Clinical and histopathological characteristics of cutaneous metastases from solid organ cancers: Experience of dermatology in a tertiary referral hospital

Background/Aim: In various studies, it is shown that cutaneous metastases of solid organ cancers are associated with advanced stage disease, lower disease-specific survival rate, and poor prognosis. Metastatic cutaneous disease may be observed in different morphologies. Histopathologically epidermal/dermal/epidermodermal infiltration, solid/nodular structures, interstitial pattern, and perineural invasion may be evident as accompanying features. In the present study, we aim to analyze demographical, histopathological, and clinical characteristics of cutaneous metastases from solid organ cancers in 37 patients. Materials And Methods: Thirty-seven patients diagnosed with biopsy-proven cutaneous metastases of solid organ cancers between January 2006 and January 2019 were retrospectively evaluated in the study. Results: Breast cancer was the primary cancer in 22 patients, whereas 13 patients were diagnosed with other solid organ cancers. The most common solid cancer which presented with skin metastases was breast cancer (22, 59.5%) followed by lung cancer (3, 8.1%), whereas colorectal cancer and lung cancer were the two most common cancers which metastasized to the skin in male patients. Two patients had cancer of primary unknown. The mean age at the diagnosis of first cutaneous metastasis was 58.1 ± 12.4 years. Twenty-six (70.3%) patients had primary cancer diagnosed first, whereas 11 (29.7%) patients had cutaneous metastasis diagnosed first. Breast cancer is shown to metastasize to the trunk at a significantly higher rate compared with other types of solid cancers (P = 0.02). Nodule (37.8%, 14) was the most frequently observed primary lesion of the cutaneous metastases morphologically, followed by plaque (18.9%, n = 7), tumor (13.5%, n = 5), and papule (8.1%, n = 3). Seven (18.9%) patients presented with more than one morphology. Histopathologically, micronodular structure was the most commonly observed structure. The mean time between the diagnosis of primary cancer and death was 60.62 ± 53.93 months (range: 6–156). The mean duration between the appearance of cutaneous metastasis and death was 10.5 ± 6.4 months (range: 1–24). There was not any statistically significant difference between the primary cancer type and the eluded time between death and primary cancer diagnosis. In addition, we were not able to find any statistically significant relationship between living-to-dead ratio and primary cancer type, presence of other organ metastases, and treatment status at the time of the emergence of cutaneous metastases. Conclusion: All in all, we would like to highlight the importance of diagnostic skin biopsy, especially in elderly patients presenting with cutaneous nodules of unknown origin. The possibility of cutaneous metastasis should always be kept in mind in patients with a history of malignancy even after long periods of recovery.