BREAST CYTOPATHOLOGY

Ductal Carcinoma 91
Pitfalls and Differential Diagnosis
• Atypical ductal hyperplasia
• Fibroadenoma
• Papilloma/ papillomatosis
Invasive Ductal Carcinoma Not
Otherwise Specified
Clinical Features
Infiltrating duct cell carcinoma not otherwise specified (NOS)
is the most common primary carcinoma of the breast, ranging
from 70% to 80% of all breast carcinomas. It is a heterogeneous
group of tumors that lack characteristics that would
allow their classification as a specific histologic subtype, such
as lobular carcinoma. It occurs most frequently in middleaged
to elderly women and rarely in males. These tumors are
rare in women younger than 40 years of age. Infiltrating duct
cell carcinoma may present as a palpable or nonpalpable
breast mass that may or may not demonstrate clinical signs
of skin and/or nipple involvement. Possible clinical presentations
include hard, fixed mass, “peau d’ orange” skin change,
ulceration, bloody nipple discharge, and inverted or retracted
nipple. Breast carcinoma may also be a solely image-detected
lesion. These lesions can be stellate in appearance or well
circumscribed.
Mammographically, the vast majority of these malig nancies
present with a poorly defined spiculated mass with or without
microcalcifications. Sonographically, the most common features
of malignancy are those of a hypoechoic mass with
irregular borders and an uneven echo texture.
Some of the risk factors for breast carcinoma include an
early menarche, late menopause, diet high in saturated fat,
family history of breast cancer, nulliparity, late first live birth,
and first-degree relative with breast cancer. Mutations of the
BRCA1 and BRCA2 genes are associated with familial breast
cancer at an early age.