Lipoblastomatosis is a rare benign adipocytic tumour of infancy and early childhood, characterized by rapid growth. Diagnosis is challenging, owing to tumour heterogeneity and overlap with other pediatric soft-tissue neoplasms. PLAG1 rearrangement is the defining molecular hallmark, with an expanding list of fusion partners. We report a case of a 1-year-old child with a firm, nonmobile mass in the right thigh, which on CECT was deep-seated and heterogeneously enhanced. Gross evaluation of the excision specimen demonstrated an ill-circumscribed soft tissue mass. Histopathologically, the tumour showed myxoid nodules with primitive mesenchymal spindle-cell areas, and peripheral adipose tissue containing scattered lipoblasts, features suggestive of lipoblastomatosis. The IHC study showed S100 and CD34 positivity in adipocytes, and desmin and myogenin positivity in spindle-cell components. Molecular testing by NGS revealed a COL1A2::PLAG1 gene fusion, thus further establishing the diagnosis. Differentials such as myxoid liposarcoma, fibrous hamartoma of infancy, and infantile fibrosarcoma also harbour distinct genetic drivers, including EWSR1::DDIT3, EGFR exon 20 alterations, and ETV6::NTRK3, respectively. This case highlights the diagnostic workup of soft-tissue tumours and underscores the importance of integrating histopathology, IHC, and molecular testing. Identification of PLAG1 rearrangement is crucial for confirming the diagnosis. With the growing number of molecularly defined soft-tissue tumours of diagnostic and prognostic significance, incorporating molecular analysis is essential in the evaluation of soft-tissue lesions.
Multisystem inflammatory syndrome in children (MIS-C) represents a severe postinfectious hyperinflammatory condition following SARS-CoV-2 infection. Despite extensive clinical characterization, histopathologic data-especially from pre-mortem pediatric biopsies-remain scarce. We report a 9-month-old male infant with confirmed SARS-CoV-2 infection and rapid multiorgan failure. Pre-mortem incisional biopsies from the myocardium, lung, and pleura revealed degenerative myocyte changes, endothelial swelling, and fibrin-platelet microthrombi consistent with thrombotic microangiopathy. Immunohistochemistry demonstrated mild CD3+ T-cell-predominant infiltrates and focal SARS-CoV-2 antigen positivity confined to alveolar and bronchiolar epithelium, while myocardial and pleural tissues were negative. These findings highlight early morphologic correlates of immune-mediated vascular injury in MIS-C, characterized by endothelial dysfunction, microvascular inflammation, and T-cell-driven immunopathology in the absence of direct viral cytopathy. This case provides rare pre-mortem evidence of immune-thrombotic endotheliopathy in an infant, bridging clinical and histologic manifestations of pediatric SARS-CoV-2-associated hyperinflammatory disease.
OBJECTIVE:Colorectal cancer (CRC) is the third most common type of cancer worldwide and the fourth most common cause of cancer-related deaths. Innovative approaches like immunotherapy are necessary for treatment-resistant patients with a poor prognosis. This study aimed to investigate the status of CTLA-4, one of the immune checkpoint molecules, in CRCs. MATERIAL AND METHODS:A total of 183 resected CRCs were analyzed retrospectively. Immunohistochemical staining was conducted using an anti-CTLA-4 antibody. The relationship between CTLA-4 and prognostic parameters, such as HER2 and microsatellite instability (MSI), was investigated. RESULTS:One hundred and four of the cases were male, and 79 were female. One hundred fifty-nine of the cases were conventional adenocarcinomas, while 24 were mucinous adenocarcinomas. In 53 of the cases (29%), CTLA-4 showed less than 1% staining in the immune cells, classifying it as negative. In the remaining cases (71%), varying degrees of immune cell staining with CTLA-4 were observed. Conventional adenocarcinomas exhibited a higher expression of CTLA-4 compared to mucinous carcinomas. No statistically significant correlation was found between MSI status and CTLA-4 immune cell staining (p = 0.572). CTLA-4 positivity decreased significantly as tumor diameter decreased (p = 0.029). There was no correlation between the CTLA-4 immunostaining and median survival time. CONCLUSION:CTLA-4 expression was detected in 71% of CRCs. CTLA-4 positivity significantly decreased as tumor diameter decreased. There was no significant association between CTLA-4 expression and MSI or other prognostic parameters. Additionally, no significant correlation was found between CTLA-4 expression and median survival time. Nevertheless, the presence of CTLA-4 expression in the majority of CRCs is promising for anti-CTLA-4 therapy.
The presence of lymphoid cells with flower-like nuclei in peripheral blood is an uncommon morphologic finding, classically associated with Human T-lymphotropic virus type 1 (HTLV-1) infection related Adult T-cell Leukemia/Lymphoma (ATLL). However, similar cytologic features may be observed in other hematolymphoid malignancies. To describe cases of hematologic neoplasms presenting with flower cells in the peripheral blood and to highlight their broader diagnostic spectrum. We report a series of patients with distinct hematologic malignancies who demonstrated flower cells on peripheral blood smear, thereby expanding the morphologic differential beyond ATLL. Recognition that flower-like nuclear morphology may occur outside the context of ATLL is important for accurate diagnosis and underscores the need to consider a boarder range of hematolymphoid neoplasms in the differential.
OBJECTIVE:Invasion can be detected in up to 50% of excision specimens in cases diagnosed with ductal carcinoma in-situ (DCIS) in tru-cut biopsies. The predicting of invasion is critical for managing the treatment. The objective of this study was to ascertain the predictive role of histological characteristics and estrogen receptor (ER) and HER2 expression of DCIS with respect to invasion and to create an artificial intelligence (AI)-assisted invasion risk scoring. MATERIAL AND METHODS:A total of 140 tru-cut biopsies with DCIS were included. We evaluated the predominant structural pattern, nuclear grade, presence of comedonecrosis, and ER/HER2 expressions and their relationship with invasion upstage. Based on the results, an invasion risk scoring system was created using OpenAI-ChatGPT 5.2. RESULTS:Of the 140 cases, 70 (50%) were high-grade (DCIS-3), 49 (35%) were intermediate-grade (DCIS-2), and 21 (15%) were low-grade (DCIS-1). DCIS-1 and DCIS-2 showed significant association with a cribriform pattern, and DCIS-3 showed with a solid pattern. When the results were compared with those of the final specimens, invasion upstaging occurred in 9.5% of DCIS-1, 38.7% of DCIS-2, and 52.8% of DCIS-3 cases. A solid pattern, high nuclear grade, comedonecrosis, and ER-/HER2- profile showed high correlation with invasion. In AI-assisted risk scoring, DCIS cases were divided into three groups: low, medium, and high risk. The invasion upstaging rates in these groups were 11.44%, 28.97%, and 64.19%, respectively. CONCLUSION:DCIS with high nuclear grade, comedonecrosis, a solid pattern, and the ER-/HER2+ or ER-/HER2- immunoprofile should be considered high risk for invasion. They should be approached as invasive tumors and evaluated in terms of lymph node staging and neoadjuvant treatment.
