Eccrine porocarcinoma is a rare malignant tumor. Immunostain for S-100 protein, in addition to epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA), is described to be useful in the diagnosis. Herein, we report a case of eccrine porocarcinoma with immunostain for S-100 protein which was useful in diagnoses of recurrent and metastatic lesions. The primary lesion in the left inguinal region was excised, but it recurred on the same site 14 months after the resection. The recurrent lesion showed epithelioid melanocytic findings. Three months later, metastasis to the lungs was found. Since these recurrent and metastatic lesions were dedifferentiated, typical histologic findings of eccrine porocarcinoma disappeared in biopsied specimens. Nevertheless, scattered immunoreactive cells for S-100 protein were maintained in these dedifferentiated lesions. S-100 protein positive cells could be an aid to diagnose, even if histologic findings of recurrent and metastatic lesions have changed by dedifferentiation.
Carcinoembryonic Antigen ; Eccrine Porocarcinoma ; Immunohistochemistry ; Lung ; Mucin-1 ; Neoplasm Metastasis ; S100 Proteins

Eccrine porocarcinoma is a rare malignant tumor. Immunostain for S-100 protein, in addition to epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA), is described to be useful in the diagnosis. Herein, we report a case of eccrine porocarcinoma with immunostain for S-100 protein which was useful in diagnoses of recurrent and metastatic lesions. The primary lesion in the left inguinal region was excised, but it recurred on the same site 14 months after the resection. The recurrent lesion showed epithelioid melanocytic findings. Three months later, metastasis to the lungs was found. Since these recurrent and metastatic lesions were dedifferentiated, typical histologic findings of eccrine porocarcinoma disappeared in biopsied specimens. Nevertheless, scattered immunoreactive cells for S-100 protein were maintained in these dedifferentiated lesions. S-100 protein positive cells could be an aid to diagnose, even if histologic findings of recurrent and metastatic lesions have changed by dedifferentiation.
Carcinoembryonic Antigen ; Eccrine Porocarcinoma ; Immunohistochemistry ; Lung ; Mucin-1 ; Neoplasm Metastasis ; S100 Proteins

We report a rare case of intraductal lipid-rich carcinoma of the breast with a component of glycogen-rich carcinoma. An impalpable tumor that was revealed by mammography and magnetic resonance imaging was excised. Histologic examination showed vacuolated neoplastic cells in the mammary ducts, and electron microscopy confirmed lipid droplets in the cytoplasm. The coexistence of glycogen-rich carcinoma was shown. Lipid-rich carcinoma that is coexistent with glycogen-rich carcinoma is rare, and most lipid-rich carcinomas are invasive. Intraductal lipid-rich carcinoma is difficult to detect without echography or mammography.
Breast ; Cytoplasm ; Glycogen ; Immunohistochemistry ; Magnetic Resonance Imaging ; Mammography ; Microscopy, Electron