Cutaneous metastasis is a relatively uncommon manifestation of visceral malignancies. The overall incidence of cutaneous metastasis from visceral neoplasm is 5.3% and ranges from 0.7% to 9%1,4,5
. The highest incidence of cutaneous metastasis has been seen for breast cancer. Cancers of the lung, colon/rectum, kidney, ovary, and bladder all have similar rates for cutaneous metastasis, ranging from 3.4% to 4%5
. Gastric cancer causes only 6% of all skin metastases2
, and cutaneous metastasis occurs in 0.8% of all gastric cancers6
. Thus, gastric cancer is a relatively rare cause of cutaneous metastasis from visceral cancer. Multiple subcutaneous nodules on the trunk seem to be the most common manifestation of such metastases7
and the typical location of gastric cancer cutaneous metastases has been demonstrated to be the umbilical area (Sister Joseph's nodule)8
, which is near the primary cancer.
In the Korean-language scientific literature, Kim et al.9
investigated the frequency of cutaneous metastasis from gastric cancer in 14,053 patients who were diagnosed with gastric cancer, and found that 27 (0.19%) had cutaneous metastasis. The reported location of the cutaneous metastases were abdomen (9 cases, 33%), face (6 cases, 22.2%), scalp (6 cases, 22.2%), chest (3 cases, 11.1%), extremities (3 cases, 11.1%), neck (2 cases, 7.4%), and pubic area (2 cases, 7.4%). In addition, in the same literature, cases of scalp10,11
metastasis from gastric cancer have been rare.
The case presented here is also remarkable because of the unusual location of the cutaneous metastasis. Cutaneous metastasis in the palmar area from visceral cancer has been reported in only four cases in the English-language literature13-16
since Camiel et al. originally reported skin metastasis on palm and sole from lung cancer. However, this had not yet been reported in the Korean-language literature. Presentation of a solitary ulcerative plaque, as in our case, may lead to multiple differential diagnoses such as granuloma pyogenicum, cutaneous lymphomas, or another skin cancer; a biopsy is needed for the accurate diagnosis of these patients.
Histologic appearance has been the most important feature in the diagnosis of cutaneous metastases, as they are similar to the primary tumor. The histologic features of cutaneous metastases from gastric cancer have been observed to be mainly those of an adenocarcinoma. In the current case, the features were identical to those of the gastric carcinoma, and tumor cells with cytoplasmic mucin and laterally displaced nuclei were recognized upon examination of the skin biopsy.
Because of advances in cancer therapy, the life expectancy of patients with cutaneous metastases has increased; however, cutaneous metastases remain a poor prognostic sign. Bordin and Weitzner17
reported that the duration of survival from the time of diagnosis of metastatic carcinoma in the skin averaged 11.4 weeks, with a range of 2 to 34 weeks. The treatment for most patients has been palliative, and although chemotherapy and radiotherapy have been often used in such patients, they have been ineffective in many cases18
In conclusion, we presented a very uncommon case of gastric metastatic tumor with a single palm plaque observed instead of several subcutaneous trunk lesions. This case emphasizes that newly appearing skin lesions may be the first presentation of advanced visceral cancer and should be appropriately investigated. Despite the low frequency, persistent indurated erythema and all skin plaques of undetermined causes must be biopsied to rule out a diagnosis of cutaneous metastasis from visceral malignancy.