86-year-old man with a history of hypertension and type 2 diabetes mellitus had been treated for end stage kidney disease with continuous cycling peritoneal dialysis since February 2017. He presented to the home dialysis unit complaining of difficulties with initial drain alarms on his cycler for the last 2 nights and "whitish" dialysate. He denied abdominal pain or constitutional symptoms aside from weight loss associated with resolution of peripheral edema. He did not have any previous episodes of peritonitis or history of TB contact. His examination was unremarkable including normal vital signs and lack of abdominal tenderness.
As per out unit peritonitis protocol, 1L of 2.5% Dianeal was allowed to dwell for 2 hours and the effluent was sent for analysis including cell count, differential, bacterial, and mycobacterial cultures. Given the "milky" appearance of the fluid, triglycerides were also ordered. He received empiric intraperitoneal antibiotics including ceftazidime and vancomycin. Total nucleated cell count was 354 * 106/L with 87% lymphocytes, 8% monocytes, and 3% neutrophils. Cultures were negative. Triglyceride (TG) concentration was 6.3 mmol/L (557 mg/dl). Based on the elevated TG concentration he underwent a CT scan with contrast of the abdomen and a second dialysate sample was sent for cell count, TG, cytology, and flow cytometry (the dialysate was no longer cloudy). He was found to have a mildly enlarged spleen and multiple enlarged lymph nodes in the mesentery, retroperitoneum, and inguinal regions including a cluster of enlarged nodes forming a conglomerate retroperitoneal mass suggestive of lymphoma. There was a moderate increase in density of the mesentery, possibly on the basis of lymphatic obstruction. His total nucleated cell count remained elevated at 420 with 96% lymphocytes; TG concentration was only 0.21 mmol/L. Cytology was negative for malignant cells. Flow cytometry of the dialysate showed predominately monotypic B cells with lambda light chain restriction that coexpressed CD20 and CD19 but lacked CD5 and CD10 suggestive of a monoclonal lymphoid process. An inguinal lymph node biopsy revealed predominant diffuse to nodular pattern of small monotonous lymphocytes, suggestive of B cell lymphoma. Immunohistochemical stain was positive for CD20 (diffuse), BCL2 (diffuse), and few remaining CD21 (FDC). It was negative for CD3, CD5, CD10, CD23, and C43. Kappa and lambda stains were nonspecific. Ki67 proliferation index was less than 5%. Final diagnosis was monoclonal B cell lymphoproliferative disorder, likely of low grade. He is being followed by the malignant hematology team, with no active treatment. From a PD perspective, the patient had no further episodes of chylous ascites and remains on CCPD.