Abstract

In a unique clinical presentation, a 20-year-old female with a known left distal Tibial Osteoblastoma (previously treated via curettage) developed pain and weight-bearing difficulties in her left lower limb six months later. Subsequently bone scan revealed a unprecedented clinical presentation: residual activity in the treated Osteoblastoma alongside additional foci of increased tracer uptake on skeletal scintigraphy, localized to the bilateral anterior superior and inferior iliac spines. Subsequent radiographs confirmed sessile bony outgrowths in these locations, consistent with multiple pelvic Osteochondromas (an uncommon variant). Notably, these Osteochondromas lacked associated radiolucencies or cortical destruction. Further MRI confirmed the Osteochondroma diagnosis. Interestingly, the patient declined surgical intervention for the asymptomatic Osteochondromas, prioritizing ongoing treatment for the primary Osteoblastoma. This case highlights the rare co-occurrence of these distinct tumor types in an uncommon usual pelvic location, emphasizing the importance of patient centered treatment approach based on patient preferences and clinical context.

Key words: Osteochondroma, Multiple exostosis, Osteoblastoma, Anterior iliac spines, Hereditary Multiple Osteochondromas