Primary Gastric Hodgkin's Lymphoma: An Extremely Rare Entity and A Diagnostic Challenge.

A 71-year-old man was admitted to Stanford University Hospital with a 1-year history of poor appetite, 20 lbs weight loss, and recent episodes of hematemesis. He did not complain of abdominal pain, dysphagia, odynophagia, fever, or chills. His past medical history was significant for hypertension and gastro-esophageal reflux disease. The family and social history were unremarkable. Physical examination revealed a thin male with normal vital signs. There was no peripheral lymphadenopathy, and examination of the abdomen was unremarkable, with no enlargement of the liver or spleen or ascites. Laboratory investigations revealed iron deficiency anemia with a hemoglobin of 7.5 g/dL, WBC of 7,100/lL, and platelet count of 365,000/lL. His serum electrolytes and liver function tests were normal. Blood transfusion was declined due to religious beliefs. He was treated with intravenous iron and erythropoietin. An upper gastrointestinal endoscopy revealed a large fungating mass (*4.5 cm in maximum diameter) (Fig. 1), involving the gastric fundus and cardia, which on histological examination revealed only atypical cells without clear evidence of malignancy. Colonoscopy was normal; a CT of his chest, abdomen, and pelvis documented thickening of the gastric wall, consistent with his known gastric mass. There was no evidence of pathological lymphadenopathy or local, regional, or distant metastases. Due to the lack of a clear pathological diagnosis, upper gastrointestinal endoscopy was repeated. Histological examination of gastric biopsies again revealed only ulceration and necrosis with only one biopsy sample positive for atypical cells. Pan-cytokeratin immunostaining was negative for infiltrating epithelial cells, while no increase in B cells was apparent with CD20 immunostaining. Urease testing for Helicobacter pylori was negative. An endoscopic ultrasound (EUS) confirmed an irregular mass with poorly defined borders and heterogeneous echogenicity, 29 9 30 mm in maximal cross-sectional diameter (Figs. 2, 3). There was sonographic evidence suggesting invasion into the serosa. Fine needle aspiration (FNA) was performed. Cytologic examination again reported atypia. A clear pathological diagnosis remained elusive. Given the high suspicion for malignancy, the patient underwent yet another upper endoscopy during which deep ‘‘jumbo’’ forceps biopsies of the mass were obtained. Histological examination on this occasion revealed ulcerated mucosa with an underlying mixed inflammatory infiltrate, including lymphocytes, plasma cells, and eosinophils. Against this background were scattered atypical cells with large nuclei and prominent nucleoli. Rare bi-lobed cells resembling Reed–Sternberg cells were also observed (Figs. 4, 5). The large cell population expressed CD30 and CD15 (Figs. 6, 7). Faint nuclear staining was present for PAX-5; in situ hybridization with the Epstein–Barr virus-encoded RNAs (EBER-1) as a probe for Epstein–Barr virus (EBV) S. Sethi S. Banerjee (&) Division of Gastroenterology and Hepatology, Stanford University, Stanford, CA, USA e-mail: sbanerje@stanford.edu