International Journal of Surgical Pathology最新文献

Russell body gastritis is a discrete morphologic pattern of chronic gastritis, characterized by numerous plasma cells filled with intracytoplasmic Russell body inclusions. It can be mistaken for neoplastic lesions and for extracellular hyaline structures. We report three adult men with Russell body gastritis. The patients were diagnosed and treated for various hematolymphoid disorders. During follow-up, they presented with abdominal pain, gastric erythema and thickening. One patient had Helicobacter pylori infection. The gastric biopsy showed an expanded lamina propria filled with numerous plasma cells containing hyaline glassy globules. Initial hematoxylin and eosin impression included amyloidosis, gastric antral vascular ectasia, neuroendocrine tumor, plasma cell neoplasm and low-grade lymphoma with plasmacytic features. The inclusions showed a homogenous magenta staining pattern with periodic acid-Schiff and diastase, a central dark red core surrounded by a bluish ring with Masson trichrome, and were apple-green with mucicarmine. Although they showed an orangeophilic amyloid-like staining pattern with Congo red, they were not birefringent. The inclusions were metachromatic and nested in clefted lacunar spaces. The plasmacytoid and rhabdoid cells expressed CD45, CD38, CD138, CD79a and epithelial membrane antigen. They were polytypic with kappa and lambda light chains. The immunomarkers showed a characteristic reticulated network surrounding the inclusions, creating a negative image. Russell body gastritis is a rare and special form of chronic gastritis. It can be mistaken for various lesions. Histochemical and immunohistochemical stains are useful ancillary diagnostic tools. The occurrence of this phenomenon in certain patients with compromised immune systems is clinically significant and requires validation.

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal neoplasms defined by co-expression of melanocytic and smooth muscle markers, with fibroma-like PEComa representing a novel and recently described subtype strongly associated with tuberous sclerosis complex (TSC). This article reports the eighth documented example of fibroma-like PEComa, occurring in the subcutaneous wrist tissue of a 6-year-old girl with no prior clinical or family history of TSC. Histopathological examination revealed a hypocellular to moderately cellular proliferation of bland oval, spindle to stellate cells within dense collagenous stroma, accompanied by focal myxoid change and scattered mature adipose tissue. Immunohistochemically, the tumor exhibited diffuse strong glycoprotein nonmetastatic melanoma protein B (GPNMB) expression and focal positivity for HMB45, melan-A, and desmin. DNA-based target next-generation sequencing identified a germline TSC2 nonsense mutation (c.268C > T, p.Q90*) with a variant allele frequency of 83%, confirmed via peripheral blood testing, leading to a definitive diagnosis of TSC. A review of all 8 reported tumors confirms that fibroma-like PEComa occurs predominantly in children and young adults, shows a female predilection (5:3), and favors extremity locations. These tumors typically demonstrate benign behavior with no recurrences or metastases reported. Our report highlights that fibroma-like PEComa can serve as an early indicator of occult TSC and underscores the diagnostic utility of GPNMB immunohistochemistry as a surrogate marker of TSC1/2/MTOR pathway activation. Comprehensive clinical and genetic evaluation for TSC is recommended upon diagnosis of this rare tumor.

Aim: Molecular classifications in gastric cancer are expensive and require experience. This study aimed to establish a molecular-like classification and to investigate the correlation of the classification with clinicopathological features and its prognostic significance. Materials-Methods: In 202 gastric cancer patients who underwent surgery between 2011 and 2019, the clinicopathological features of the tumors were re-evaluated, and the tumors were grouped by molecular-like classification using immunohistochemistry (MLH1, PMS2, MSH2, MSH6, p53, E-cadherin) and chromosomal in situ hybridization (EBER): EBV positive tumors (EBV+), tumors with microsatellite instability (MSI), genomically stable tumors (GS), chromosomal unstable tumors (CUN) and unclassifiable gastric tumors (G-NOS). Results: Twelve of the patients were in the EBV+, 22 in the MSI, 27 in the GS, 76 in the CUN and 65 in the G-NOS group. EBV + tumors were associated with high-grade tubular/papillary morphology and GS tumors were associated with poorly cohesive/mixed type, while tumors in the MSI group were associated with low-grade tubular/papillary morphology (p < .0001). Marked tumor budding was the least in MSI tumors and the most in GS tumors (p = .018). The longest survival time was in the patients of EBV + group, while the shortest survival time was in the patients of GS group (p = .029). Cox regression analysis indicated that age, lymphovascular invasion, positive surgical margins, low-grade tubular and papillary histological types, two groups within molecular- like classification (MSI and GS) were independent prognostic factors (p < .05). Conclusion: Molecular-like classification holds promise as a low-cost, easy-to-implement classification that can be used predictively in prognosis. However, molecular-based studies with large series are still needed to determine whether it is a pretest or alternative of molecular classifications.

Glomus tumors, rare neoplasms showing differentiation resembling the glomus body associated with the skin, present significant diagnostic challenges due to their rarity and potential for misdiagnosis. This study reports on a 26-year-old woman whose imaging initially suggested renal cell carcinoma; however, histopathological analysis of the partial nephrectomy identified the mass as a glomangioma. Alongside this report, we provide a comprehensive review of the literature, emphasizing the importance of histopathological examination in differentiating these tumors. The unique hereditary findings of this report contribute to the limited, but crucial understanding of renal glomus tumors, highlighting the need for awareness and careful evaluation of renal masses, particularly due to their nonspecific imaging features.

Metastasis to the female genital tract is a rare event and presents a significant diagnostic challenge. Among the organs of the female genital tract, the uterine cervix is an exceptionally uncommon site for metastasis, likely due to its limited vascular perfusion and abundant fibrous tissue. The most common clinical presentation is abnormal vaginal bleeding, seen in 62% to 75% of patients. Accurate identification of cervical tumors, whether primary or metastatic, is necessary for proper treatment and prognostic assessment. In this case series, we present the clinicopathologic features of six patients with metastatic cancer to the uterine cervix encountered over a 5-year period.

Acquired cystic kidney disease-associated renal cell carcinoma (ACKD-RCC) can develop in the kidneys of patients with chronic kidney disease, particularly those on long-term dialysis, and displays morphologic diversity. We present a 70-year-old man with acquired cystic disease who developed 3 discrete tumors, each with different morphology. The patient had been on hemodialysis for 22 years and underwent right nephrectomy for a newly detected kidney mass. Histopathology and immunohistochemistry revealed 3 discrete tumors: a superior polar tumor displaying classic ACKD-RCC architecture with PAX8, AMACR, and KRT7 expression; an inferior polar tumor displaying ACKD-RCC morphology combined with a high-grade sarcomatoid component with PAX8 expression without AMACR and KRT7, consistent with dedifferentiation; and a midkidney tumor consisting mainly of bland spindle cells in fascicles with PAX8 and focal KRT7 expression confirming its epithelial origin, and negative mesenchymal and melanocytic markers excluding mimics, leading to a diagnosis of renal cell carcinoma (RCC), not otherwise specified (NOS). The patient developed pulmonary and bone metastases postoperatively and died of the disease 3 months later. The synchronous occurrence of conventional ACKD-RCC, a dedifferentiated sarcomatoid form, and a spindle cell RCC, NOS demonstrate the marked morphological heterogeneity of neoplasia in ACKD. The presence of both sarcomatoid and spindle cell histologic patterns is associated with an aggressive clinical course, highlighting the importance of intensive surveillance and thorough pathological evaluation of kidney masses in patients on long-term dialysis.

Primary alveolar rhabdomyosarcoma arising in the uterus is an extremely uncommon entity and is often a diagnosis of exclusion. Rapid uterine enlargement and per-vaginal bleeding are the commonest clinical presentations of this tumour. In the absence of such symptoms, diagnostic delays are not uncommon. An elderly woman presented with abdominal distention and weight loss of 12 months duration with no prior gynaecological symptoms. Imaging showed a large, heterogeneous uterine mass reaching up to the epigastrium, with no evidence of distant metastases. An image-guided biopsy suggested a high-grade sarcoma. She underwent standard surgical staging, which included total abdominal hysterectomy, bilateral salphingo-oophorectomy and pelvic lymphadenectomy. The histopathological examination and immunohistochemical studies established the diagnosis of a primary uterine rhabdomyosarcoma, which was later confirmed to be of the alveolar subtype by a positive translocation of the FOXO1 gene on fluorescence in situ hybridization. Primary uterine alveolar rhabdomyosarcoma is rare in adults. The immunohistochemistry and translocation studies are important to establish the diagnosis, especially when presenting symptoms are non -specific.

Ten spindle cell thymomas with prominent angiomatoid features are presented. The patients, consisting of 8 men and 2 women, are between the ages of 47 and 62, with an average age of 54.5. Clinically, 8 patients experienced chest pain, cough, and dyspnea, while 2 patients were asymptomatic. Diagnostic imaging revealed an anterior mediastinal mass in all patients, leading to surgical resection. The resected neoplasms varied in size from 3 to 5 cm in diameter and were described as well-circumscribed, hemorrhagic, with solid areas. Histologically, they exhibited extensive areas of hemorrhage with scant cellularity. In the more solid areas, the spindle cell proliferation was mixed with dilated vascular structures. Seven neoplasms were encapsulated, while three were minimally invasive, with tumoral cells invading the perithymic adipose tissue. Immunohistochemical stains showed the spindle cells were positive for keratin AE1/AE3, keratin 5/6, p63, and weakly positive for p40, but negative for vascular markers CD31 and CD34. Clinically, eight patients are alive without recurrence, while two were lost to follow-up. The histopathological features of these spindle cell thymomas represent an unusual subtype that can mimic primary vascular neoplasms, which may require different treatment and have varied outcomes.

Gastrointestinal stromal tumor accounts for approximately 80% of mesenchymal tumors and 1% to 3% of all gastrointestinal system malignancies. KIT or PDGFRA mutations are identified in approximately 92-93% of gastrointestinal stromal tumors. Both KIT and PDGFRA mutations are associated with tyrosine kinase receptor signaling pathways and are considered mutually exclusive. Herein, we report a patient with sporadic multiple gastrointestinal stromal tumors harboring mutually exclusive KIT and PDGFRA mutations in separate tumors and review similar patients in the literature.Patient PresentationA 60-year-old male patient presented with abdominal pain. Abdominal computed tomography revealed two distinct lesions in the stomach. The patient underwent distal gastrectomy, and pathological examination demonstrated that both lesions were gastrointestinal stromal tumors. Interestingly, the tumors exhibited different morphologies (epithelioid and spindle cell), distinct immunohistochemical profiles, and harbored different mutations (KIT and PDGFRA).ConclusionSporadic multiple gastrointestinal stromal tumors may have different morphological and immunohistochemical features, and they may also harbor two mutually exclusive mutations, such as KIT and PDGFRA. Recognition of this possibility is crucial for accurate diagnosis and the development of personalized therapy.