The Reading Room Podcast: A Closer Look at Proliferative Breast Lesions with Atypia and LCIS

Is surgical excision necessary for atypical lobular hyperplasia (ALH)? What imaging findings would suggest observation in cases of atypical ductal hyperplasia (ADH)? How should one approach lobular neoplasia?

These questions and more were addressed in recently published guidelines on proliferative breast lesions with atypia and lobular carcinoma in situ (LCIS).¹ In a recent Reading Room podcast episode, Manisha Bahl, MD, MPH, FSBI, shared her insights on the guidelines that were developed in collaboration between the Society of Breast Imaging, the American Society of Breast Surgeons and the College of American Pathologists.

In cases involving lobular neoplasia, Dr. Bahl said it’s important to distinguish between ALH and classic lobular carcinoma in situ (LCIS) versus pleomorphic and florid LCIS.

“Concordant ALH and classic LCIS generally do not require diagnostic excision. As with ADH, however, most evidence supporting observation comes from mammographically detected lesions, and data for MRI-detected lobular neoplasia remain limited,” noted Dr. Bahl, an associate professor at Harvard Medical School.

Pointing out that ADH lesions have an approximately 29 percent upgrade rate to ductal carcinoma in situ (DCIS) or invasive carcinoma, Dr. Bahl said the guidelines generally recommend diagnostic excision. However, certain imaging findings and rad-path concordance may be considerations for observation, according to Dr. Bahl. She said the imaging criteria may include: no palpable mass; mammographic calcifications only without an associated mass, asymmetry or architectural distortion; focal ADH involving no more than two terminal ductal lobular units; and greater than 50 percent sampling of the target calcifications.

“Multidisciplinary input from radiology, pathology, and surgery is recommended when considering observation. A second pathology review is also recommended to confirm ADH because of diagnostic variability between ADH and low-grade DCIS,” emphasized Dr. Bahl, a breast radiologist affiliated with Massachusetts General Hospital in Boston.

For more insights from Dr. Bahl, listen below or subscribe on your favorite podcast platform.

Reference

1. Nakhlis F, Bedrosian I, King TA, et al. American Society of Breast Surgeons, Society of Breast Imaging, and College of American Pathology 2026 guidelines for the management of proliferative lesions with atypia and lobular carcinoma in situ. JAMA Surg. 2026 Aug 19. doi: 10.1001/jamsurg.2026.3552. Online ahead of print.

(Editor’s note: This podcast was originally published as an episode of Dr. Bahl’s Breast Imaging in Focus series at the following link:https://www.diagnosticimaging.com/view/breast-imaging-focus-key-pearls-new-guidelines-proliferative-breast-lesions-atypia-lcis . )