Our purpose is to report two cases of fibromatosis in two women of 34 and 48 years old respectively that clinically appeared as a invasive breast carcinoma, particularly for the cutaneous retraction they showed. The histopathological diagnosis was done based on specimens studied with the common technique of paraffin embedding and Hematoxilin & Eosin staining. Both patients had firm poorly demarcated nodules with the histopathological pattern of classic fibromatosis. Mammary fibromatosis is an infrequent relapsing entity, not suspected in differential clinical diagnoses. The pathologist should bear it in mind, especially in frozen biopsies.