Somatostatin receptor imaging may establish the neuroendocrine nature of unclarified metastases

Traditionally, functional imaging with somatostatin receptor analogues is used in the primary diagnostics, staging, and monitoring of neuroendocrine tumors (NETs) as well as to asses the potential effect of treatment with (radioactive) somatostatin analogues. We report a case in which a woman was diagnosed with a low grade NET in a liver biopsy, but results from the diagnostic work-up pointed towards a synchronous, high grade, metastasizing malignancy. Because of the patient’s poor general health, invasive procedures were deemed unattainable. Somatostatin receptor scintigraphy with the tracer 111 In-pentetreotide was therefore used as a very specific method of establishing the neuroendocrine nature of all the lesions found, and hence, palliative treatment could be commenced. This case thereby illustrates the feasibility of using somatostatin receptor imaging to establish the neuroendocrine nature of metastases suspected of originating from a synchronous high grade malignancy, when a low grade neuroendocrine tumor has been diagnosed elsewhere and invasive procedures are not possible.