A simple cyst is not always simply a cyst: A case of cystic recurrence after nephrectomy for tubulocystic renal cell carcinoma and literature review

Tubulocystic renal cell carcinoma: Two-case report and literature review

Tubulocystic renal cell carcinoma is a rare neoplasm of kidney with low metastatic tendency. There has only been a relatively small collection of literature dedicated to this subtype. Here we present two cases diagnosed in our center with detailed clinical information. Along with literature review, we aim to paint a comprehensive profile of TC-RCC. Hematuria and asthenia could be the chief complaints although most patients are asymptomatic. This lesion has a signature multilocular cystic form on radiology and enhancement of septa should reveal malignancy. Histologically, the cysts are lined by a single layer of flattened, cuboidal/columnar, and hobnail epithelium with enlarged nuclei and intermediate to large nucleoli. PAX8 and AMACR are most commonly positive while CD10 or CK7 could be focally stained in some cases. Overall, the diagnosis of TC-RCC should be based on comprehensive clinical and molecular results because early determination of the lesion could prelude a timely intervention and favorable prognosis.