Calcifying aponeurotic fibroma: Radiologic-pathologic analysis of ten cases and review of the literature

Calcifying aponeurotic fibroma (CAF) is a very rare benign entity that principally affects the volar fascia, tendons, and aponeuroses of the hands and feet with a peak incidence of between 5 and 15 years, although there have been cases found for a wide age range and at various anatomical sites. We present ten CAF cases; consisting of eight children and two adults. CAF occurred in the extremities in nine of the cases and in the chest wall in one case. CAF ultrasound and radiological findings are nonspecific but may help orientate diagnosis. Magnetic resonance imaging should be performed when there are doubtful cases, when occurring in nontypical sites, and when there are cases of nontypical clinical presentation. Histologically, all cases showed two components, a fibromatosis-like component and a nodular component. Chondroid areas were present in five cases. Calcifications were observed in nine cases. ERG immunostaining showed the same patterns in all the cases; diffuse positivity in pericalcified areas, and patchy positivity in areas away from calcifications. CAF has distinctive histopathological features which should aid in the differential diagnoses with other entities.