The diagnostic use of radiolabeled octreotide has shown that somatostatin receptor scintigraphy can be successfully used in various neoplasms with a strictly neuroendocrine derivation, because of a good correlation between in vitro receptor expression and in vivo uptake. Moreover, 111In-Octreotide uptake has been demonstrated in various pathologies owing to the receptorial expression on cell elements such as lymphocytes, fibroblasts and endothelium. Although main diagnostic role is in neuroendocrine tumours, octreotide can be also used to obtain an immunological imaging in other fields. The presence of type 2 receptors on activated lymphocytes has stimulated the use of somatostatin in both the treatment and diagnosis of disease activity in patients with Graves' ophthalmopathy. Somatostatin analogs have been successfully used for the treatment and imaging of various tumours of thymic origin. Our research group has evaluated the possible clinical role of octreotide scintigraphy in paediatric patients with thymic hyperplasia after chemotherapy for lymphoma. Even if not routinely applicable, these approaches offer interesting diagnostic, prognostic and therapeutic prospects.