Eosinophilic solid cystic renal cell carcinoma: A series of 3 cases elucidating the spectrum of morphological and clinical features of an emerging new entity

Abstract

Eosinophilic solid cystic renal cell carcinoma (ESC-RCC) is a recently described entity, which demonstrates distinct clinical, pathological and molecular features. We present a series of three cases, the first to be reported from the Indian subcontinent. All three patients were over 50 years of age; and presented with a large kidney mass. One patient had a locally advanced disease while the other two presented with metastases. Microscopic examination revealed a tumor displaying solid-cystic and/or papillary areas composed of clear as well as eosinophilic cells in all three cases. On immunohistochemistry, all the three cases showed a unique CK20+/α-methyl-acyl-CoA-racemase + immunophenotype. Melan-A was focally positive in Case 2. Cytokeratin 7 was focally but strongly positive in Case 3. The two patients with metastatic disease were diagnosed on core biopsies and were advised oral tyrosine kinase inhibitor therapy. The third patient underwent upfront radical nephrectomy. Due to its peculiar morphology and immunoprofile, the diagnosis of ESC-RCC can be confidently made even on a core biopsy. Most cases reported till date had an indolent course. The metastatic presentation in two of our patients emphasizes the need to gather further evidence to ascertain the biological behavior of this emerging entity.

FDG PET/CT in Eosinophilic Solid and Cystic Renal Cell Carcinoma With Lung Metastases

“…They may manifest as solid, mixed solid-cystic, or cystic lesions, depending on the proportion of the solid and cystic components. [6][7][8][9] Sakhadeo et al 6 reported a case of high-grade eosinophilic solid and cystic renal cell carcinoma with lymph node and bone metastases showing intense FDG uptake as was observed in our case. Tong et al 7 reported a case of eosinophilic solid and cystic renal cell carcinoma in bilateral kidney showing no significant FDG uptake, but increased 99m Tc-MIBI uptake mimicking oncocytoma or lipid-poor angiomyolipoma.…”

“…There are currently limited data regarding the imaging features of eosinophilic solid and cystic renal cell carcinoma. They may manifest as solid, mixed solid-cystic, or cystic lesions, depending on the proportion of the solid and cystic components 6–9 . Sakhadeo et al 6 reported a case of high-grade eosinophilic solid and cystic renal cell carcinoma with lymph node and bone metastases showing intense FDG uptake as was observed in our case.…”

“…Rare cases have been documented with locally advanced disease or distant metastases. [4][5][6] The tumors are typically solitary and rarely multifocal. 4,7 There are currently limited data regarding the imaging features of eosinophilic solid and cystic renal cell carcinoma.…”

“…The great majority of the tumors show indolent behavior. Rare cases have been documented with locally advanced disease or distant metastases [4][5][6]. The tumors are typically solitary and rarely multifocal 4,7.…”

Update on Selected Oncocytic Renal Cell Tumors

“…7,8 Subsequently, ESC-RCC also has been reported in younger individuals and males. 25,31,50,51 ESC-RCC is considered to be the sporadic counterpart to the third subtype (RCC with an eosinophilic cytoplasm as well as a solid and cystic growth pattern) of TSC-associated RCC. [52][53] The great majority of ESC-RCCs are sporadic, with approximately 10% occurring in patients with TSC.…”