Noncardiac uptake of technetium-99m sestamibi: An updated gamut

Abstract

A 30-YEAR-OLD Spanish-speaking woman presented with an eight-hour history of substernal chest pain that radiated to the back and down both arms. A previous episode was associated with exertion. An electrocardiogram was performed, which showed ST-segment depression and T-wave inversion in the precordial leads. The chest radiograph, cardiac enzymes, and echocardiogram were normal. An exercise stress study was ordered to evaluate for myocardial ischemia. The patient was exercised using the Bruce protocol 77 for 6 minutes, attaining a maximum heart rate of 151 bpm, 79% of the maximal predicted heart rate (MPHR). The study was terminated because of patient fatigue. An additional 1.5 mm STsegment depression was noted in the inferior leads, leading to a nondiagnostic exercise tolerance test. Two weeks later, a Persantine (DuPont, Manati, PR) Cardiolite (DuPont, Billerica, MA) stress test with single photon emission computed tomography (SPECT) was performed to evaluate myocardial perfusion. The patient was infused with 36 mg of intravenous dipyridamole over 4 minutes, followed by an injection of 26.1 mCi of technetium-99m-sestamibi. The anterior planar image showed abnormally increased uptake of MIBI in the left breast (Fig 1). A left lateral projection was performed that also localizes the intense tracer activity to the left breast (Fig 2). The SPECT images showed normal myocardial perfusion. With an interpreter, we obtained additional clinical history--that the patient was breast feeding her baby from the left breast only. The baby had difficulty feeding from the right breast and had fed exclusively from the left breast for the past few months. To our knowledge, this is the first reported case of MIBI uptake in a lactating breast. The following is an updated version of our previous gamut listing the entities that have shown uptake of MIBI. HEAD