920
Chapter 33
to be encountered when ectopic breast tissue enlarges during
pregnancy or in rare instances of fibroepithelial neoplasms
arising from such tissue.
216
One unusual case in which the
diagnosis was made by FNA involved a 45-year-old woman
with a 3.0-cm subcutaneous lesion on the submammary
(Fig. 33.29). In addition to carcinoma arising in ectopic
breast tissue, the differential diagnosis of a FNA specimen
containing atypical epithelial cells obtained from an axil
lary mass includes a proliferative lesion in ectopic breast and
metastatic carcinoma. Proliferative epithelium is most likely
FIG. 33.27.
Residual breast tissue with carcinoma after
mastectomy.
A:
The patient underwent a mastectomy for
intraductal carcinoma with clear cell features shown here.
B:
Nine years later a chest wall mass contained IDC with
osteoclast-like cells (
arrows
).
C:
Benign breast tissue was
also present.
FIG. 33.28.
Breast tissue in a mediastinal teratoma.
A:
A duct and atrophic lobular glands in fat.
B:
Magnified view of
(A)
.
