18F-FDG PET/CT and 99mTc-MIBI SPECT/CT Findings in a Patient With Eosinophilic Solid and Cystic Renal Cell Carcinoma

Analysis of Imaging and Pathologic Features in Eosinophilic Solid and Cystic Renal Cell Carcinoma

OBJECTIVE

Eosinophilic solid and cystic renal cell carcinoma (ESC-RCC) is rare and difficult to diagnose. Therefore, we aim to investigate the imaging and pathologic features of ESC-RCC.

METHODS

Fifteen cases of ESC-RCC with pathologically confirmed diagnoses were retrospectively collected: CT was performed in 15 cases and MRI in 9 cases.

RESULTS

In these patients (6 males and 9 females) (age: mean, 53.3 ± 14.7 years; range, 27-72 years), all tumors were unilateral, renal, and solitary with no clinical symptoms and were classified into-type 1: cystic-solid component, with equal cystic and solid components, was the most common (8/15, 53.3%); type 2: predominantly cystic with a small solid component (4/15, 26.7%); and type 3: predominantly solid (3/15, 20%). The solid component showed equal/slightly higher density on the CT-plain-scan, equal/slightly high signal on the T1-weighted image (T1WI), and low signal on the T2-weighted image (T2WI). Ten cases showed progressive enhancement, while 5 showed a fast-wash-in and fast-wash-out enhancement. One patient experienced hemorrhage, while the others showed no signs of hemorrhage, necrosis, fat, or calcification. Pathologically, the tumor showed cystic solidity, with eosinophilic cytoplasm and granular basophilic-colored spots with focal or diffuse expression of CK20. Ten patients had componential nephrectomy and 5 had radical nephrectomy. No recurrence or metastasis was noted in any case at the follow-up (8-49 months).

CONCLUSION

This study describes the imaging and pathologic features of a rare type of renal cancer and proposes 3 imaging types to enhance physicians' diagnosis of this disease and guide clinical diagnosis and treatment.

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

ABSTRACT

Eosinophilic solid and cystic renal cell carcinoma is a recently described emerging renal tumor. Usefulness of FDG PET/CT in the management of eosinophilic solid and cystic renal cell carcinoma has been rarely reported. We describe FDG PET/CT findings in a case of eosinophilic solid and cystic renal cell carcinoma with lung metastases. The primary renal tumor and its metastases showed intense FDG uptake with SUV max of 29.3 for the primary tumor and 21 for the lung metastases.