A 77-year-old male presented with abdominal distension and pitting edema of both lower limbs for 1 month. He had no complaints of respiratory symptoms, such as a cough, sputum, dyspnea, and no history of fever or chills. On examination, his abdomen was soft and distended, with shifting dullness on percussion, and decreased breath sounds were detected in the right lower lung field, without audible crackles or wheezes on auscultation. He had grade 2 pitting edema of both lower extremities, and there was no evidence of hepatosplenomegaly or enlargement of superficial lymph nodes. The hemogram was unremarkable, although the serum lactate dehydrogenase (LDH) level was elevated to 393 IU/L (reference range, 100 to 225 IU/L). The chest X-ray showed a large right-sided pleural effusion, and electrocardiogram and thyroid function tests were normal.
Both thoracentesis and paracentesis were performed. The pleural effusion contained 5,750/muL of red blood cells (RBCs) and 2,990/muL of white blood cells (WBCs). In the differential cell count, 82% of the WBCs in the routine cell count had an atypical morphology. The results of the chemical analysis of the pleural effusion were as follows: protein 3,833 mg/dL, glucose 13 mg/dL, LDH 6,000 IU/L, and adenosine deaminase 310 IU/L. The acid-fast bacilli smear and culture and real-time nested polymerase chain reaction for Mycobacterium tuberculosis complex DNA in both the pleural effusion and sputum showed negative results. No microorganisms were identified on Gram stain and from bacterial culture. Ascites contained 200/muL of RBCs and 10,880/muL of WBCs with 33% lymphocytes and 67% atypical cells. Results of chemical analysis showed a total protein of 3,908.9 mg/dL, albumin of 2,400 mg/dL, glucose of 34 mg/dL, and LDH of 3,476 IU/L. The serum-ascites albumin-gradient was 0.8 g/dL, and the Gram stain and bacterial cultures were negative.
The cytological evaluation of both the pleural effusion and ascites demonstrated numerous large and pleomorphic cells with eosinophilic macronucleoli and abundant cytoplasm, with an immunoblastic or anaplastic appearance (Fig. 1A-C). Tumor markers, including prostate-specific antigen (PSA), carcinoembryonic antigen, and carbohydrate antigen 19-9 were assessed in order to clarify the origin of the malignant effusion. Esophagogastroduodenoscopy (EGD), colonoscopy (CS), computed tomography (CT) of the chest, abdomen, and pelvis, whole body positron emission tomography-computed tomography (PET-CT), and bone scan were performed. The serum PSA level was increased to 7.713, while other tumor markers were within the normal range. EGD and CS detected some tubular adenomatous polyps, which were confirmed as benign. CT scans showed a large pleural effusion, contrast enhancement of the peritoneum, and prostatic enlargement (Fig. 2A). Therefore, a percutaneous drainage catheter was inserted into the chest, and a prostate biopsy was performed, which confirmed that the prostate tissue was benign. Diffuse hypermetabolism along the omental and peritoneal infiltration was detected on the PET-CT scan (Fig. 2B), and no significant abnormal uptake was detected on the bone scan.
On immunocytochemistry, the neoplastic cells in the pleural effusion were CD45-positive and cytokeratin-negative, and the tumor cells were positive for CD20 and MUM-1 with weak-to-moderate intensity and negative for CD138, CD79a, CD3, Bcl-2, Bcl-6, and HHV8. The Ki-67 proliferating index was approximately 90%. Epstein-Barr virus (EBV)-encoded small RNAs in situ hybridization showed no EBV-infected cells (Fig. 1D-I).
Serological tests were negative for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) and positive for anti-hepatitis B surface antibody with a titer of 141.2 IU/L, consistent with a history of HBV vaccination. Bone marrow examination detected hypocellular marrow (cellularity of 21%-30%) without evidence of lymphoma involvement, and cytogenetic examination detected a normal karyotype: 46,XY.
Based on the results described above, the patient was diagnosed with PEL-LL without concurrent HCV, HBV, or HIV infection. Six cycles of R-CHOP chemotherapy with symptomatic improvement was administered following the completion of therapy. The CT scan showed almost complete resolution of the pleural effusion and ascites with a decrease in the omental infiltration and peritoneal thickening with no metabolic activity on the PET-CT (Fig. 2C and D). The patient has been in a progression-free state for 15 months.