Upregulation of Somatostatin Receptor Expression in Lactating Breast Shown in 99mTc-HYNIC-TOC Scintigraphy.

A 31-year-old female patient with a 4-year history of multiple endocrine neoplasia type 1 (MEN1) presented with abdominal pain and weight loss that she had been experiencing over the past 6 months. Somatostatin receptor (SSTR) scintigraphy using 99mTc-HYNIC-TOC revealed increased uptake in the known pancreatic neuroendocrine tumor as well as diffuse increased uptake in bilateral lactating breasts. This case highlights physiological upregulation of somatostatin receptor expression in a lactating breast.