A contemporary series of renal masses with emphasis on recently recognized entities and tumors of low malignant potential: A report based on 624 consecutive tumors from a single tertiary center

Maria Rosaria Raspollini, Ilaria Montagnani, Rodolfo Montironi, Liang Cheng, Guido Martignoni, Andrea Minervini, Sergio Serni, Giulio Nicita, Marco Carini, Antonio Lopez-Beltran

Research output: Contribution to journalArticle

2 Scopus citations


Introduction A number of new renal tumor entities have been recognized by the 2016 World Health Organization classification of urologic tumors. The classification includes tumors with different behavior and introduces one tumor with low malignant potential, the multilocular cystic clear cell renal cell neoplasm of low malignant potential (mcCCRCNLMP). However, some categories still labeled as “carcinoma”, such as clear cell papillary renal cell carcinoma (CCPRCC), renal angioleiomyomatous tumor (RAT), and tubulocystic carcinoma (TCRCC), all with a particularly good prognosis when diagnosed as low stage, show no malignant behavior: in fact, no metastases have been reported in these categories when surgically excised. Current experience is limited to supporting these neoplasms as benign entities although, recent literature data is defining these entities as “low malignant potential tumors”. Material and methods We conducted a search through our files on a consecutive series of 624 renal tumors diagnosed over a period of 2 years to address the incidence of this category of tumors. Results Applying strict histological criteria, the “low malignant potential” tumors, comprised 7% of renal masses that are less than 4 cm in size and 3.8% of renal masses measuring 4−7 cm in the series of 624 renal tumors. When benign tumors are taken into considerations, the benign and “low malignant potential tumors” represent about one third of renal masses <4 cm and one sixth of renal masses between 4 and 7 cm. All these cases have not shown recurrence or metastasis at follow-up, mean follow-up of 18 months (range 6−30 months). Conclusions This information may assist urologists in developing guidelines for counseling and proper clinical management for patients with “low malignant potential” tumors or small renal masses.

Original languageEnglish (US)
Pages (from-to)804-808
Number of pages5
JournalPathology Research and Practice
Issue number7
StatePublished - Jul 1 2017



  • Clear cell papillary renal cell carcinoma
  • Low malignant potential tumors
  • Multilocular cystic clear cell renal cell
  • PT1 renal tumor
  • Small renal tumor
  • Tubulocystic carcinoma

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Cell Biology

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