Malignant phyllodes tumor of the breast with hypoglycemia: report of a case

A surgically resected case of giant malignant phyllodes tumor of the breastassociated with a hypoglycemic attack is reported. A 54-year-old woman wasreferred to our hospital with loss of consciousness and a huge chest walltumor. She was diagnosed as having a malignant phyllodes tumor by coreneedle biopsy and underwent palliative simple mastectomy because lungmetastasis was detected on computed tomography and by other imagingmodalities on admission. The preoperative laboratory data revealed a verylow fasting blood sugar level of 37 mg/dl. After removal of the tumor, theblood sugar level gradually normalized (90-100 mg/dl) and the plasmainsulin-like growth factor-II (IGF-II) level promptly decreased. The IGF-IIlevel of tumor extracts was high (2500 ng/g wet weight) and the majority ofatypical cells stained positively for IGF-II immunohistochemically. Thesefindings suggested that the patient's hypoglycemia was associated withIGF-II produced by a giant malignant phyllodes tumor that consumed glucose.