Posterior Approach Partial Mastectomy (MAPP): Early Clinical Experience with a Novel Oncoplastic Technique

Background: Oncoplastic breast surgery aims to combine oncologic safety with optimal cosmetic outcomes. However, many established techniques require visible anterior breast incisions or substantial tissue rearrangement, which may compromise cosmetic results in selected patients. Posterior access to the breast through the retromammary space may allow tumor excision while preserving the anterior breast envelope. Methods: We report an early clinical experience with Posterior Approach Partial Mastectomy (MAPP), a breast-conserving technique that accesses the lesion through a concealed inframammary or lateral breast crease incision. This single-center retrospective case series included consecutive patients undergoing excision using this approach. Patient selection, surgical technique, and early outcomes—including margin status, complications, and need for re-excision—were evaluated. Results: Eight patients underwent breast-conserving excision using the MAPP technique. Six patients had malignant lesions (invasive ductal carcinoma with or without ductal carcinoma in situ or pure DCIS), while two benign lesions were included for technical completeness. Tumor size ranged from 9 to 78 mm. All malignant cases achieved negative surgical margins (R0), and no patient required re-excision. Posterior access was successfully achieved in all cases using concealed inframammary or lateral crease incisions. One patient experienced minor wound discharge that resolved with conservative management, and no major postoperative complications were observed. Follow-up ranged from 2 to 12 months. Conclusions: Posterior Approach Partial Mastectomy appears to be a feasible oncoplastic approach with encouraging early oncologic outcomes in carefully selected patients undergoing breast-conserving surgery. By preserving the anterior skin envelope and concealing the surgical incision, this technique may offer cosmetic advantages while maintaining oncologic adequacy. Larger studies with longer follow-up are needed to further define its role in oncoplastic breast surgery.