Gamna-Gandy bodies in renal neoplasms: A multi-institutional clinicopathologic study of 350 consecutive nephrectomies.

Gamna-Gandy (GG) bodies are sclerosiderotic nodules composed of iron pigment and calcium, that have been described predominantly in the spleens of patients with sickle cell disease. Their formal depiction in the kidney is mainly limited to case reports and small series. We aimed to investigate the incidence of GG bodies and associated clinicopathologic features in consecutive nephrectomies performed for renal tumors. Slides of consecutive nephrectomies for renal neoplasms at 3 institutions were reviewed by genitourinary pathologists, with detailed clinicopathologic features recorded. The incidence of GG bodies in our nephrectomy cohort was 13% (44/350). The most common tumor exhibiting GG bodies was clear cell renal cell carcinoma (RCC) (40/44), followed by papillary RCC (2/44), chromophobe RCC (1/44), and epithelioid angiomyolipoma (1/44). Most RCCs were pathologic stage pT3a (46%). GG bodies were intratumoral in 77%, peritumoral in 5%, and both in 18% of patients. They were focal in 43% and multifocal in 57%, with the largest focus ranging from 0.2 to 7 mm (mean 1.7 mm). Background fibrosis and hemosiderin laden macrophages were commonly associated (93% for both). All tumors demonstrated cystic elements. In 2 renal tumor specimens, an extensive fungal workup was performed and was negative; the "structures" were not formally recognized as GG bodies in either specimen. GG bodies are not an uncommon finding in renal tumors, particularly in clear cell RCC. Awareness of the morphologic appearance is crucial to avoid mistaking them for fungal structures or other organisms.