We modeled the probability of upgrade as a function of total abnormal TDLUs, total TDLUs, and percent abnormal TDLUs using univariate and multivariate logistic regression models.
The total number of TDLUs counted in each specimen ranged from 2 to 180 (mean, 47.4).
Middleton and colleagues (31) found that if fewer than 3 TDLUs were involved by ALH/LCIS, the risk of upgrade to cancer was less than 2%, and they concluded that surgery was not necessary in these cases.
In conclusion, we found no added value or utility in quantifying normal and abnormal TDLUs to aid in determining whether to recommend surgical excision or not.
Occult neoplastic epithelial proliferations identified in 4 nipples (Table 1) included primary disease with 1 case of lobular carcinoma in situ involving TDLU in the nipple (Figure 2, A) and 1 case of Paget disease with lesion measuring 0.1 cm (Figure 2, B); and extension of underlying malignancy with 2 cases of pagetoid spread of spatially remote invasive ductal carcinoma (IDC) along lactiferous ducts (Figure 2, C and D).
In this study we analyzed the presence of TDLU as the potential grounds for development of a new malignancy in the preserved nipple, and the frequency of nipple involvement by overt and occult neoplastic epithelial proliferation.
(18) In this view, a high frequency of TDLU in the nipple is of importance in patients undergoing NSM as it serves as a potential source of de novo cancer development in the preserved nipple.
Similar to occult neoplastic involvement, the reported frequency of TDLU in the nipple varies significantly.
In conclusion, around one-fourth of the nipples contain TDLU, which does not depend on the patient's age or hormonal status.