Beta‐hCG–producing malignant phyllodes tumour

Phyllodes tumours (PTs) of the breasts are rare fibroepithelial tumours accounting for less than 1% of all breast tumours. They have a wide range of presentations, ranging from benign‐natured tumours that behave similarly to fibroadenomas, to aggressive malignant tumours that can rapidly advance both locally and distally. Histologically, PTs are classified into benign, borderline, or malignant based on a combination of the following five features: degree of stromal cellularity, stromal cell atypia, mitotic activity, infiltrative or circumscribed margins, and presence or absence of stromal overgrowth. Malignant tumours demonstrate high levels of stromal cellularity and atypia, infiltrative margins, high mitotic rate (>10 mitoses per 10 high‐power fields), and the presence of stromal overgrowth. Treatment predominantly relies on complete excision of the lesion, although treatment regimens for malignant PTs with adjuvant chemoradiation lack standardization as a result of its rarity. Malignant tumours are also often associated with paraneoplastic syndromes such as recurrent hypoglycaemia and hypertrophic osteoarthropathy. Here, we report a case of recurrent malignant PT with serum beta‐human chorionic gonadotrophin secretion.