Osseous Metaplasia in Uterine Leiomyoma: A Case Report

The leiomyoma uteri is one of the most common tumours of the female genital tract. It is more common in women above 50 years and is known to shrink in size after menopause. The symptoms it produces depend upon its location, whether it is submucosal, intramural, or subserosal. It is known for its histological variations in the form of hyaline degeneration, myxoid degeneration, calcification, and cyst formation. Heterologous tissue differentiation is an uncommon phenomenon, and osseous metaplasia is even rarer. Here, we report a rare case of leiomyoma with osseous metaplasia in a nulliparous woman. A 30-year-old nulliparous female presented with a history of abnormal uterine bleeding and abdominal pain, with an obstetric history of two spontaneous abortions at eight weeks and 10 weeks of gestation, respectively. Her biochemical and haematological investigations were within normal range. Ultrasound examination revealed multiple submucosal fibroids, with the largest one measuring 6×4×4 cm, for which the patient underwent myomectomy. The histopathological examination revealed leiomyoma with osseous metaplasia and hyaline degeneration with areas of calcification. There was no atypia, mitosis, or necrosis. Patient was discharged, and her two sequential follow-ups were uneventful. The novelty of this case report lies in the fact that osseous metaplasia in leiomyoma is quite a rare entity, with very few cases reported in the literature. Its recognition lies in its diagnostic significance to rule out sarcoma with heterologous differentiation. It highlights the importance of adequate sampling of gross specimens and careful histopathological examination to rule out this benign entity