PMC3573807_01
a Breast ultrasound examination. A well-defined, smooth-surfaced, hypo- to isoechoic mass in the mammary gland, along with a hypoechoic area with suspected central necrosis. b Breast MRI. On CET1-weighted MRI, a centrally necrotic mass with margins showing strong early enhancement was noted (60 s). c MIP PET/CT. A round mass with FDG uptake (SUV: 8.7) was observed in the right breast, along with a focus of FDG uptake (SUV: 4.5) adjacent to the right humerus.
cro-0006-0055-g01.jpg
PMC3573807_01_cro-0006-0055-g01.jpg
F1
Breast ultrasound examination showed a 3.0 x 2.8 x 2.5-cm, well-defined, smooth-surfaced, hypo- to isoechoic mass in the mammary gland in the lateral portion of the right breast, along with a hypoechoic area with suspected central necrosis (fig. 1a). T1-weighted MRI demonstrated a 3.2 x 2.8 x 2.7-cm centrally necrotic mass with margins showing strong early enhancement (fig. 1b). These ultrasound and MRI findings suggested an invasive ductal carcinoma (solid tubular adenocarcinoma type) with central necrosis. FDG-PET revealed a round mass with FDG uptake (SUV: 8.7) in the right breast and a focus of FDG uptake (SUV: 4.5) adjacent to the right humerus (fig. 1c).
b Fine-needle aspiration biopsy cytology of the breast mass. Numerous spindle-shaped or naked malignant cells with prominent nucleoli were seen. Their cytoplasm was clear, and some cells contained melanin granules. Melanophages were also present. b Gross findings of the resected specimen. An approximately 3.0 x 3.0-cm, well-defined, dark-brown, melanin-containing tumor was observed in the mammary gland.
cro-0006-0055-g02.jpg
PMC3573807_01_cro-0006-0055-g02.jpg
F2
These findings led to a diagnosis of clear cell sarcoma (fig. 2a). On macroscopic examination, the resected specimen comprised an approximately 3.0 x 3.0-cm, well-defined, dark-brown, melanin-containing tumor in the mammary gland (fig. 2b).
Histopathological findings. A well-defined solid mass comprising nests of small, spindle-shaped, melanin-containing cells was observed (a). The tumor cells were immunohistochemically positive for HMB45 (b), S-100 (c), and Melan-A (d).
cro-0006-0055-g03.jpg
PMC3573807_01_cro-0006-0055-g03.jpg
F3
Histopathological examination revealed a 2.5-cm, well-defined mass composed of nests of small, spindle-shaped tumor cells with abundant, clear cytoplasm containing round nuclei and prominent nucleoli (fig. 3a). These findings led to a diagnosis of metastasis of clear cell sarcoma to the mammary gland (fig. 3b-d).