A review of merkel cell carcinoma with emphasis on lymph node disease in the absence of a primary site

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.…”

Merkel cell carcinoma of lymph node with unknown primary has a significantly lower association with Merkel cell polyomavirus than its cutaneous counterpart

“…2 Rare cases of highgrade neuroendocrine tumor have been encountered in the lymph nodes with unknown extranodal primary, and these tumors were often described as 'Merkel cell carcinoma of lymph node with unknown primary' as they exhibit similar morphologic and immunophenotypic features to those in the skin Merkel cell carcinoma. [5][6][7][8][9][10][11][12][13][14] However, it is not clear whether the nodal Merkel cell carcinoma is a primary tumor of lymph node or represents a metastasis from an occult or regressed extranodal lesion. To establish an accurate diagnosis of nodal Merkel cell carcinoma can be challenging, and it has to be separated from other nodal metastatic neoplasms, such as small cell carcinoma and lymphoblastic lymphoma.…”

Merkel cell carcinoma of the head and neck: A retrospective case series

“…28,29 We added one additional patient with MCC of unknown primary site to the few documented cases already in the literature. [30][31][32][33] MCC without a primary tumor location can be a diagnostic dilemma for the surgical pathologist because of its histologic similarities with poorly differentiated small cell and other neuroendocrine carcinomas. The differential diagnosis includes metastatic small cell carcinoma, lymphoma, small cell melanoma, and sarcoma.…”