[Non-palpable lesions of the breast: retrospective clinical study]

A non-palpable breast lesion (NPBL) is a disease of the mammary gland that cannot be detected during clinical examination but that can be visualized by mammography and/or ultrasonography, either during screening programs or sometimes in asymptomatic women. These small lesions require an adequate diagnostic-therapeutic approach to ensure correct treatment. The aim of the present study was to analyse a series of NPBLs retrospectively in order to define them nosologically and establish an adequate diagnostic-therapeutic work-up for such cases. Ninety-three patients with a total of 99 NPBLs were observed from January 1989 to December 1999. The 99 NPBLs were submitted to ultrasonography and 31 (31.3%) were also submitted to US-guided fine needle aspiration biopsy (FNAB). Later on the diagnostic-therapeutic procedure involved surgical biopsy after radiological centering and, in the case of malignant neoplastic lesions, surgical intervention and adjuvant therapy. Ultrasonography confirmed the presence of NPBL in 45 cases of the 99 detected at mammography (45.4%). Cytological examination of the 31 FNABs yielded the following results: unreliable 19.3%, suspected malignancy 42%, negative for neoplastic cytology 6.5%, positive for carcinoma 32.3%. The histological diagnosis was one of mammary carcinoma in 41 patients (43%). Among the 41 carcinomas there were 8 (19.5%) carcinomas in situ, 24 (58.5%) invasive ductal carcinomas, 8 (19.5%) invasive lobular carcinomas, and 1 (2.5%) medullary carcinoma. In the 32 (80%) patients submitted to lymphadenectomy for 33 invasive carcinomas, 6 patients (18.7%) presented positive lymph nodes (N1). The Authors conclude that NPBLs are an important clinical entity because they may be the expression of a malignant lesion; most NPBLs are diagnosed during screening programs or sometimes in asymptomatic women by means of mammography, which is the only standardised method for their identification. The poor diagnostic capability of non-invasive methods and the potential malignancy of NPBL justify the indication for surgical excisional biopsies; in cases of histological findings of malignancy it is often possible to perform conservative surgery with similar results to radical surgery in terms of survival. When NPBLs turn out to be invasive carcinomas, a concomitant lymphadenectomy is mandatory.