Cytodiagnosis of Telangiectatic Osteosarcoma in a Patient with Previous Fracture Humerus Surgery with Plating: A Case Report

Abstract

Telangiectatic Osteosarcoma (TO) is a rare variant of osteosarcoma, accounting for 0.4-12% of cases. It is a high-grade malignancy occurring in adolescence and the adult population. It commonly occurs in the bones of the limbs but rarely in the humerus. It is assumed to originate in stem cells of the mesenchyme or from transformed osteoblasts. The initial X-ray of TO would show an osteolytic lesion over the metaphysis of the long bone. However, the radiographic imaging techniques may not correlate with the histological variant of osteosarcoma. It has been rarely diagnosed and reported in the literature in terms of diagnostic modality using Fine Needle Aspiration Cytology (FNAC). Its cytological as well as histological diagnosis is challenging. However, the diagnosis of TO has numerous implications such as prognosis, differential diagnosis, and treatment options. The present clinical and pathological case images depict the unusual features of TO involving the upper humerus by an osteolytic lesion. Its clinical and diagnostic chronology is interesting due to the occurrence of TO in a case that underwent surgery for a fractured humerus with plating. The plate fixation in this particular case was surrounded by osteolytic tumour tissue extending into the soft tissue. The FNAC under Ultrasonography (USG) guidance was carried out. The smears of the aspirated material typically showed malignant spindle cell fragments with a few gaps of remnant sinusoids entrapping sparse red blood cells. The smears also showed osteoid material which was lacy in character. This case has several noteworthy features in the form of cytomorphological description of the telangiectatic variant of osteosarcoma, its occurrence following plating, and subsequent confirmation on histology and Immunohistochemistry (IHC).