Woman With Weight Loss and Abdominal Pain and Fullness
A 35-year-old woman has been losing weight and has had worsening abdominal pain and fullness for the past 2 months. She denies nausea, vomiting, and fever. Medical history is significant only for asthma.
This thin woman is in no distress. Temperature is 37.1oC (98.8oF); heart rate, 82 beats per minute; respiration rate, 14 breaths per minute; and blood pressure, 126/80 mm Hg. Heart and lungs are normal. Bowel sounds are normal, and liver and spleen are both normal size. Palpation of the abdomen suggests the presence of a lesion in the midline: the area is mildly tender, although there is no guarding.
Because of this finding and the patient's weight loss, you order a CT scan of the abdomen. The axial image from this scan reveals a soft tissue density just anterior to the common iliac artery on the right, at the level of the iliac crest (Figure 1). It is located within the mesentery and displaces adjacent bowel.
To obtain more detailed information, you order an MRI scan. On T1-weighted images, the lesion is isointense with muscle (Figure 2); on T2-weighted images, it demonstrates increased signal (Figure 3). The lesion displaces small bowel, as was shown on CT. The MRI findings are nonspecific but are consistent with a mass.
A fine-needle biopsy of the lesion is performed, and carcinoid is diagnosed.
Which nuclear medicine test will you order to confirm the diagnosis and determine the extent of the disease?
WHICH TEST-AND WHY:
Octreotide scintigraphy is the most sensitive examination for carcinoid tumors; its sensitivity is more than 90%-greater even than that of CT. Octreotide( scintigraphy is also useful as an adjunct to anatomic imaging in the identification of pancreatic endocrine tumors, especially insulinomas, gastrinomas, glucagonomas, and somatostatinomas.
In addition, because an octreotide scintigram is a total body scan, it makes a cost-effective total body analysis possible. The extent of the disease dramatically alters management of carcinoid tumors and pancreatic endocrine neoplasms. If these tumors present with clinical symptoms, they often have already metastasized.
What the octreotide scintigram shows. In this patient, the octreotide scintigram revealed a very in tense focal area of increased activity in the midline (Figure 4). This correlated with the abnormality identified on CT and MRI and was consistent with a diagnosis of primary carcinoid tumor. Single-photon emission CT (not shown) confirmed that the lesion was in the anterior aspect of the mesentery. No other focal lesions were identified.
Outcome of this case. The tumor was surgically resected. Three months later, the patient had no symptoms.