Extraskeletal Ewing Sarcoma of the Gastrointestinal and Hepatobiliary Tract: Deceptive Immunophenotype Commonly Leads to Misdiagnosis.

Ewing sarcoma (ES) is an uncommon mesenchymal neoplasm that typically develops as a bone mass, although up to 30% arise in extraskeletal sites. ES of the gastrointestinal (GI) and hepatobiliary tract is rare and may be misdiagnosed as other, more common neoplasms that occur in these sites. However, the correct classification of extraskeletal ES is important for timely clinical management and prognostication. We reviewed our experience of ES in the GI and hepatobiliary tract in order to further highlight the clinicopathologic features of these neoplasms and document the potential for misdiagnosis in this setting. The archives and consultation files of 6 academic institutions were retrospectively queried for cases of ES occurring in the GI and hepatobiliary tract. The histologic slides and ancillary studies were reviewed and clinical data were retrieved for each case through the electronic medical records, when available. Twenty-three patients with ES in the GI and/or hepatobiliary tract were identified from 2000 to 2022. Of these, 11 were women and 12 were men with a median age of 38 years (range, 2 to 64). Tumor locations included the pancreas (n=5), liver (n=2), stomach (n=3), colorectum (n=3), and small intestine (n=5), as well as tumors involving multiple organs, pelvis and retroperitoneum (n=5). Tumor size varied between 2 cm and 18 cm. Twenty were primary and 3 were metastases. Of the 23 cases, only 17% were initially diagnosed as ES. The most common misdiagnoses involved various forms of neuroendocrine neoplasia due to expression of synaptophysin and other neuroendocrine markers (22%). A wide variety of diagnoses including GI stromal tumor was considered due to aberrant CD117 expression (4%). The diagnosis of ES was ultimately confirmed by detection of the EWSR1 rearrangement in 22 cases. The remaining case was diagnosed using traditional immunohistochemistry. Follow-up information was available in 20 cases, with follow-up time varying between 2 and 256 months. Six patients with follow-up died of disease between 6 and 60 months following initial presentation. Our data indicate ES in the GI and hepatobiliary tract is commonly misdiagnosed leading to a delay in therapy. In light of the attendant therapeutic and prognostic implications, ES should be considered in the differential diagnosis of any GI or hepatobiliary tumor with epithelioid and/or small round cell morphology.

First Recurrence of Synovial Sarcoma Presenting With Solitary Pancreatic Mass.

Synovial sarcoma usually presents in the lower extremities and metastasizes to the lungs; however, unusual patterns of recurrence can occur. For patients with recurrent synovial sarcoma to a proximal peripancreatic lymph node, a pancreaticoduodenectomy or Whipple procedure is the best option for a cure. Lymph node metastasis from synovial sarcoma is exceptionally rare, and data guiding the use of the Whipple procedure for curative resection of metastatic synovial sarcoma are even more sparse. In this report, we describe the management of a patient with metastatic synovial sarcoma to a proximal peripancreatic lymph node with a pancreaticoduodenectomy.

Surgical resection of leiomyosarcoma of the inferior vena cava: A case series and literature review.

OBJECTIVES: We review our institution's experience in treating leiomyosarcomas involving the inferior vena cava, and we offer guidance on the management. METHODS: A text-based search was performed to identify all patients who underwent surgical resection between January 2002 and October 2020. Clinicopathologic data, intraoperative variables, and outcomes were extracted from chart review. RESULTS: Twelve of 16 patients (75%) had localized disease; the remaining had limited metastatic disease. Seven of 16 patients (44%) received neoadjuvant chemotherapy or radiation; three patients had partial responses, and four patients had stable disease using RECIST 1.1 criteria. IVC reconstruction was performed in 14 of 16 patients (88%); IVC was ligated for the remaining two patients. Half of all patients had R0 resection on final pathology; the remaining had R1 resections. Progression-free survival (PFS) and overall survival (OS) were not statistically different between patients with R0 and R1 resection. Median PFS was 1.8 years (95% CI 0.89 - not reached); median OS was 6.5 years (1.8 - not reached). Only one patient (6%) experienced local disease recurrence; 4 of 16 patients (25%) experienced disease recurrence distally without local recurrence. CONCLUSIONS: Resection of IVC leiomyosarcomas at a sarcoma referral center with experience in vascular reconstruction can lead to many years of recurrence-free survival. Surgical resection should be offered to patients with a low volume of metastatic disease to reduce local complications from the primary tumor, many of which exert significant mass effect on surrounding organs. For patients with metastatic disease or large, high-risk tumors, neoadjuvant chemotherapy can provide a biologic test of disease stability prior to resection.

Evidence for a 'preinvasive' variant of fungal sinusitis: Tissue invasion without angioinvasion.

Clinical experience has suggested the existence of an intermediate form of fungal sinusitis between the categories of non-invasive fungal sinusitis (non-IFS) and invasive fungal sinusitis (IFS). This fungal sinusitis variant demonstrates unhealthy mucosa by endoscopy with fungal invasion, but lacks angioinvasion microscopically, representing what clinically behaves as a 'pre-invasive' subtype of fungal sinusitis. Unlike non-IFS disease, patients with pre-invasive fungal sinusitis were still felt to require anti-fungal medications due to histologic presence of invasive fungus. While sharing some clinical features of IFS, these 'intermediate' patients were successfully spared extended and repeated surgical debridements given the microscopic findings, and have been successfully treated with shorter courses of antifungal therapy. These select patients have had favorable outcomes when managed in a judicious and semi-aggressive manner, in an undefined zone between the treatments for routine fungal ball and aggressive IFS.