The lesion was biopsied.

Pathology:

The sections show features of metastatic poorly differentiated carcinoma, invading in-between the bony trabeculae.

The tumor forms nests, surrounded by desmoplastic stroma. The tumor cells have enlarged nuclei, prominent nucleoli and moderate amounts of eosinophilic cytoplasm. No evidence of lymphovascular invasion is seen.

The tumor morphology is similar to that seen in the previous bladder biopsy

Diagnosis: Left tibial bone bx: Metastatic poorly differentiated carcinoma, consistent with bladder primary.