De-Differentiated Tubulocystic Carcinoma of the Kidney: A Series of 3 Cases with FISH Analysis
Turki Al-Hussain, Liang Cheng, Shaobo Zhang, Jonathan I Epstein. The Johns Hopkins Hospital, Baltimore; Indiana University School of Medicine, Indianapolis
Background: Tubulocystic renal cell carcinoma (RCC) is relatively rare and was first described as a low grade variant of collecting duct carcinoma. This variant was not recognized in the 2004 WHO classification and only received its current name in 2009 in a series of 39 cases from 7 large institutions. It is low grade with only 2/17 cases with follow-up in this prior series developing metastases. Its relationship to collecting duct carcinoma is controversial and recent studies have linked it with papillary RCC. Only 1 case from 2011 describes a sarcomatoid tubulocystic RCC.
Design: 3 consult cases of de-differentiated tubulocystic RCC were identified. FISH was performed on 2 cases with available material.
Results: Two lesions measuring 9.5 cm. and 3.8 cm. were described as partly solid and cystic. One case was grossly a 14.0 cm cyst with a granular lining. Microscopically, all had classic areas of circumscribed tubulocystic RCC occupying 30%, 80%, and 90% of the tumor. 2 cases had small components of papillary RCC and 1 case a central large cystic component. In 2 cases, a proliferation of small tubules infiltrated away from the main mass with typical features of collecting duct carcinoma. In the 3rd case, a focus of sarcomatoid carcinoma was seen adjacent to the tubulocystic RCC. In 2 cases, tumor invaded peri-renal tissue. The 3rd case was organ confined with vascular invasion. 1 patient died 9 months post-operatively with metastases to the abdominal wall and femur. The 2nd case developed metastases to retroperitoneal nodes 3 years post-operatively. The 3rd patient was lost to follow-up.
|Tumor Pattern||Chromosome 7||Chromosome 17||Chromosome Y|
|Case 1. Tubulocystic||Disomy||Trisomy||Loss|
|Case 1. De-differentiated||Disomy||Trisomy||Disomy|
|Case 2. Tubulocystic||Disomy||Trisomy||Disomy|
|Case 2. De-differentiated||Disomy||Trisomy||Disomy|