Histoplasma colonization of metastatic renal cell carcinoma (RCC) cells in a case of adrenal histoplasmosis involved by metastatic eosinophilic solid cystic RCC with rhabdoid differentiation

ABSTRACT

A 58-year-old male presented with frank hematuria for three months and underwent radical nephrectomy outside, as a renal mass was detected on ultrasound involving the lower pole of the left kidney. The case was diagnosed as eosinophilic solid cystic renal cell carcinoma (RCC), WHO grade 4, with ipsilateral adrenal metastasis, but the adrenal gland additionally showed the presence of coexisting histoplasmosis. Interestingly, histoplasma colonization was found within metastatic RCC cells, which is hitherto unreported in existing literature. Rhabdoid differentiation of this tumor, a novel entity recently introduced in recent WHO classification, is again very unusual; there is a chance that the fungal organisms may have played a role in this phenomenon. The patient is currently under close follow-up after completing a systemic antifungal regimen.