A 58 year old woman underwent a core biopsy of a mass. That case was presented in the Interesting Case Series June 27, 2016, entitled “Reactive or Neoplastic Metaplastic Lesion?"
…..And now for the rest of the story…..
Following the initial diagnosis of low grade adenosquamous carcinoma, the patient underwent a core biopsy of an enlarged lymph node (image 1) as well as a separate breast nodule (core biopsy of second breast lesion not shown).
The patient then underwent lumpectomy (images 2-5), and limited lymph node dissection (image 6).
Image 7-8. Immunohistochemical studies using antibodies to p63 were performed on the lymph node core biopsy (image 7) as well as the lymph node removed at the time of lumpectomy (image 8). Maintenance of myoepithelial cells is present, supporting the histologic diagnosis of benign breast epithelium within the lymph node.
Discussion: Although uncommon, axillary lymph nodes may contain breast tissue, usually in the form of benign glandular inclusions, but occasionally intraductal papillomas may be present (see Interesting Case Series, “a staging paradox’, December 26, 2015". The latter finding occurs most often when the ipsilateral breast contains intraductal papillomas, as occurred in the current case. Recognition of this phenomenon can avoid over-diagnosis of metastasis.
Reference: Boulos FI, et al. Intranodal papillary epithelial proliferations: a local process with a spectrum of morphologies and frequent association with papillomas in the breast. Am J Surg Pathol. 2014 Mar;38(3):383-8.