A rare case of metastatic malignant phyllodes tumor with osteosarcomatous differentiation presenting with intestinal obstruction

Phyllodes tumors (PTs) are uncommon biphasic breast neoplasms constituting 0.5 to 1.0% of all breast tumors. Malignant PTs form a very small proportion of these and may metastasize, especially to the lungs and bones. Aggression and metastatic potential are accentuated in tumors exhibiting heterologous differentiation. Metastases to the gastrointestinal tract (GIT) have seldom been reported and are often confined to a segment of the digestive tract. In the absence of relevant clinical history, such patients presenting with gastrointestinal symptoms can lead to diagnostic perplexities. We report a unique case of a malignant PT with extensive osteosarcomatous differentiation and widespread metastases to the GIT.