Rarest of the Rare - Malignant Solitary Fibrous Tumour of the Breast: Case Report and Literature Review.

Malignant solitary fibrous tumor of the breast is one of the rarest types of breast malignancy. To the best of our knowledge, only six cases have been reported so far. Here we have presented such a case from India, where a 52-year-old lady presented with a 10 cm x 8 cm breast lump. Diagnosis was achieved with the help of FDG PET, histopathology and immunohistochemistry, which showed nuclear positivity for STAT6. Fluorescent in situ hybridization (FISH) molecular study for SS18-SSX was used to rule out the differential diagnosis of synovial sarcoma. Guidelines for the management of this type of breast malignancy still do not exist. We have done a review of the literature in order to discuss which might be the best management in such cases. Evidence on this very rarest type of breast malignancy is still evolving. The interest in the case described here relies on its rarity, difficulties in achieving diagnosis and formulation of the proper management.