PERİTONEAL PLASMA CELL NEOPLASM MIMICKING TUBERCULOUS PERITONITIS AND COMPLICATED BY COLONİC PERFORATION

Abstract

Case: A 53-year-old man with diabetes mellitus, hypertension, and end-stage renal disease on hemodialysis presented with abdominal pain, bloating, and diarrhea. Abdominal computed tomography demonstrated massive ascites, diffuse peritoneal thickening, and lymphadenopathies. Ascitic fluid analysis revealed low-SAAG lymphocyte-predominant exudative ascites with markedly elevated ADA and low glucose levels, strongly mimicking tuberculous peritonitis. However, microbiological studies were negative, and diagnostic laparoscopy with peritoneal biopsy demonstrated plasma cell neoplasia with lambda light-chain restriction. During follow-up, the patient developed spontaneous colonic perforation requiring emergency surgery. Histopathological examination of the colectomy specimen revealed diffuse plasma cell infiltration involving the bowel wall with transmural ischemic necrosis. The patient died postoperatively. This case highlights the diagnostic challenge of peritoneal plasma cell neoplasms, which may mimic tuberculous peritonitis clinically, radiologically, and biochemically, including markedly elevated ascitic ADA levels. Additionally, spontaneous colonic perforation due to bowel-wall plasma cell infiltration appears to be exceedingly rare.