Clinical Characteristics of 90 Macrodactyly Cases

Purpose: Macrodactyly is a rare, nonhereditary congenital deformity. Digital enlargement in macrodactyly involves all tissue types and presents alone or as part of a congenital deformity syndromes. Macrodactyly treatment largely depends on surgeons’ experience and knowledge. Because there is a paucity of large cohort studies of macrodactyly in the literature, our goal was to retrospectively analyze macrodactyly cases in order to define a better system for diagnosis, classification, and prognosis. Methods: Medical records of 90 Chinese macrodactyly patients, including demographic characteristics, clinical presentations, anatomical distributions, x-rays, pathological findings, and treatments, were reviewed. Genetic analyses of 12 patients were also reviewed. Results: Disease incidence was similar across sex and geographical regions. Multiple-digit involvement was 2.6 times more frequent than single-digit involvement. The index finger, middle finger, and thumb were most commonly involved. Two digits were affected more often than 3, with the affected digits adjacent in most cases. The affected digit was in the median nerve innervation distribution in 79% of cases and was accompanied by enlargement and fat infiltration of the median nerve. Seven cases had syndactyly. Ten of the 12 cases subjected to PIK3CA mutation analysis were positive. Conclusions: Macrodactyly represents a heterogeneous group of conditions, without significant sex or geographical predilection, which is usually present at birth. A high PIK3CA mutation–positive rate in affected tissues suggests a similar cellular mechanism for overgrowth in patients with various clinical presentations. Type of study/level of evidence: Prognostic IV.