Multifocal Gastric Histiocytic Sarcoma Presenting as Gastrointestinal Bleeding

Abstract

Histiocytic sarcoma is a rare malignancy that accounts for less than 1% of hematologic neoplasms, and shows morphologic and immunophenotypic non-Langerhans histiocytic differentiation. Commonly presents with nodal involvement, however extranodal sites are involved in 1/2 of cases. The skin and gastrointestinal (GI) tract are commonly involved. GI involvement manifests as abdominal mass, pain, intestinal obstruction, lower GI bleeding, or weight loss. We present case of histiocytic sarcoma manifesting as upper GI bleeding from innumerable synchronous gastric polyps. A 76 y/o female with CAD requiring multiple coronary stents, CABG, and AICD on dual antiplatelet therapy presented with melena and hematemesis. EGD revealed innumerable sessile and pedunculated polyps in the gastric body, fundus, and antrum. Two oozing polyps up to 5.3cm in diameter required polypectomy. Pathology showed histiocytic sarcoma. CT-scan was negative for metastases. 4 days post-discharge she developed further GI bleeding that required total gastrectomy with Roux-en-Y reconstruction for hemostasis. Intra-operatively no metastases were seen and negative margins were obtained. Two months later, the patient had recurrent hematemesis. CT scan showed small bowel obstruction and an intraluminal lesion, confirmed to be recurrent histiocytic sarcoma on endoscopic biopsies. The patient was discharged with plans for outpatient treatment, but sadly expired one month later. Although histiocytic sarcoma has been described throughout the GI tract, tumor confined to the stomach has only been described in 10 cases. Upon literature review, these have been mainly described in Asian populations and associated with H. pylori infection. Histiocytic sarcoma may present as a unifocal or multifocal tumor. Disease course is difficult to predict due to scarcity of reports, but aggressive behavior has been described. Our case illustrates the propensity for multifocal histiocytic sarcoma to behave aggressively despite complete resection with negative margins. Despite complete resection, distal recurrence has been described in 50% of cases and local recurrence in 20% of the cases. Multifocal disease confers a poor prognosis and is associated with poor response to chemotherapy. Our case represents an unusual case of multifocal disease limited to one organ. Complete margin-negative resection was possible, but the tumor recurred regionally in the jejunum, reflecting propensity to recur distantly rather than locally.Figure. 56: mm oozing pedunculated polyp seen on proximal gastric body on EGD at initial presentation.Figure: Innumerable gastric polyps throughout the fundus and body of the stomach.Figure: Jejunal polyp representing recurrence after margin negative total resection with gastrectomy.