Pleomorphic adenoma (benign mixed tumor) of the breast: a case report and review of the literature.
We report a case of pleomorphic adenoma (benign mixed tumor) of the breast, which is an extremely rare location for this tumor. Examination of a 55-year-old woman unexpectedly revealed a mass measuring 0.8 cm in diameter in the subareolar region of the right breast. Excisional biopsy was performed, and the tumor histologically showed pleomorphic adenoma composed of duct epithelial cells, myoepithelial cells, and a myxochondroid matrix. Immunohistochemically, duct epithelial cells were positive for the estrogen receptor, but negative for the progesterone receptor. The nuclei of the spindle and myoepithelial cells were immunoreactive for HMGI-C and HMGI(Y) proteins, indicating a histogenesis similar to pleomorphic adenoma of the salivary glands. Interphase fluorescence in situ hybridization performed on paraffin-embedded tissue sections with 12q15 probes and a 6p21 probe demonstrated no chromosomal rearrangement. Sixty-nine cases of this type of tumor arising in the breast have been described previously. Using imaging procedures, the tumor has occasionally been misdiagnosed as malignant clinically and even pathologically in frozen section diagnosis. Careful diagnosis based on paraffin sections is required to avoid unnecessary aggressive surgery, and pathologists should include pleomorphic adenoma in the differential diagnosis of a demarcated, juxtaareolar, small hard mass.
Department of Pathophysiological and Experimental Pathology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan.
Katsuaki
K
Sato
Yoshimichi
Y
Ueda
Miyako
M
Shimasaki
Mamoru
M
Ozaki
Naoki
N
Nitta
Kiran
K
Chada
Yoshimaro
Y
Ishikawa
Shogo
S
Katsuda
D008949:Adenoma, Pleomorphic / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D005260:Female; D025741:HMGA1a Protein / Q000032:analysis; D025743:HMGA2 Protein / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D017404:In Situ Hybridization, Fluorescence; D008875:Middle Aged; D011960:Receptors, Estrogen / Q000032:analysis
D014408:Biomarkers, Tumor; D025743:HMGA2 Protein; D011960:Receptors, Estrogen; D025741:HMGA1a Protein