An Unusual Cutaneous Recurrence of Carcinoma in the Mastectomy Bed and Its Imaging Features: A Case Report

BACKGROUND Chest wall recurrences of carcinoma after mastectomy usually involve subcutaneous tissue or the deep muscular layer. Recurrences arising in the skin are rare, and there are few reports of the associated radiologic features. This report presents an unusual case of cutaneous recurrence in the mastectomy bed and demonstrates its radiologic features using sonography and magnetic resonance imaging (MRI). CASE REPORT A 44-year-old woman presented with a palpable lump in the inferomedial area of the right chest wall. Six years ago, she had undergone total mastectomy for ductal carcinoma in situ in her right breast. Sonography showed an indistinct, oval, heterogeneous echoic mass measuring 0.9 cm, confined within the skin layer, corresponding to the palpable lump. A color Doppler sonogram showed minimal, spotted vascularity in and around the mass. Sonography-guided fine-needle aspiration biopsy was performed, revealing multiple clusters of atypical cells, suggestive of ductal carcinoma. On subsequent breast MRI, the mass, measuring 1.3 cm, was again localized to the skin; dynamic contrast-enhanced scans showed a circumscribed margin, oval shape, and rim enhancement (morphology) and slow initial enhancement and persistent delayed enhancement (kinetics). The mass was surgically excised and the pathological examination confirmed the diagnosis as recurrent invasive ductal carcinoma in the dermis. CONCLUSIONS Cutaneous recurrence in the mastectomy bed can manifest as a mass with suspicious radiologic features: indistinct margin on the sonogram and rim enhancement on the MRI. Awareness of such radiologic features may aid in differentiating between the various cutaneous manifestations encountered after mastectomy.