Abstract
BACKGROUND: Plasma cell myeloma (PCM) is characterized by hypercalcemia, renal impairment, anemia, and bone destruction. While pleural effusion, ascites, abdominal pain, and bloody stool are common manifestations of lung disease or gastrointestinal disorders, they are rarely observed in patients with PCM. CASE SUMMARY: A 66-year-old woman presented with complaints of recurrent chest tightness, wheezing, and abdominal bloating accompanied by bloody stools. Computed tomography revealed pleural effusion and ascites. Pleural effusion tests showed inflammation, but the T-cell spot test and carcinoembryonic antigen were negative. Endoscopy showed colonic mucosal edema with ulcer formation and local intestinal lumen stenosis. Echocardiography revealed enlarged atria and reduced left ventricular systolic function. The diagnosis remained unclear. Further testing revealed elevated blood light chain lambda and urine immunoglobulin levels. Blood immunofixation electrophoresis was positive for immunoglobulin G lambda type. Smear cytology of the bone marrow showed a high proportion of plasma cells, accounting for about 4.5%. Histopathological examination of the bone marrow suggested PCM. Flow cytometry showed abnormal plasma cells with strong expression of CD38, CD138, cLambda, CD28, CD200, and CD117. Fluorescence in situ hybridization gene testing of the bone marrow suggested 1q21 gene amplification, but cytogenetic testing showed no clonal abnormalities. Colonic mucosa and bone marrow biopsy tissues were negative for Highman Congo red staining. The patient was finally diagnosed with PCM. CONCLUSION: A diagnosis of PCM should be considered in older patients with pleural effusion, ascites, and multi-organ injury.