Pediatric aneurysmal bone cyst of the distal tibia.

A rare, large pediatric aneurysmal bone cyst with pathologic fracture of the distal tibia of a 4-year-old female was presented. Classic radiographic and magnetic resonance imaging findings have been discussed. In a comprehensive review of the literature, aneurysmal bone cysts are an infrequently reported neoplasm of the foot and ankle bones. Lesions are characteristically seen in patients younger than 20 years of age, but rarely younger than 5 years. The benign cyst has a 2:1 female-to male predilection. In long bones, the lesion is typically metaphyseal in nature. Although the pathogenesis is still unknown, there exists the possibility of two types of aneurysmal bone cysts: a primary type without preexisting lesion and a secondary form associated with some other lesion. The diagnosis of aneurysmal bone cyst can be strongly suspected by correlating the radiographic and magnetic resonance imaging findings. For definitive diagnosis, accurate histologic evaluation is imperative to rule out any confusion or possibility with a malignant tumor.

Amniotic band syndrome.

Amniotic band syndrome is an uncommon, congenital fetal abnormality with multiple disfiguring and disabling manifestations. A wide spectrum of clinical deformities are encountered and range from simple ring constrictions to major craniofacial and visceral defects. Lower extremity limb malformations are extremely common and consist of asymmetric digital ring constrictions, distal atrophy, congenital intrauterine amputations, acrosyndactyly, lymphedema and clubfoot. Although debated, early amnion rupture with subsequent entanglement of fetal parts (mostly limbs and appendages) by amniotic strands is the primary theory of pathogenesis. The sporadic nature of this congenital anomaly is discussed, as well as a case study involving the surgical correction of an associated rigid clubfoot deformity.