Abdominal metastases from Merkel cell carcinoma: Prevalence and presentation on CT examination in 111 patients

• Published in: Diagnostic and interventional imaging 2022-01, Vol.103 (1), p.41-48
• Main Authors: Girard, Raphael, Djelouah, Manel, Barat, Maxime, Fornès, Paul, Guégan, Sarah, Dupin, Nicolas, Soyer, Philippe, Hoeffel, Christine
• Format: Article
• Language: English
• Subjects: Abdominal metastases; Aged; Aged, 80 and over; Avelumab; Carcinoma, Merkel Cell - diagnostic imaging; Computed tomography; Female; Humans; Male; Merkel cell carcinoma; Middle Aged; Prevalence; Retrospective Studies; Skin Neoplasms - diagnostic imaging; Tomography, X-Ray Computed
• ISSN: 2211-5684; 2211-5684
• DOI: 10.1016/j.diii.2021.08.002

•Abdominal metastases are observed in 24.3% of patients with Merkel cell carcinoma, either at initial presentation (56%) or during the course of the disease (44%).•Non-regional lymph nodes are the most common sites of abdominal metastases from Merkel cell carcinoma.•Metastases from Merkel cell carcinoma may involve a variety of abdominal organs, predominantly the liver and pancreas. The purpose of this study was to report the prevalence and imaging features of abdominal metastases from Merkel cell carcinoma (MCC) on computed tomography (CT) examinations. A total of 111 patients with MCC from two institutions were initially identified. Of these, 27 patients (27/111; 24.3%) had abdominal metastases from MCC present on CT examination. There were 19 men and 8 women with a mean age of 75  ± 10.8 (SD) years (age range: 46–92 years). CT examinations were retrospectively reviewed by two radiologists and analyzed quantitatively for the number and dimensions of abdominal metastases from MCC and qualitatively in terms of location, margins, contours, homogeneity, patterns of enhancement, vascular involvement and extension of metastases from MCC. Fifteen patients (15/27; 56%) had abdominal metastatic disease at initial diagnosis and twelve (12/27; 44%) developed abdominal metastases during the course of the disease. The mean number of locations of abdominal metastases was 2.1 ± 1.12 (SD) (range: 1–5). Abdominal metastases involved abdominal lymph nodes (16/27; 59%), adrenal glands/kidneys/retroperitoneum (14/27; 52%), mesentery/peritoneum (13/27; 48%), liver (7/27; 26%) and pancreas (7/27; 26%). Vascular involvement was found in association with peritoneal/mesenteric metastases in 6/13 (46%) patients with intraperitoneal metastases or in association with abdominal lymph nodes in 4/16 (25%) patients. Ureteral encasement and/or dilatation was found in 4/14 (28%) patients with retroperitoneal metastases and 3/16 (19%) patients with abdominal lymph nodes. Metastases to the liver, pancreas, peritoneum, retroperitoneum and adrenal glands displayed internal enhancement during the arterial phase in 1/2 (50%), 4/5 (80%), 4/7 (57%) and 5/8 (62%) patients for whom arterial phase was available, respectively. : Metastases from MCC have a prevalence of 24.3% on CT examination and may involve a variety of abdominal organs, mainly lymph nodes, peritoneal and retroperitoneal structures, but also the liver and pancreas. CT features of abdominal metastases from MCC include hypervasculari