Management of Merkel cell carcinoma of unknown primary origin: the Vienna Medical School experience

Abstract

Merkel cell carcinoma is a rare, but highly aggressive skin tumor. We describe our single-institution experience with the diagnosis and treatment of Merkel cell carcinoma of unknown primary (MCCUP). We conducted a retrospective medical chart review of patients treated with MCCUP at the Vienna General Hospital between 2002 and 2011. Clinicopathologic variables and outcomes were analyzed. Of the entire cohort of 57 patients, 8 patients (14%) were diagnosed with MCCUP. Three patients presented with parotid gland involvement, four patients with positive inguinal lymph nodes and one with axillar lymph nodes. CK20 staining was positive in all tumor specimens, whereas MCPyV protein was positive in four out of six patients. The primary surgical modality in five cases was wide local excision. In one patient excisional biopsy was followed by re-resection. In one case only excisional biopsy was performed due to metastatic disease at first diagnosis. Two patients underwent concomitant parotidectomy and neck dissection, and four patients received adjuvant radiation therapy. Median recurrence-free survival was 20 months. Four patients died, three of disease and one of other cause. Recurrent disease was observed in two patients and treated with radiotherapy and chemotherapy. The 1- and 3-year overall survival rates were 87.5 and 37.5%, respectively. The 1- and 3-year disease-specific survival rates were 87.5 and 62.5%, respectively. Our study shows a poor outcome in patients with MCCUP, particularly in patients with node involvement of the trunk. We therefore suggest an aggressive and multimodal treatment approach for patients with MCCUP.

Neuroendocrine Merkel cell nodal carcinoma of unknown primary site: Management and outcomes of a rare entity

“…A significant proportion of MCCUP patients (12.2%, 11/90) had a history of a previously or concurrent treated malignancy (eight basal cell carcinomas, one prostate cancer, three patients with chronic lymphocytic leukaemia), two patients were transplant recipients and another three patients were carriers of HIV. In the immunosupressed population an earlier median onset of the disease at 52 years (37-61) was observed [3,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Almost all evaluable patients presented with clinically palpable non-tender lymph nodes-IIIB disease.…”

“…Inguinal and axillary lymph node areas were initially involved in 40% (36/90) and 17.7% (16/90) of cases, respectively. Lesions ranged in colour from red, pink to blue of flesh-coloured, sometimes with a shiny surface which may mislead to a basal cell carcinoma diagnosis [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Characteristics of all patients are summarised in Table 1 and are displayed in details in Table 2.…”

Clinicopathological characteristics of head and neck Merkel cell carcinomas

“…Primary glandular Merkel cell carcinoma manifestation (“Merkel cell type”) is often difficult to distinguish from other neuroendocrine carcinomas (“pulmonary type”) or small cell carcinoma . Some authors interpret parotid gland Merkel cell carcinoma as metastases from an occult or regressed cutaneous Merkel cell carcinoma primary . Merkel cell carcinoma manifestation in intraparotideal lymph nodes confers with the theory of an occult primary.…”

Expression of 15‐lipoxygenase‐1 in Merkel cell carcinoma is linked to advanced disease

“…Histological diagnosis was confirmed by the Department of Clinical Pathology and/or the Department of Dermatopathology. Tumour samples were stained for cytokeratin 20 (CK20), neuron‐specific enolase (NSE), chromogranin A (CrA), neural cell adhesion molecule (NCAM) and thyroid transcription factor‐1 (TTF‐1) …”