Clinical and pathologic features of fibroadenoma of the mastopathic type.
OBJECTIVE
Fibroadenoma with mastopathic change (FAM) is a relatively uncommon subtype of fibroadenoma of the breast, with a high incidence of pathological misdiagnosis. This histological subtype remains poorly understood because of its rarity. Many questions remain unanswered about its clinicopathological importance, especially in the differential diagnosis of breast cancers.


METHODS
Among 218 breast fibroadenomas surgically resected as excisional biopsies at our institute between 1990 and 2004, 19 were pathologically diagnosed as FAM. We reviewed these 19 patients.


RESULTS
The ages of the patients ranged from 20 to 51 years (mean 36.8 years). The tumor sizes ranged from 0.8 to 7 cm (mean 2.1 cm). Six of the 19 patients underwent core needle biopsy, resulting in a diagnosis of fibroadenoma in four patients and atypical ductal hyperplasia in two patients. Ultrasonography showed findings suggestive of solid tubular carcinoma in seven patients, fibroadenoma in ten patients, and unspecific malignant tumors in two. They were not specified clinically.


CONCLUSIONS
Recognition of this distinctive variant of fibroadenoma is important because it resembles intraductal carcinoma and is increasing in incidence. It is crucial to distinguish FAM from intraductal carcinoma in biopsy specimens. Thus, not only pathologists but also clinicians must be able to recognize this type of fibroadenoma, and cooperate closely to establish an accurate diagnosis.
Kuroda
Hajime
H
Department of Pathology, Saitama Medical Center, Saitama Medical School, 1981 Tsujido, Kamoda, Kawagoe, Saitama, Japan.
Takeuchi
Ikuya
I
Ohnishi
Kiyoshi
K
Sakamoto
Goi
G
Akiyama
Futoshi
F
Toyozumi
Yasuo
Y
Momose
Shuji
S
Tamaru
Jun-Ichi
J
Itoyama
Shinji
S
D000328:Adult; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D044584:Carcinoma, Ductal / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D018226:Fibroadenoma / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008875:Middle Aged; D014463:Ultrasonography