Intramammary lymph node involvement by mycosis fungoides diagnosed by fine-needle aspiration biopsy

We report on a case of a patient with diagnosis of mycosis fungoides (MF) who subsequently developed enlargement of the intramammary lymph nodes, which were demonstrated to be involved by tumor on fine-needle aspiration (FNA) cytology. The patient was a 66-yr-old female who had recently noticed the appearance of circumscribed bilateral breast nodules. A mammographic study showed clearly outlined nodules of low density. FNA showed atypical small and large lymphocytes with cerebriform appearance, consistent with intramammary lymph node infiltration by MF. To our knowledge this is the first report of intramammary palpable lymph nodes involved by MF and confirmed by FNA. This case provides support for the use of fine-needle aspiration biopsy as an accurate method for staging MF successfully.