-up.

BackgroundPD-L1 expression guides immunotherapy decisions in non small cell lung cancer (NSCLC), yet sample type can impact assessment accuracy. This study aimed to compare PD-L1 expression between small (biopsies, cell blocks) and large (resection) NSCLC samples, assess interobserver variability, and examine whether PD-L1 scoring trends remained stable over a multi-year period.MethodsA retrospective analysis was conducted on 494 NSCLC patients tested for PD-L1 (Ventana SP263) between 2018 and 2022. Sample type, tumor subtype, PD-L1 tumor proportion score (TPS), and reporting pathologist were recorded. Interobserver variability was analyzed based on routine diagnostic reports from different pathologists evaluating non-overlapping patient cohorts. Additionally, a subset of 43 patients had matched cell block and resection specimens collected from the same tumor, allowing direct comparison between preparations.ResultsAmong the 494 NSCLC specimens, 152 were large and 342 were small samples. TPS results showed 112 samples (22%) with TPS ≥ 50%, 163 (34%) with TPS 1%-49%, and 219 (44%) with TPS < 1%. No significant differences in TPS categories were observed between cell blocks and tissue samples (p = 0.176) or between small and large samples (p = 0.326). TPS distributions across different pathologists (p = 0.260) and years (p = 0.250) remained consistent. In the matched 43 specimens, TPS concordance between cell block and resection was high (κ = 0.892).ConclusionSmall biopsies and cell blocks provide reliable PD-L1 results comparable to resection specimens, supporting their use for PD-L1 testing in clinical settings to enhance timely immunotherapy access for NSCLC patients.

BackgroundLymphomas involving gynecologic organs often occur in the ovaries, and uterine cervix. Uterine corpus, vagina, and vulva are less common locations involved. Although female genital tract lymphomas are uncommon, it is important for the gynecologists and pathologists to be aware of this entity as it potentially could be the first presenting location of lymphoma or involved secondarily.MethodsPathology of lymphomas first diagnosed in and secondarily involving gynecologic organs from January 2005 to January 2024 were retrieved from our institution's pathology databases, and their clinicopathological features were reviewed.ResultsA total of 19 patients with lymphomas involving the gynecological organs were identified with 17 patients being first-time diagnosed with lymphomas on gynecologic surgical pathology specimens and 2 patients with prior history of lymphoma. The average age of patients with lymphoma diagnosed initially in the gynecologic tract was 59.2 years (range 20-83 years). The two patients with prior lymphoma histories had diffuse large B-cell lymphomas (DLBCL) with one transformed from prior retroperitoneal low-grade follicular lymphoma. The cervix was the most frequent location of first-time diagnosed lymphomas, comprising 8 of 17 specimens (47%), followed by bilateral ovaries and fallopian tubes (41%), endomyometrium (12%), and vagina (6%). The types of first diagnosed gynecologic lymphomas were DLBCL (65%), follicular lymphoma (18%), lymphoplasmacytic lymphoma (6%), Burkitt lymphoma (6%) and extranodal marginal zone B-cell lymphoma (MZBCL) (6%). When the criteria of defining primary gynecologic lymphomas were applied, 7 of 17 first-time diagnosed lymphomas in the gynecologic tract were actually primary gynecologic lymphomas without distant disease, peripheral blood or bone marrow involvement, including 5 cervical primary, one endometrial primary and one vaginal primary lymphoma.ConclusionOur study confirmed that the most common lymphomas involving the gynecologic tract were DLBCL and follicular lymphoma, with rare incidence of Burkitt lymphoma, extranodal MZBCL and lymphoplasmacytic lymphoma. Misdiagnosing gynecologic lymphomas as high-grade/undifferentiated carcinoma or sarcoma is a real risk for surgical pathologist, especially during frozen sections.

Histiocytic sarcoma is a malignant neoplasm with cells showing morphologic and immunohistochemical features of histiocytes. The lung and stomach are rare sites of involvement, and few have been reported in the existing literature. We report a 72-year-old woman with primary histiocytic sarcoma involving the right lung, stomach, and bilateral adrenal glands. Computed tomography revealed a large heterogeneous mass in the upper lobe of the right lung, regional lymphadenopathy, and masses within the bilateral adrenal glands. Gastric involvement was discovered via polypectomy during a routine gastric endoscopy. Morphologically, the lung and stomach specimens showed sheets of large and spindle cells with increased mitotic figures. Immunohistochemical staining revealed CD163, CD68, and CD4 expression in the lung tumor and CD163 and CD4 in the gastric tumor. The patient deteriorated rapidly and died of a pulmonary infection two months after diagnosis. Surgical resection remains the most effective treatment. However, for those with advanced disease, systemic chemotherapy alone may be the only available option, but the outcomes are variable. Advancements in targeted therapy are needed to improve treatment outcomes for patients with multi-organ involvement of histiocytic sarcoma.

Genitourinary tract lymphomas are rare and comprise <5% of extranodal lymphomas. Information on prevalence in urinary and male genital tract (GU) organs is limited. A retrospective study of the B-cell lymphomas in the GU organs (kidney, prostate, bladder, testis, and ureter) between January 1, 2011, and September 16, 2021, at our institution was performed. A total of 39 specimens with lymphoma in the GU organs were identified, 51% of which were primary. The most common diagnosis within the primary subgroup was diffuse large B-cell lymphoma (60%), followed by chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL, 15%) and extranodal marginal zone lymphoma (EMZL, 15%) and follicular lymphoma (5%). Kidney was the most common site (36%), followed by testes (20%), bladder (15%), and prostate (13%). All testicular lymphomas were primary. Most bladder lymphomas were secondary (83%). Most of these were either discovered incidentally or presented with organ-specific symptoms. We also identified an interesting example of primary EMZL involving both prostate and bladder and another one of proliferative glomerulonephritis with monoclonal IgG kappa immunoglobulin deposits due to primary CLL/SLL of the kidney. Our study highlights the importance of hematopathologic workup for specimens suspicious for a typical B cell infiltrates in surgical pathology practice.

Rosai-Dorfman disease (RDD) represents a clinicopathological entity within the spectrum of histiocytic neoplastic disorders, characterized by histiocytic proliferation with distinctive histopathological features and heterogeneous clinical presentations. We report an unusual presentation of thymic RDD in a 38-year-old female patient, with an anterior mediastinal soft tissue mass identified on computed tomography. Histologically, sections of the thymus demonstrated characteristic RDD features accompanied by a complex microenvironment containing both necrotizing and nonnecrotizing granulomatous inflammation. Immunohistochemical stains revealed diffuse positivity for S-100, CD68, and OCT2 in the lesional histiocytes, with focal cyclin D1 expression and absence of CD1a immunoreactivity. CD20, CD5, and CD3 highlighted surrounding reactive B-cell and T-cell lymphocytes. The patient's postoperative course was unremarkable. Subsequent 3-month surveillance demonstrated no evidence of disease recurrence.

Background. Male breast carcinoma is a rare, hormonally driven neoplasm constituting 0.1% of all malignancies. Molecular studies have identified 1000 genes differentially expressed between male breast carcinoma and female breast cancer with an up-regulation of androgen receptor (AR) related genes and X chromosome gain in male breast cancer. NKX3.1, an androgen-regulated homeobox gene, also has a stem cell signature. In prostate carcinoma, NKX3.1 expression correlates with AR. Although male breast cancer has greater AR expression, the expression profile of NKX3.1, as well as its correlation with AR, remains to be elucidated. Methods. This was a retrospective study conducted in a North Indian tertiary-care oncology institute. A clinicopathological review of registered male breast carcinoma patients from January 2020 to December 2024 was conducted. AR and NKX3.1 immunohistochemistry were attempted. Results. There were 57 patients of male breast cancer constituting 1.2% (57/4600) of all the breast carcinoma patients. The median age of diagnosis was 61 years. AR expression was observed in 83% of tumors (n = 44/53). NKX3.1 expression was observed in 23% of tumors (n = 12/53), which were predominantly grade 3 (n = 10/12, 83%), luminal B tumors. All NKX3.1 positive tumors expressed AR suggesting biological association. AR-expressing tumors had a longer duration of symptoms (P = .044) and had a significant association with the molecular subtype. Conclusion. NKX3.1 expression in male breast cancer is intriguing and needs to be explored in terms of tumor stemness. To the best of our knowledge, this is the first study evaluating AR and NKX3.1 expression in a single cohort of male breast carcinoma.

Introduction.Increased steatosis on preimplant liver frozen section is associated with delayed graft function and primary nonfunction. Efforts to standardize histologic assessment have proven difficult. Frozen section artifact and lipopeliosis complicate the detection of steatosis. We aimed to develop and validate an AI model to recognize large droplet fat and fat induced artifact (FIA)/lipopeliosis on preimplantation frozen section and to correlate the AI results with post-transplant clinical parameters.Methods.The model was applied to 161 consecutive liver transplant specimens with preimplant slides. Results were correlated with traditional and Banff histologic assessment and clinical parameters.Results.By traditional assessment, steatosis ranged from 0%-40%. The AI model identified a range of 0 to 15.9% steatosis. There was no difference in patient survival by any measures of steatosis. AI steatosis correlated with increased risk of early allograft dysfunction (OR = 1.63, P < .001), respiratory failure (OR = 1.21, P = .003), and more advanced fibrosis (OR = 1.18, P = .030), but was not correlated with graft or patient survival. FIA/lipopeliosis were identified in a range of 0 to 6.42%. In univariate analysis the percentage of FIA/lipopeliosis correlated with both graft and patient survival (P = .044 and P = .009, respectively), but was not associated with increased risk of early allograft dysfunction, respiratory failure, or advanced fibrosis.Conclusions.We developed an AI model that quantitates large droplet fat and FIA/lipopeliosis on frozen section slides and found a correlation with post-transplant outcomes. Further studies on larger, multi-institutional cohorts with higher fat containing donors are necessary to determine the role this model may have in organ acceptance decisions.