Rosen's Breast Pathology, 4e

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Chapter 33

A

B

FIG. 33.24.  Ectopic breast tissue in axilla with invasive carcinoma. A,B: Invasive carcinoma presenting as a distinct axillary mass ( Courtesy: Dr. Alexander Swistel ). B: Poorly ­differentiated ductal carcinoma in ectopic breast tissue in the axilla. C–E: These images are from a single axillary tumor. C: A normal lobule in axillary breast ­tissue. D: ILC in axillary tissue above a lobule. E: Pagetoid LCIS in a duct surrounded by ILC.

and the new primary tumor that arises in residual breast tissue (Fig. 33.27). Surgical treatment for ectopic invasive mammary carci­ nomas is wide local excision and regional lymphadenectomy. Metastases frommammary-type carcinomas that arose in ec­ topic breast tissue have been reported in ipsilateral axillary 189 and groin lymph nodes. 192,195 SLN biopsy has been success­ fully performed in such situations. 201 The choice of the lymph node group most likely to be involved by metastases may be

difficult if, for example, the lesion is located over the ster­ num or the upper abdomen. 209 Mastectomy is not indicated if origin in ectopic axillary breast tissue can be documented and there is no evidence of a separate primary tumor in the breast. Vulvar lesions are managed by partial vulvectomy with SLN sampling and/or ipsilateral groin dissection. Many of these tumors have had an aggressive clinical course, with systemic metastases reported to have arisen from axillary and vulvar lesions. 195 Adjuvant treatment with tamoxifen 191,192 or