S3038 Peri-Gastric Venous Hemangioma: A Tale of Discordant Cytology and Histology on EUS-Core Biopsy

Abstract

INTRODUCTION: Hemangiomas are highly vascular tumors, without known malignant potential. They are extremely rare to arise from the upper gastrointestinal (GI) tract and may present with variable symptoms. Due to low sensitivity of radiological imaging, their diagnosis in the GI tract is often challenging. We present a case of a peri-gastric hemangioma adequately diagnosed with endoscopic ultrasound (EUS)-guided biopsy. CASE DESCRIPTION/METHODS: A 48-year old lady with hypertension and diabetes mellitus, sought care for a 3-month history of left upper quadrant (LUQ) abdominal pain, with normal hemoglobin and comprehensive metabolic panel. Abdominal computed tomography (CT) demonstrated a 7cm lobulated, exophytic LUQ mass suspected to be arising externally from the stomach, raising suspicion for gastrointestinal stromal tumor (GIST). She was referred to us for EUS, which revealed a 8.9 × 5.5 cm heterogeneously hypoechoic, irregularly marginated mass, thought to be exophytic and abutting the proximal portion of the stomach. Core biopsies were obtained, and sent for both cytology (in CytoLyt) and histology (in Formalin). The cytology showed proliferation of bland spindle cells concerning for spindle cell neoplasm, however, the histology demonstrated abnormal venous structures with prominent spindle cell smooth muscle walls and luminal CD34 + endothelial cells supporting the diagnosis of benign venous hemangioma. The patient remained symptomatic with LUQ discomfort and underwent surgical resection. Final post-operative pathology confirmed the diagnosis of venous hemangioma. DISCUSSION: Contrast has higher specific gravity than blood and there is slow blood flow within hemangiomas; therefore, radiographic imaging may be inconclusive as hemangiomas may appear as non-specific heterogeneous lesions. EUS can determine the anatomy of the lesion, its origin and vascularity. Tissue biopsies are challenging due to the high vascularity of these lesions and their submucosal location, but histology can provide a definitive diagnosis. A few cases of endoscopic resection of intraluminal small venous and cavernous hemangiomas have been reported, but surgical resection is the most common treatment modality for symptomatic extra-luminal GI tract venous hemangiomas. Our case educates endoscopists that histopathological evaluation with immunohistochemistry staining is more accurate than cytological analysis for diagnosis of venous hemangiomas, and hence core sample should be sent in formalin rather than for cytology alone.Figure 1.: Histology of a peri-gastric mass showing (A) abnormal venous structures with prominent spindled smooth muscle walls and luminal CD34 positive benign endothelial cells (inset). The lesion signed out as venous hemangioma. Concurrent cytology (B) showed proliferation of bland spindle cells raising concern for spindle cell neoplasm.