Frequency and locations of systemic metastases in Merkel cell carcinoma by imaging

Abstract

BackgroundThe primary neuroendocrine skin cancer, Merkel cell carcinoma (MCC), has a well-known predilection to metastasize systemically. However, the experience of systemic metastases in MCC is mainly disseminated through case reports due to the rarity of MCC.PurposeTo elucidate the frequency and locations of systemic metastasis in MCC by reviewing the imaging of patients with metastatic MCC in a national cohort.Material and MethodsPatients with diagnosed metastatic MCC by imaging studies in Finland during 1999–2012 were included in this study. We reviewed their imaging studies to evaluate the most frequent sites for systemic metastasis and determined the latency between the primary tumor diagnosis and systemic metastasis. The material includes 30 MCC patients with complete imaging series and 187 examinations, of which 102 (54%) were CT images.ResultsThe mean latency from the primary tumor diagnosis to systemic metastasis was 2.1 years and the mean latency between the radiologic diagnosis of the metastases and death was 299 days. Metastases were recorded in several organ systems in most of the cases, and at least two separate metastatic sites in 63% of the cases. Metastatic spread was noted in 60% of the cases in distant lymph nodes. Liver and lungs were the most affected solid organs.ConclusionSystemic metastasis in MCC has no predilection site, basically every organ system can be involved. Most of the systemic metastases were recorded during the first two years after the MCC diagnosis.

Patterns of Metastasis in Merkel Cell Carcinoma

“…33 Distant LNs and intra-abdominal organs were most often the first sites of distant metastases in the present study, consistent with previous findings that these sites are frequently involved in metastatic MCC. 12,13,34 While we found that the lung (0%) and brain (3%) were rarely the first sites of distant spread, they may be subsequently involved in 30% and 13% of patients, respectively. 34 Understanding these patterns of metastasis may help to guide follow-up imaging strategies.…”

A Rare Cause of Acute Liver Failure: Diffuse Liver Metastization of Merkel Cell Carcinoma

“…Liver is one of the most important solid organs for MCC metastization, typically in the form of a nodular lesion, well-defined on imaging examinations [6]. In this case, the metastization occurred in a diffuse pattern, with less representation in the imaging techniques, which is another interesting and rare finding that supports the performance of liver biopsy.…”

LSD1 inhibitors induce neuronal differentiation of Merkel cell carcinoma by disrupting the LSD1-CoREST complex and activating TGFβ signaling

“…MCC is a highly metastatic cancer involving all organs, which contributes to its high morbidity and mortality 12 . Once seeded, micro-metastases must grow and establish a tumor.…”