Incidental lobular carcinoma scar recurrence at delayed breast reconstruction 6 years after mastectomy

A 48-year-old woman was found to have histological recurrence of lobular breast carcinoma in a mastectomy scar excised routinely during delayed breast reconstruction 6 years after a mastectomy. Prior to the subsequent wide excision of the scar, she requested prophylactic contralateral mastectomy and immediate reconstruction. The scar excision revealed positive resection margins prompting further surgery while the contralateral mastectomy showed previously undetected widely infiltrative lobular carcinoma. It is extremely rare to detect lobular carcinoma in incidental histological specimens and even rarer to encounter it in asymptomatic contralateral breasts following prophylactic mastectomy. This unusual presentation and the implications for mastectomy scar management during delayed reconstruction are discussed.