51 | TRICHOSCOPIC CLUES TO ALOPECIA NEOPLASTICA SECONDARY TO BREAST CARCINOMA: A CASE REPORT

A. Sechi¹, P. Ferrero^1|2, L. Valtellini^1|2, G. Perego^1|2, A. Marzano^1|2 | ¹Dermatology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy; ²Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy

Introduction. Alopecia neoplastica (AN) is a rare form of scalp metastasis that can present as alopecia and may be associated with variable follicular damage leading to cicatricial changes. Breast carcinoma is the most common source of cutaneous metastases in women and may rarely present as AN. Because its clinical features can mimic inflammatory or autoimmune alopecias, diagnosis is often challenging. We report a case of AN secondary to invasive lobular breast carcinoma and highlight the role of trichoscopy.
Materials and Methods. A 57-year-old woman presented with four recently developed alopecic patches on the vertex and parietal scalp. A few weeks earlier she had been diagnosed with invasive lobular breast carcinoma (ER 70%, PR 60%, Ki-67 10%, HER2-negative). Clinical and trichoscopic evaluations were performed, followed by scalp biopsy with histopathological and immunohistochemical analysis. Systemic staging results were reviewed.
Results. Lesions were asymptomatic erythematous patches <1 cm. Trichoscopy showed partial loss of follicular ostia, yellow dots, a milky-red background, polymorphous vessels (arborizing and glomerular), yellow-orange structureless areas, and hair shaft abnormalities including pili torti, broken hairs, and black dots. Based on these findings and the recent breast cancer diagnosis, AN was suspected. Histopathology confirmed cutaneous metastasis of invasive lobular carcinoma with CK7, CK pool, and GATA3 positivity. The immunoprofile matched the primary tumor (ER >90%, PR 70%, Ki-67 3%, HER2-negative). Staging revealed suspicious axillary, internal mammary, and retropectoral lymph nodes and diffuse sclerotic bone metastases. Fine-needle aspiration confirmed metastatic breast carcinoma. The patient started abemaciclib and letrozole. At 1-year follow-up, no progression was observed, with partial regression of scalp lesions but persistent cicatricial alopecia.
Conclusions. We describe a case of AN secondary to breast carcinoma in a patient with a recent diagnosis of invasive lobular breast cancer, in whom metastatic disease was identified during staging. AN should be included in the differential diagnosis of cicatricial alopecia, especially in patients with a history of malignancy. Trichoscopy may provide useful diagnostic clues, including loss of follicular ostia, yellow-orange areas, polymorphous vessels, and hair shaft abnormalities. However, histopathology remains essential for definitive diagnosis. Early recognition may facilitate timely oncologic management.