Chemotherapy induced complete remission in malignant phyllodes tumor of the prostate metastasizing to the lung.

Abstract

A 35-year-old Chinese man presented with prostatism in July 1995 and was found to have urinary outflow obstruction due to prostate enlargement. The case was initially managed with repeat intermittent urinary catheterization. Computerized tomography (CT) of the pelvis subsequently showed a 5 9 cm. lobulated prostatic mass. However, repeat prostatic biopsy failed to confirm a definitive diagnosis. In January 1996 transurethral resection of the prostate was performed. Histological examination demonstrated proliferation of irregular glandular elements and papillary fronds in hypercellular stroma, and a high mitotic index was noted (10 mitoses per 10 high power field). A diagnosis of malignant phyllodes tumor of prostate was made. The patient subsequently underwent surgical resection of the prostatic mass. Intraoperatively a 60 gm. prostatic tumor was found. The tumor extended to the pelvic walls with fixation on the right side. The bladder and the rest of the peritoneum were normal. The mass was poorly circumscribed and measured 6 4 5 cm., with multiple cystic lesions that contained grayish gelatinous material. Postoperative radiotherapy was administered (total dose 59.46 Gy.) in March 1996. The patient remained disease-free until May 2001, when he complained of a 3-month history of chronic cough. Chest x-ray revealed a huge right lower lobe lung mass. Bronchoscopy showed a right lower lobe bronchial nodular growth, biopsy of which confirmed metastatic phyllodes tumor. CT of the thorax demonstrated an 11.3 10.5 11.6 cm. right lower lobe lung mass with peripheral enhancement of cystic components, and probable involvement of the chest wall and mediastinal structures (fig. 1). CT of the pelvis did not reveal evidence of local recurrence. In view of the inoperable nature of the lung metastasis, salvage chemotherapy consisting of 3 days of ifosfamide (1.5 gm./m. per day) and 2 days of doxorubicin (30 mg./m. per day) was administered every 3 weeks. CT of the thorax after 3 cycles of chemotherapy showed significant reduction of the lung mass to 9 5 cm. and separation of the mass from the adjacent structures, with almost complete resolution of peripheral enhancement (fig. 2). Despite minimal organ toxicity with the treatment regimen, further chemotherapy was withheld after cycle 5 due to major treatment associated psychological stress, and a right lower lobe lobectomy was performed in October 2001. Histological evaluation of the lung mass did not demonstrate any viable tumor. At 5-month postoperative followup the patient remained well with no evidence of disease. DISCUSSION