ARRS Case of the Week- Nov 20, 2017

BREAST IMAGING: Calcifications

Case Author: Jiyon Lee, MD, New York University School of Medicine

History

49-year-old woman participating in surgical consultation after recent ultrasound-guided core biopsy of a new palpable lump in the right lateral breast showed lobular carcinoma in situ, classic subtype; the actual diagnosis and appropriate next step in management must be determined.

Imaging Findings

Photographically enlarged right mediolateral oblique (A) and laterally exaggerated craniocaudal (B) mammograms of the right breast show 6-cm segmental pleomorphic calcifications in the upper outer quadrant. The anterior twist clip is from ultrasound-guided core biopsy of the palpable lump. The posterior twist clip is from stereotactic biopsy performed after the diagnostic evaluation. These calcifications are new compared with the last mammogram, obtained 4 years earlier (not shown). Findings on left mammogram (not shown) were normal.

Ductal carcinoma in situ; surgery
Fibroadenomatous calcifications; follow-up mammography in 6 months
Pleomorphic lobular carcinoma in situ (PLCIS) and classic lobular carcinoma in situ; calcifications associated with PLCIS; surgery
Secretory calcifications in segmental distribution; follow-up mammography in 1 year

Diagnosis

Pleomorphic lobular carcinoma in situ (PLCIS) and classic lobular carcinoma in situ; calcifications associated with PLCIS; surgery

Teaching Points

Lobular carcinoma in situ (LCIS) has historically been regarded as an incidental breast biopsy finding (percutaneous and surgical) and a high-risk marker of future malignancy (ductal or lobular) rather than itself malignant or a precursor of malignancy. Some pathologists recommend use of the term lobular neoplasia (LN) for LCIS and atypical lobular hyperplasia (ALH). Results of more recent molecular studies suggest that LN may also behave as a nonobligate precursor to malignancy. Few reports have described LCIS as the sole histologic entity accounting for imaging findings that led to biopsy, usually calcifications. It is possible, as in this case, that some form of LCIS can be the concordant diagnosis for the imaging finding. Radiologic-pathologic concordance must be carefully assessed to determine management. The pleomorphic LCIS (PLCIS) variant can be indistinguishable from intermediate- and higher-grade DCIS at histologic examination (cellular pleomorphism, comedonecrosis, and microcalcifications). The calcifications in PLCIS can extend into the ducts. The E-cadherin (epithelial cadherin) special stain result is negative in lesions of lobular origin. In contrast to PLCIS, the so-called classic form of LCIS (CLCIS) consists of small, monotonous, and loosely cohesive cells that lack pleomorphism and necrosis. Infrequent calcifications associated with CLCIS may be closer to uniform. There is some controversy regarding management of lobular neoplasia (ALH and LCIS) diagnosed at percutaneous core biopsy. For LCIS, the guidelines established by the National Comprehensive Cancer Network call for excision when LCIS (regardless of subtype) is diagnosed at needle biopsy because of the potential association with malignancy. Although both are uncommon in core needle biopsy specimens, PLCIS is even less common than CLCIS and usually not seen in isolation. The overall reported association of LCIS with malignancy (DCIS or invasive carcinoma) at surgery (upgrade rate) is 10–37%. Invasive carcinoma can be ductal, lobular, or mixed.

Schedules and Media