Cutaneous metastasis of lung cancer: an ominous prognostic sign

Cutaneous metastases in primary lung cancer rarely occurs in comparison with other organ involvement. Because of the absence of any uniform or pathognomic feature, they are often mistaken as a variety of benign lesions so that the outcome is extremely different. In this study, sixty-three cases of lung cancer with cutaneous metastases were retrospectively analyzed to determine the clinical pictures and length of survival.

Retrospective analyses were performed for 5539 cases of proven lung cancer collected at the Cancer Treatment Center in Veterans General Hospital-Taipei during the period from January 1984 to May 1994. Seventy-two cases were documented cutaneous metastases. Nine of them were excluded due to inadequate medical records on clinical course.

Group A included the majority (48/63, 76.2%) of patients who had primary lung cancer with subsequent cutaneous metastases. The other 15 patients with cutaneous metastases as the initial presentations were classified as group B. (15/63, 23.8%). There were four major clinical presentations; solitary nodules, cluster of nodules, erythematous papule and bulging mass. Solitary nodule was the most frequent pattern (41/63 65.1%), ranging in size from 0.5 x 0.5 cm to 25 x 15 cm in surface area. The chest wall and abdominal wall were the regions most likely to develop cutaneous metastases. Metastatic lesions were occasionally found over the scrotum, lip and perianal region. Adenocarcinoma was the predominant cell type of cutaneous spread (25/63, 39.7%). The survival after diagnosis of cutaneous metastasis ranged from 3 weeks to 14 months, without significant difference between two groups of patients. Twenty-two patients (35%) survived no more than one month. The median survival was 3 months.

Cutaneous metastasis, as observed in our study, is an ominous sign indicating a poor prognosis with imminent death. Physicians should be alert to its characteristics and prognostic significance.