Multilocular cystic renal cell carcinoma has been recently excluded from clear cell renal cell carcinoma (CCRCC) category and re-designated as multilocular cystic renal neoplasm of low malignant potential (MCRNLMP) due to its uniformly good outcomes. While strict distinction between MCRNLMP from predominantly cystic CCRCC (pc-CCRCC) is being emphasized, the significance of extensive true cystic component in CCRCC has not been investigated. Herein, we analyzed 57 MCRNLMP, 69 pc-CCRCC, and 46 non-cystic CCRCC. There were no statistically significant differences between the three subtypes in age, gender, and laterality. ISUP grades were 1 (73%) or 2 (27%) for MCRNLMP; for pc-CCRCC were 1 (31%), 2 (60%), and 3 (9%); and for non-cystic CCRCC were 1 (9%), 2 (52%), 3 (26%), and 4 (13%). MCRNLMP were either pT stage 1 (91%) or 2 (9%), pT stages for pc-CCRCC were 1 (92.5%), 2 (1.5%), and 3 (6%) and for non-cystic CCRCC were 1 (58.7%), 2 (6.5%), and 3 (34.8%). None of MCRNLMP patients developed recurrences or metastases, and only 1 contralateral kidney tumor and 1 metastasis developed in pc-CCRCC. In contrast, 19 patients with non-cystic CCRCC developed metastases (5-year PFS 58%, CI 38.3-73.5%), and 1 patient died of disease. Monosomy 3 was common in both MCRNLMP (3/3) and pc-CCRCC (6/7). This large series of MCRNLMP confirms its indolent behavior, shows that pc-CCRCC has significantly better prognosis than non-cystic CCRCC and may define the lower grade spectrum of CCRCC. We recommend that the presence and extent of CCRCC cystic component should be documented in the pathology report.
Virchows Archiv : an international journal of pathology. 2018 May 17 [Epub ahead of print]
Maria Tretiakova, Vikas Mehta, Masha Kocherginsky, Agata Minor, Steven S Shen, Sahussapont Joseph Sirintrapun, Jorge L Yao, Isabel Alvarado-Cabrero, Tatjana Antic, Scott E Eggener, Maria M Picken, Gladell P Paner
Department of Pathology, University of Washington School of Medicine, 325 9th Ave, Box 359791, Seattle, WA, 98104, USA. ., Department of Pathology and Laboratory Medicine, Loyola University Medical Center, Maywood, IL, USA., Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA., Department of Pathology, University of Chicago, Chicago, IL, USA., Department of Pathology, Methodist Hospital, Houston, TX, USA., Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Pathline/Emerge Laboratories, Ramsey, NJ, USA., Department of Pathology, Mexican Oncology Hospital, IMSS, Mexico City, Mexico., Department of Surgery, Section of Urology, University of Chicago, Chicago, IL, USA.