An osteospongioma, also known as osteoid osteoma, is a benign bone tumor that occurs predominantly in young individuals. The term "osteospongioma" is derived from the Greek words, "osteo" meaning bone, "spongos" meaning sponge-like, and "oma" meaning tumor. This tumor is characterized by the formation of osteoid tissue, which is abnormal, immature bone, within the affected bone.
Osteospongiomas commonly affect the long bones, especially the femur and tibia, but can also occur in the bones of the hands and feet. The tumor usually presents as a small lesion, typically less than 2 centimeters in size, embedded within the bone. It often causes localized pain, which is often worse at night and relieved by nonsteroidal anti-inflammatory drugs (NSAIDs). The pain may be accompanied by swelling, redness, and warmth in the affected area.
Microscopically, osteospongiomas are composed of a central nidus, which is an area of actively growing, immature bone. Surrounding the nidus, there is a fibrovascular tissue and an outer shell of reactive bone formation. Radiologically, they appear as well-defined lucent lesions called radiolucent nidus, surrounded by a dense sclerotic rim.
The diagnostic evaluation of osteospongiomas typically involves imaging studies, such as X-rays, computed tomography (CT), or magnetic resonance imaging (MRI). If the diagnosis is uncertain or malignancy is suspected, a biopsy may be required.
Treatment options for osteospongioma include conservative management with NSAIDs for pain relief and monitoring for regression, or surgical excision of the tumor. Surgical excision is often indicated if symptoms persist or if the
