RESUMO
INTRODUCTION AND IMPORTANCE: The purpose of this study is to highlight a rare entity of unusual location and to report our therapeutic attitude in this regard, while detailing the diagnostic criteria and therapeutic management. CASE PRESENTATION: We describe the case of a 32 years old woman with a swelling of the big toe initially neglected by the patient, the evolution is marked by a discomfort when wearing shoes, it was a firm mass of 2 cm slightly painful without local inflammatory signs with bone lysis on radiography, The MRI showed an invasion of the flexor and extensor tendons of the hallux, our approach was a carcinological tumor exeresis and arthrodesis while preserving the toe since the pedicle was not invaded, the histological examination confirmed the diagnosis and the evolution is good without tumor recurrence. CLINICAL DISCUSSION: A giant cell tumor of the tendon sheaths (GCTTC) usually presents as a firm slow growing mass, the radiological assessment shows bone erosions, an MRI for extension assessment and histological confirmation are mandatory, malignant degenerations are unusual but should always be investigated, treatment is based on the most complete surgical resection to avoid the risk of recurrence, adjuvant radiotherapy can be done in case of incomplete resection but it is a controversial subject. CONCLUSION: GCTTC are benign tumors that may be locally malignant because of the invasion of noble structures, which makes their complete exeresis difficult. The diagnosis is based on clinical and radiological criteria and requires histological confirmation.