Pulmonary metastases from Abrikossoff's tumour. Transformation capability of a benign granular cell tumour

Introduction Abrikossoff's tumour or granular cell tumour is usually benign involving multiple anatomical sites, most frequently the head, neck and airways. Occasional observations of aggressive malignant tumours have been reported, associated with a poor prognosis. Case report We report the case of a mammary Abrikossoff's tumour, initially considered benign and treated solely by local surgery. Seven years later the tumour was responsible for the development of sub-cutaneous and pulmonary metastases. Local surgery was again the only treatment given in the absence of evidence for the effectiveness of alternative treatment with chemotherapy or radiotherapy. Conclusion This original observation reports the case of a benign granular cell tumour that underwent malignant transformation after an interval of 7 years as indicated by the clinical progress and the cellular proliferation index Ki-67.