Triceps mass - A rare presentation of renal cell carcinoma.

Renal cell carcinoma (RCC) can commonly metastasize to the liver, lungs, bones and brain. We herein report a rare presentation of oligometastatic RCC with isolated synchronous metastasis to the triceps. A 44-year-old male presented with an enlarging mass involving the right triceps. A biopsy revealed features consistent with metastatic clear cell RCC (ccRCC). Subsequent computed tomography (CT) Imaging demonstrated a 6 cm right renal mass. He underwent a right laparoscopic radical nephrectomy which revealed a tumour stage 1b ISUP Grade 2 ccRCC. Clinicians should have a degree of suspicion for a metastatic lesion for an enlarging soft tissue mass.

Ultrastructural identification of a proximal tubulopathy without crystals in a relapsed multiple myeloma patient.

A multiple myeloma patient, who had been treated with a hematopoietic stem cell transplant, underwent a renal biopsy for investigation of a possible relapse of disease as indicated by increased serum creatinine and positive urinary Bence-Jones protein containing increased kappa light chain. Paraprotein-related renal disease was not evident by light microscopy or immunofluorescence microscopy however electron microscopy demonstrated a proximal tubulopathy with intracytoplasmic non-crystalline inclusions. The ultrastructural findings suggested possible end-organ involvement by the disease and follow-up studies subsequently revealed a relapsed multiple myeloma in the patient. The case exemplifies the usefulness of electron microscopy in detecting paraproteins that, in some instances, may be difficult to demonstrate by other techniques.