Objective: The aims of our study were to determine the frequency of malignancy after surgical excision of biopsy-proven lobular carcinoma in situ (LCIS) or atypical lobular hyperplasia (ALH) lesions, to assess any difference between pure LCIS and pure ALH lesions regarding their radiologic presentation and the malignancy upgrade rate after surgical excision, and to evaluate the outcome of lesions that were not excised surgically but were followed up.
Materials and methods: Radiologic and pathologic records of 14,435 imaging-guided needle biopsies of the breast performed between 2004 and 2008 in three different institutions were retrospectively reviewed. A total of 126 patients (0.9%) had biopsy-proven LCIS or ALH, or both, as the highest-risk lesion. Among the 126 patients, 89 (71%) continued to surgery, and 14 were followed up for more than 24 months. The Mantel-Haensel chi-square test was used for statistical analysis.
Results: Cancer upgrade was documented in 17 of the 43 LCIS (40%), 11 of the 40 ALH (27%), and two of the six combined ALH and LCIS lesions (33%) surgically excised, for a total malignancy upgrade rate of 34% (30/89). Both LCIS and ALH lesions presented mammographically in most cases as microcalcifications (p = 0.078). None of the 14 patients followed up for a mean period of 51 months showed development of malignancy.
Conclusion: No statistically significant difference was found between mammographic presentation and postsurgical outcome of LCIS versus ALH lesions. Surgical excision of these lesions is recommended as long as no evident criteria are provided to differentiate those that might be associated with an underlying malignancy.