Procedure: Left breast mass biopsy followed by modified radical mastectomy (MRM).

Diagnosis: Phyllodes tumor, low grade. Tumor size: 27 x 26 x 15 cm. Tumor weight: 5600 grams. Surgical resection margins are all clear.  Skin ulcer, with fibrin deposition, granulation tissue and chronic inflammation. Nipple and areolar region: Unremarkable. Eleven (11) axillary lymph nodes are identified, none of which show metastatic tumor. The non-neoplastic breast tissue shows fibrocystic change/disease.

Comments: This phyllodes tumor most likely falls in the category of low grade based on the rather low mitotic count with a maximum of 2 mitosis per high power field in most mitotically active areas; however, the majority of the blocks show rare mitosis. The stromal nuclear pleomorphism is minimal and the margin is pushing rather than infiltrative.  Tumor size, however, is very large. The stromal component shows interestingly in places muscle and osseous metaplasia. It is, however, well known that no single feature alone or in combination is sufficient to predict the clinical behavior of this neoplasm with absolute certainty. Based on the negative surgical resection margins and the fact that this patient had a mastectomy and the phyllodes tumor is low grade, all of these features would favor a good prognosis, with low rate of local recurrence and rare incidence of distant metastasis.

Patient did well postoperatively and had no evidence of local recurrence or distant metastasis on follow up in eight years.