Anaplastic large cell lymphoma (ALCL) is a rare and unfortunately aggressive lymphohematopoietic malignancy. While it can affect a number of extranodal sites, genitourinary involvement is extremely uncommon, with only eleven reported cases in the literature. Here, we report a case study of a healthy 50-year-old male with no prior urologic history, presenting with chief complaint of gross hematuria. Non-contrast CT imaging demonstrated irregular contours within the bladder with mild hydronephrosis bilaterally, regional lymphadenopathy, and a lytic bone lesion, concerning for malignancy. The patient was taken for cystoscopy, and biopsies were obtained from what was immediately apparent to be a grossly invasive tumor. His hospital course was further complicated by acute-on-chronic renal failure in the setting of stable, non-obstructing hydronephrosis, requiring placement of bilateral nephrostomy tubes. Ultimately, a pathologic diagnosis of anaplastic lymphoma kinase (ALK)negative ALCL was made, which is notably one of eleven cases of ALCL with primary bladder involvement and only the second of these cases that is ALK-negative. 
 
Keywords: Anaplastic; Lymphoma; Bladder; Malignancy