A 53-year-old woman with on and off complaints of dysuria, urgency, urge incontinence, and increased frequency of urination presented to the urology department of our institute. There was long-standing history of recurrent cystitis, but no history of hematuria or loin pain.
On examination, there was no organomegaly or lymphadenopathy. Urine examination showed the presence of numerous pus cells, but on culture was sterile, signifying sterile pyuria. Urine cytology for malignant cells was negative. Routine hematological investigation, screening renal and liver function tests were normal except for mildly raised total count at 11,800 cells/cu mm. Peripheral blood smear examination was normal. The patient was hypothyroid. Ultrasound, computerized tomography (CT), and intravenous urography showed diffuse thickening of the bladder wall [Figure 1a and b]. Cystoscopy showed a smooth nonulcerated nodular bulge in the right side of the bladder wall [Figure 2]. Ziehl-Neelsen (ZN) stain of the urine showed the presence of acid-fast Bacilli (AFB). Based on the clinical presentation, imaging, a preliminary AFB positivity report, and due to the exceptionally high incidence of tuberculosis (TB) in this region, the patient was started on antitubercular treatment. Initially, the patient appeared to improve symptomatically. In the meantime, simultaneously sent urine sample for culture and polymerase chain reaction could not confirm the presence of mycobacterium TB. Furthermore, repeat samples of urine examined on microscopy did not reveal the presence of AFB.
On recurrence of the symptoms, a repeat cystoscopy was performed, and the findings were similar to the pretreatment cystoscopy with thickening of the bladder mucosa. Hence, a bladder biopsy was planned, and transurethral resection was performed. Tissue was also taken from the deep muscle. Histopathological examination (HPE) showed intact but thinned out bladder epithelium. The subepithelial tissue showed the presence of lymphoid follicles with expanded marginal zone, which totally replaced the sub epithelial bladder tissue. The cells were small to medium sized with dispersed chromatin, inconspicuous nucleoli and abundant cytoplasm showing clearing, imparting monocytoid morphology. No large or transformed cells were seen. No granuloma was identified. On immunohistochemistry (IHC), the cells stained positive for CD45 and CD20 [Figure 3]. Cytokeratin, epithelial membrane antigen (EMA), CD3, CD5, CD10, and Bcl2 were negative. ZN stain was negative for AFB on the HPE sections. Deep muscle biopsy showed presence of lymphoid follicles with reactive germinal center. CT scan failed to reveal any lymphadenopathy or involvement of any other organ. Bone marrow examination was unremarkable.
Based on these findings, a diagnosis of primary MALT lymphoma of the bladder was made, Ann-Arbor stage 1EA. The patient was started on systemic chemotherapy with cyclophosphamide, vincristine, doxorubicin, and prednisolone. Six cycles were given. The patient is under follow-up and 9 months postchemotherapy, the patient is symptomatically normal. Repeat CT scan, cystoscopy, and postchemotherapy showed completely normal bladder [Figure 4].