Triphasic differentiations of Merkel cell carcinoma in primary and metastatic lesions.
We present a rare case of Merkel cell carcinoma (MCC) with heterologous differentiation. The patient was an 86-year-old female patient with MCC who presented with a forearm skin tumor and left axillary lymph node swelling. Histopathologically, the malignant components of the primary and metastatic lesions showed the intermingled features of triphasic phenotype differentiation, which had distinct cell populations; MCC, sweat gland carcinoma (SGC) and malignant poorly differentiated spindle cells with myogenic differentiation were immunohistochemically showed. Moreover, an electron microscopic observation of the tumor cells revealed intracytoplasmic canaliculi and junctional structures that indicated ductal differentiation. To our knowledge, this is the first case of MCC admixed with SGC and sarcomatous components in both the primary and metastatic lesions. An immunohistochemical study, using several stem cell markers, indicated that the MCC arose from pluripotent epidermal stem cells.
Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan.
Shinichi
S
Koba
Noriyuki
N
Misago
Kotaro
K
Nagase
Noriko
N
Tsuruta
Takuya
T
Inoue
Satoshi
S
Ikeda
Shigehisa
S
Aoki
Yutaka
Y
Narisawa
D000369:Aged, 80 and over; D014408:Biomarkers, Tumor; D015266:Carcinoma, Merkel Cell / Q000473:pathology*; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis / Q000473:pathology*; D009362:Neoplasm Metastasis; D018193:Neoplasms, Complex and Mixed / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*; D013544:Sweat Gland Neoplasms / Q000473:pathology*
D014408:Biomarkers, Tumor
Merkel cell carcinoma; ductal differentiation; pluripotent epidermal stem cell; sarcomatous differentiation; sweat gland carcinoma