Ductal carcinoma in situ (DCIS) of the breast: Role and features of scintimammography (SM) acquired with a high resolution breast specific gamma camera (BSGC)

Objectives Breast DCIS is a non-invasive malignancy encountered increasingly at screening mammography.Early detection is important because high grade and comedo type DCIS can progress to invasive carcinoma.We retrospectively investigated the role of SM acquired with a BSGC in the detection of DCIS and examined possible associations between scintigraphic features and both mammographic and histopathological findings.

Methods Thirty-three women (41-81 yrs) underwent SM in both cranio-caudal and mediolateral oblique views (600 sec/view) using a high resolution BSGC, starting ten min after i.v. injection of 740 MBq of 99mTc-tetrofosmin.Definitive histological diagnosis was obtained after SM.Scintigraphic features were correlated with Mx and surgical findings; 23/33 patients had a high-grade DCIS, while 10/33 patients had an intermediate or a low grade DCIS.A comedo-type DCIS was present in 27/33 cases.The tumor extension was ≤1 cm in 17/33 cases.

Results SM was positive in 31/33 patients (sens.: 93.9%), including 3 negative at Mx (2 high-grade multifocal comedo DCIS >1 cm and 1 Paget’s disease), and false negative in the remaining 2/33 cases (2 high-grade comedo DCIS of 0.6 and 1.5 cm in size) that were positive at Mx which showed a pattern of microcalcifications.Scintigraphic pattern tended to be patchy, irregular or linear in patients with calcifications at Mx, matching their distribution, while focal uptake with well-delineated contours were seen in patients with masses, opacities or distortions.No differences in scintigraphic features were observed between high-grade and non high-grade DCIS or between comedo and non comedo type DCIS.

Conclusions SM acquired with a high resolution BSGC proved a highly sensitive diagnostic tool in DCIS detection, even in subcentimetric lesions, irrespective of the different histopathological subtype, and with a scintigraphic uptake pattern well correlated with Mx findings.

Research Support 1)Fondazione Banco di Sardegna (Prot.1294/2010.1164). 2)PO Sardegna FSE 2007-2013 L.R.7/200