Urothelial Cancer With Occult Bone Marrow Metastases and Isolated Thrombocytopenia

Bladder cancer rarely presents clinically with a myelophthisic picture from diffuse bone marrow infiltration especially in the absence of detectable skeletal metastases. A 75-year old man presented with newly diagnosed urothelial cell carcinoma of the bladder. Pathology from transurethral resection of bladder tumor demonstrated muscle-invasive disease. Pre-therapy imaging including CT abdomen/pelvis, CXR and bone scan demonstrated liver lesions concerning for metastatic disease but no skeletal metastases. Labs were notable for isolated thrombocytopenia, hypercalcemia and acute kidney injury prompting hospitalization. Hematologic work-up including bone marrow aspiration and biopsy revealed diffuse infiltration of the bone marrow by urothelial cancer. The case illustrates the importance of fully investigating otherwise unexplained clinical findings in patients with clinically localized urothelial cancer prior to curative intent surgery.