Sarcomatoid renal cell carcinoma presenting with cannonball pulmonary metastases

A woman in her 30s without prior medical history presented with 4 months of progressive back pain that evolved to paraplegia, followed by dyspnoea and haemoptysis. Imaging revealed numerous, well-circumscribed pulmonary nodules consistent with cannonball metastases, a loculated right pleural effusion, bilateral renal masses, pancreatic nodules and osteolytic L5 collapse with cord compression. The lung lesion biopsy demonstrated a poorly differentiated neoplasm, which on immunohistochemistry was most consistent with metastatic sarcomatoid carcinoma of renal origin. She required intubation, pleural drainage and high-dose dexamethasone, achieving partial neurological recovery, and subsequently received palliative spinal radiotherapy. Sarcomatoid renal cell carcinoma is a rare, aggressive variant with rapid progression and poor prognosis. Immune checkpoint inhibitors, alone or combined with vascular endothelial growth factor-targeted agents, are current standard therapy, but access may be restricted in resource-limited settings. Although the cannonball pattern can suggest renal or other hypervascular primaries, a comprehensive imaging and histological evaluation remains essential for diagnosis.