ANO1 (Anoctamin 1)

Prognosis depends primarily on tumour location, size and mitotic index. In high-risk cases, adjuvant imatinib therapy is warranted.

These tumors express diagnostic GIST markers (c-Kit and DOG1) and show significant response to the BRAF inhibitor dabrafenib. This model recapitulates key histopathological and molecular features of human BRAF-mutant GIST and provides a valuable platform for studying tumor initiation, progression, and therapeutic resistance. Importantly, it allows for preclinical testing of targeted therapies in BRAF GIST, offering new insights into treatment strategies.

We report the case of a 49-year-old woman diagnosed with peritoneal sarcomatosis secondary to an epithelioid gastrointestinal stromal tumor (GIST) (Ki-67 3%, CD117 and DOG1 positive), initially managed with empirical carboplatin-paclitaxel, which was discontinued after histological confirmation. Treatment with imatinib 400 mg/day was initiated, achieving sustained metabolic response and clinical stability. After 12 months of targeted therapy, the patient underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) using mitomycin C. Intraoperative findings revealed extensive peritoneal disease with distal jejunal involvement, achieving CC-1 cytoreduction...At one-year follow-up, the patient remains clinically stable, with preserved functional status and no evidence of radiological progression. This case illustrates the potential role of a multimodal strategy combining targeted therapy, CRS, and HIPEC in selected patients with peritoneal involvement from GISTs.

Targeted tyrosine kinase inhibitors (TKIs) have transformed GIST management, with imatinib as the foundational first-line therapy and subsequent agents, sunitinib, regorafenib, avapritinib, and ripretinib, addressing primary or secondary resistance driven by diverse mutational patterns. Emerging therapeutic directions include next-generation kinase inhibitors, heat shock protein inhibitors, immunotherapy, metabolic and epigenetic targeting, and biomarker-driven individualized treatment strategies. This review synthesizes contemporary advances in the histopathological, molecular, and therapeutic landscape of GISTs, emphasizing an integrated diagnostic approach and highlighting ongoing efforts to overcome therapeutic resistance and optimize personalized care.

Molecular testing identified a KIT Exon 9 mutation, leading to initiation of imatinib therapy...Multidisciplinary approaches combining imaging, histology, and molecular profiling are essential for optimizing outcomes in these complex cases. This extra-GI/pelvic GIST occurred under chronic posttransplant immunosuppression after renal and liver transplantation; as such, we highlight the transplant-oncology interface, notably, an elevated posttransplant cancer risk, rare but documented GIST after kidney transplant, and TKI-calcineurin-inhibitor interactions that require coordinated management.

This case report presents a highly unusual case of a primary high-grade malignant peripheral nerve sheath tumor (MPNST) of esophagus, a neoplasm of extreme rarity, with fewer than twenty histologically confirmed cases reported worldwide to date; detailing the successful management of this tumor through Orringer's transhiatal esophagectomy, complemented by comprehensive histopathologic and immunohistochemical evaluation. Our report emphasizes the crucial the role of immunohistochemistry, specifically the diagnostic value of S100, SOX10, and the exclusion of gastrointestinal stromal tumors markers (DOG1, CD117) in distinguishing MPNST, from morphologically similar esophageal submucosal tumors.

P=N/A, N=66, Not yet recruiting, Peking University International Hospital; Peking University International Hospital

Yet for most TMEMs, only pre-clinical or early-phase data exist, with many supported by a single study lacking independent validation. This review brings together scattered evidence on TMEM proteins in lung cancer, with the aim of guiding future work on their possible use as biomarkers or therapeutic targets.

Moderate to strong immunohistochemistry for DOG1 has been found in several other tumors, sometimes comparable to that of GISTs. This suggests that DOG1 should not be associated exclusively with GISTs and may provide a basis for further investigation into the role of DOG1 in canine malignancy.

The remaining patient had an unresectable tumor and received tyrosine kinase inhibitor therapy; however, sequential treatment with imatinib and sunitinib was clinically ineffective. However, their clinical behavior differs: D842Y-mutant GISTs consistently present as large, hypervascular tumors associated with acute complications. The therapeutic efficacy of tyrosine kinase inhibitors remains unclear, underscoring the need for further case accumulation to better define the clinical course and determine optimal treatment strategies for this rare subtype.

After multidisciplinary discussion, pancreaticoduodenectomy and tyrosine kinase inhibitor therapy were proposed, but the patient declined and has been managed conservatively with close follow-up and symptomatic improvement. In this patient, the pancreatic mass mimicked a NET on imaging and was ultimately identified as an extragastrointestinal stromal tumor (GIST), underscoring the importance of histopathologic and immunohistochemical confirmation when evaluating hypervascular pancreatic lesions.

Surgical excision remains the mainstay of management. This case highlights a rare, complex presentation of gastroduodenal intussusception with biliary obstruction due to a gastric GIST.