osteopoikilosis

Osteopoikilosis is a rare, benign sclerosing bone dysplasia characterized by multiple small, round or oval sclerotic foci within the epiphyses and metaphyses of the long bones, pelvis, and carpal and tarsal bones. It is usually inherited in an autosomal dominant pattern and commonly identified in adolescence or early adulthood. In some cases it occurs as part of Buschke-Ollendorff syndrome, in which osteopoikilosis coexists with elastin-containing skin nevi.

Most individuals are asymptomatic and the radiographic findings are typically incidental. When symptoms occur, they are non-specific and pain is not typical.

Radiographs show numerous, well-defined sclerotic foci, usually periarticular and symmetrically distributed, most often in the pelvis, proximal femur and tibia, and in the carpal/metacarpal bones and calcaneus. The cortex is preserved. CT or MRI can delineate the lesions; MRI generally shows low signal intensity within the foci. A bone scan may be normal or show mild uptake; the pattern can help distinguish these lesions from osteoblastic metastases, which usually show more extensive involvement and symptoms.

Differential diagnosis includes osteoblastic metastases and other sclerosing bone dysplasias. The presence of tiny, symmetric periarticular foci with no destructive changes and the absence of systemic disease favors osteopoikilosis; skin lesions support the diagnosis in Buschke-Ollendorff syndrome.

No specific treatment is indicated for the bone lesions. Management is reassurance and monitoring; if associated skin lesions are present, they may be addressed separately. Genetic counseling can be offered given the autosomal dominant inheritance. The prognosis is excellent; the lesions persist lifelong and do not cause malignant transformation.