Lung cancer usually metastasizes the brain, bone, liver, adrenal gland, kidneys, and gastrointestitnal tract1. Lung cancer is the first cancer of cutaneous metastasis found in men and is second to breast cancer for women2. Adenocarcinomas have been estimated to account from 3.1% to 45.0% for cutaneous lung metastases1,3. Some adenocarcinomas to the skin from the lung show well-formed, glandular structures, which are similar to gastrointestinal metastatic adenocarcinomas2.

A 67-year-old woman was referred for a pruritic, erythematous plaque on the neck for two months. The lesion was a solitary, indurated, nontender plaque (Fig. 1). A workup with weight loss and epigastric pains included a computed tomography (CT) of the chest and abdomen was performed 4 months prior to the presentation of the neck mass. The chest CT showed a enhancing mass lesion which probably indicated lung cancer. In addition, the abdomen CT and endoscopic retrograde cholangiopancreatography which were performed at that time also revealed a gall bladder (GB) carcinoma and cholangiocarcinoma. The patient subsequently received a stent insertion into the common bile duct (CBD) due to distal duct obstructions. Further workups, including a full body and brain positron emission tomography-computed tomography, demonstrated an intense and localized fluorodeoxyglucose (FDG) uptake which suggested primary lung cancer. The GB carcinoma and cholangiocarcinoma also showed. The brain and neck including thyroid displayed no definite abnormal metabolisms. The patient denied further treatments. After 4 months, she visited our outpatient clinic because of a skin lesion in the neck. The biopsy specimen showed well-circumscribed tumor nodules in the lymphatic vessel. The tumor was composed of pleomorphic cells with eosinophilic cytoplasm and mitotic figures. Rare gland formation was being noted (Fig. 2A). The tumor was stained positively for carcinoembryonic antigen, cytokeratin, and thyroid transcription factor 1 (TTF-1) (Fig. 2B) but negatively for desmin. The fact indicated that the mass in the left lung should be a lung cancer. Therefore, the carcinoma erysipeloid lesion lies in its potential as a diagnostic marker for internal malignancy even though the lung biopsy was not performed.

Carcinoma erysipeloides is an uncommon form of cutaneous metastasis. Carcinoma erysipeloides is clinically characterized as a sharply defined, erysipelas-like, erythematous plaque associated with skin metastasis. These metastases suggest inflammatory skin changes due to the direct spread of tumor cells via dermal lymphatic vessels. Although carcinoma erysipeloides is usually caused by breast carcinoma, it is also associated with other malignancies, including adenocarcinoma of the pancreas, rectum, ovary, and parotid gland4. However, carcinoma erysipeloides in a female patient originated from adenocarcinoma of the lung has been observed very rarely.

Cutaneous metastases are infrequently presented at the time of the cancer at the initial diagnosis. Several studies have demonstrated the utility of CK7, CK20 and TTF-1 when identifying the origin of tumors5. In the case of adenocarcinoma, immunohistochemistry is also quite useful. Nuclear expression of TTF-1 is a characteristic of both primary lung cancer and thyroid cancer.

We suggest that adenocarcinoma of the lung should be taken into consideration as a possible cause of inflammatory cutaneous metastasis.