Defining the Vascular Anomalies in Maffucci Syndrome: A Systematic Review.

Background: Maffucci syndrome (MS) is a rare disorder characterized by enchondromas and vascular anomalies (VAs). However, the nomenclature used to define MS in the literature is variable. The purpose of this review is to evaluate definitions of MS and characterize VAs reported in patients with MS, in relation to International Society for the Study of Vascular Anomalies (ISSVA) definitions. Methods: MEDLINE and Embase were searched for articles that discussed MS. Articles were analyzed for VAs identified in the disease definition. Case reports of MS were analyzed for VAs diagnosed in their patients. Results: Since 1950, 265 articles have defined MS. Disease definitions have varied widely. Over half of the articles identified "hemangioma" nonspecifically as the defining VA, whereas only 2 recognized the ISSVA definition of MS as "enchondromas with venous malformations ± spindle-cell hemangiomas (SCHs)." Of 220 patients in 183 primary reports, only 36 (16%) patients had a VA diagnosis consistent with a specific ISSVA diagnostic label. Only 9 (4%) patients were reported to have venous malformations per the 2018 ISSVA definition of MS, whereas 23 (11%) were reported to have SCHs in the absence of venous malformations. Conclusions: The definition of MS remains inconsistent due to the use of ambiguous and outdated nomenclature for classifying VAs. This makes it difficult to identify the true constellation of VAs present in the disease. Clinicians and researchers should adhere to modern nomenclature when discussing VAs. Given multiple histologically confirmed SCHs in the absence of venous malformations, it seems that either lesion may be diagnostic for MS.