A case of tubulocystic carcinoma of kidney and literature review

Objective To investigate the tubulocystic carcinoma (TC) of kidney in diagnosis and differential diagnosis, clinical and pathological features. Methods A case of TC was performed with HE and immunohistochemical staining, with review of the related literature. Results A man of 43 years old, who was found an occupying in the upper pole of the right kidney by B ultrasound, was performed ill-circumscribed of the right kidney. A gray solid ill-circumscribed mass was found within the renal parenchyma,which was sized of 1.5 cm × 1.5 cm × 1.0 cm. Microscopically, the tumor showed an invasive growth, and that it was composed of small tubular and vesicular structure closely spaced with slender fibrosis mesenchymal. The epithelial cells lining the tubules and cysts were flattened, cuboidal and hobnail cells, with abundant eosinophilic cytoplasm and obvious nucleolus of Fuhrman grade 3. The tumor showed positive of cytokeratin, CD10+++ and P504S+++, with low Ki-67 labeling index. Postoperative follow-up of 6 months, the patient showed no tumor recurrence and metastasis. Conclusions TC is a special subtype of renal cell carcinoma, with a tubular and cystic structure, high nuclear grade and rare mitotic. The differential diagnosis mainly includes other renal cystic lesions. The biological behavior of TC is indolent with less recurrence and distant metastasis. Key words: Kidney neoplasms; Tubulocystic carcinoma; Immunohistochemistry; Diagnosis, differential; Prognosis