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OBJECTIVE Large cell pulmonary neuroendocrine carcinoma (LCNEC) is a poorly differentiated and high-grade neoplasm. It is positioned between an atypical carcinoid and small cell neuroendocrine carcinoma of the lung in a distinct family of pulmonary neuroendocrine tumors. The aim of our study was to detect somatostatin receptors in this uncommon malignancy and to evaluate the sensitivity of somatostatin receptor scintigraphy (SRS) in LCNEC staging. METHODS We analyzed data of 26 patients (mean age: 61.5±7.9 years) with histologically confirmed diagnosis of LCNEC, including 18 cases not treated surgically and eight patients after the resection of the primary tumor. SRS was carried out with technetium-99m ethylene diamine-diacetic acid/hydrazinonicotinyl-Tyr3-octreotide (Tc-TOC). A visual analysis of scintigraphic images was done with reference to conventional imaging modalities (computed tomography and bone sicintigraphy). RESULTS SRS sensitivity for the detection of primary lesions, supradiaphragmatic metastases, and infradiaphragmatic metastases was 100, 83.3%, and 0%, respectively. Five out of 13 metastases to the liver appeared on SRS as photopenic foci, visible on the background of physiological hepatic activity. Only one of the nine metastases to the skeletal system was found by SRS with sensitivity as low as 11.1%. The overall SRS sensitivity for the detection of secondary lesions and of all lesions was 54.8 and 62.2%, respectively. CONCLUSION Within a rather large series of LCNEC, the primary tumor showed an uptake of Tc-TOC in all cases, whereas some metastases did show Tc-TOC uptake and some others did not.

Somatostatin receptor scintigraphy (SRS) is useful in diagnosing tumours with increased expression of somatostatin receptors. Lymphoma cells are known to express somatostatin receptors; however, the application of indium-labelled analogues in children is limited. The aim of this study was to investigate whether the technetium-labelled somatostatin analogue, depreotide, may be useful in diagnosing and staging malignant lymphoma in children. Fifteen children (mean age 13.8 years) with malignant lymphoma were studied (eight with Hodgkin's lymphoma and seven with non-Hodgkin's lymphoma). All children were investigated for verification of staging established by other modalities. Imaging was performed 3-5 h after administration of 300-550 MBq (99m)Tc-depreotide. All patients underwent whole-body scan and single-photon emission tomography of the chest and/or abdomen. Images were assessed visually. In all patients, foci of increased tracer uptake were found. The neck and thorax were the most frequent lesion localisations. Abdominal lesions were found in four patients, and bone lesions in three. In two patients, diffusely increased uptake was observed throughout the skeleton (verified as representing bone marrow involvement). In 11 patients, the number of abnormal sites detected by SRS was greater than that detected by CT. Based on radionuclide examination, three children were upstaged and none were downstaged. It is concluded that (99m)Tc-depreotide shows increased accumulation in pathological sites in malignant lymphoma in children. SRS with (99m)Tc-depreotide provides a single-day imaging method with high sensitivity in lymphoma and with all the advantages of a technetium-labelled compound. Further studies are required on the specificity and the possible value of (99m)Tc-depreotide in the follow-up of these patients.