Bisphosphonate-related spindle cell carcinoma and osteonecrosis

Abstract

A 48-year-old female with a complaint of persistent pain referred to the Imam Khomeini (Tehran, Iran) in 2018. Based on the radiographic findings, radiolucent lesion found in the right mandible and she had alendronate administration approximately for 10 years. Since the past 6 months, the lesion detected in the right mandible. According to the computed tomography scan, a large lytic destructive lesion with a soft-tissue component was seen at the right mandibular ramus. Microscopic examinations revealed the proliferation of anaplastic spindle-shaped cells arranged in interlacing bundles and whorled patterns. Nuclear polymorphism, scattered cells with hyperchromatic nuclei and increased mitotic activity were notable. Immunohistochemistry findings for tissue section composed of spindle cell proliferation revealed Ki67 (20% positive in hotspots), scattered positive right side incisional biopsy was done. The observation revealed hyperplastic and disorganized squamous epithelial lesion, suggestive of spindle squamous cell carcinoma and osteonecrosis in this patient.

Keywords: Bisphosphonate; osteonecrosis; spindle cell carcinoma; women.

Figure 1

Spindle cell carcinoma involving the right mandibular ramus has destroyed the posterior border of the ramus, retromolar area and ramus

Figure 2

Microscopic features of the lesion, epithelial cells in the overlying oral epithelium show nuclear polymorphism and scattered hyperchromatic nuclei. Significant increased mitotic figures are noticeable (×400). (a) The transition of the epithelial cells to the mesenchymal cells is evident (×400). (b) Immunostaining of ki-67 reveals nuclear staining in more than 20% of the spindle cells (×400). (c) Spindle cells in the stroma show immunoreactivity for pan-cytokeratin. Staining of the overlying oral epithelium serves as internal control for the staining (×40) (d)