The role of 111In-octreotide scintigraphy in the detection of APUD tumours: our experience in eighteen patients.

111In-Octreotide scintigraphy has been recently proposed as a sensitive technique for the detection of neuroendocrine tumours, based on the high radiotracer affinity towards the somatostatin receptors expressed by the APUD-system cells. In the present study, a group of 18 patients with carcinoid tumours and gastrointestinal (GI) apudomas was investigated to assess the accuracy of Octreotide scintigraphy in localizing primitive, recurrent or metastatic lesions. Both planar and SPECT studies were obtained 4 hours after the i.v. injection of 111In-Octreotide (111 MBq); planar images were also carried out 24 hours later. In accordance with other authors, the sensitivity of the method was found to be very high (94%) in our group of patients; only in one case of nesidioblastosis was the scintigraphy negative. No differences in sensitivity were observed between the planar and SPECT studies, but the latter provided a better topographic localization of the neoplastic foci. It should be pointed out that in 7 cases (3 primitive, 1 recurrent and 3 metastatic lesions) scintigraphy correctly localized the tumour, when the other morphological techniques, such as echography, computed tomography or magnetic resonance, failed. On the basis of our data, we believe that Octreotide scintigraphy should be the first study performed in the evaluation of patients affected by APUD tumours.

CT, MR imaging and angiography in pancreatic apudomas.

Findings at CT, MR imaging and angiography in 29 patients with pancreatic apudomas are presented. CT and angiography were performed in all the patients, MR imaging in 10. Twenty-five patients underwent laparotomy. The ability of the different imaging methods to localize the primary tumor and detect hepatic metastases was compared. CT and MR imaging depicted the primary tumor in 79% and 88% of the cases respectively, angiography in 72%. Enhancement patterns at CT and signal intensity variations at MR imaging were unspecific parameters regarding different types of tumors. CT and MR imaging were considerably more accurate than angiography in evaluating local tumor resectability. Angiography revealed more numerous small hepatic metastases (< 0.5 cm) than CT or MR imaging, but missed metastases in the left lobe in 5 patients. MR imaging seems promising in localizing and characterizing pancreatic apudomas, but further evaluation is needed before any conclusion can be drawn. At present dynamic incremental CT seems mandatory in the evaluation of pancreatic apudomas. Angiography is of value for preoperative and preembolization vascular mapping, and in localizing small pancreatic apudomas not shown at CT or MR imaging. Faster dynamic thin slice CT scanning and fast-sequence MR imaging may increase the sensitivity of detecting small primary pancreatic apudomas.

Somatostatin analogue therapy in functioning neuroendocrine gut tumors.

The purpose of the workshop was to critically evaluate the use of octreotide in the management of important surgical and gastroenterological conditions. The topics covered included: (1) management of functioning gut neuroendocrine tumors, (2) new approaches to localize these tumors, (3) the place of octreotide in the treatment of variceal bleedings, and (4) the use of octreotide in postoperative conditions. Octreotide therapy has been shown to be effective in the carcinoid syndrome, in which symptom control is achieved in 85% of patients, and reduction in 5-HIAA in 60%. Although tumor regression is rarely seen, prolongation of survival probably occurs. Control of diarrhea has been achieved in 84% of patients with VIPoma treated with octreotide. Similarly, octreotide has been found to provide effective control of the necrolytic, migratory dermatitis seen in glucagonoma. By contrast, insulinomas are more resistant to somatostatin agonist therapy. In the Zollinger-Ellison syndrome, octreotide is effective in alleviating symptoms and in reducing serum gastrin levels. However, its use in this syndrome has been superceded by omeprazole. Radioiodine-labelled octreotide has been very effective in in vivo imaging of neuroendocrine tumors in the abdomen, and is now considered the best available technique for localizing these tumors preoperatively. Intraoperative localization with a hand-held gamma camera is being developed. There is an exciting future possibility to use the technique to deliver therapy to tumors. Octreotide therapy has been shown to be at least as effective as and without the adverse hemodynamic effects of Pitressin in control of variceal hemorrhage. It should be regarded as one of several modalities of therapy in the condition.(ABSTRACT TRUNCATED AT 250 WORDS)

111In-octreotide scintigraphy in oncology.

Various tumors of neuroendocrine origin that have amine precursor and decarboxylation (APUD) characteristics can be visualized in vivo after intravenous injection of the somatostatin analogue [123I-Tyr3]-octreotide. However, the relatively short effective half-life of this compound and the high background of radioactivity in the abdomen are drawbacks in its application. Therefore, an 111In-coupled somatostatin analogue ([111In-DTPA-D-Phe1]-octreotide) was developed. This analogue is excreted mainly via the kidneys, 90% of the dose being present in the urine 24 h after injection. Using 111In-octreotide scintigraphy, 7 out of 7 gastrinomas, 4 out of 7 insulinomas, 1 out of 1 glucagonoma, 3 out of 3 unclassified apudomas, but none out of 18 exocrine pancreatic carcinomas were visualized. Also, 19 out of 19 carcinoids, 15 out of 15 glomus tumors, 8 out of 12 medullary thyroid carcinomas, 6 out of 6 small cell lung carcinomas, 4 out of 4 growth hormone-producing and 6 out of 9 clinically nonfunctioning pituitary adenomas were visualized. Apart from APUD-cell-derived tumors, 111In-octreotide scintigraphy was also successfully applied to visualize breast cancer, lymphomas and granulomas. In 39 out of 50 patients with breast carcinoma, 10 out of 11 patients with non-Hodgkin lymphomas, 3 out of 3 patients with Hodgkin's disease, and 8 out of 8 patients with sarcoidosis, tumor sites accumulated radioactivity during octreotide scintigraphy. In a considerable number of patients with carcinoids and glomus tumors, but also in patients with granulomas and lymphomas, 111In-octreotide scintigraphy revealed more tumor sites than did conventional imaging techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

Accumulation of leucocytes labelled with technetium-99m hexamethylpropylene amine oxime in malignant abdominal tumours.

A total of 343 leucocyte scans labelled with technetium-99m hexamethylpropylene amine oxime were reviewed that had been performed in 338 patients suspected of having abdominal infection or inflammation. There was uptake by malignant abdominal tumours in 10 cases (2.9%), which represents 62.5% of known malignancies at the time of the scintigram. Accumulation was seen in 8 patients with adenocarcinoma of the colon associated with a secondary infection in the tumour or pericolic inflammation. A large tumour that had spread beyond the bowel wall was related to a positive scintigram. Accumulation was also found twice in a malignant fibrous histiocytoma in which bleeding and an inflammatory reaction to necrosis were probably responsible for the uptake. The relevant treatment was delayed for 2 weeks-2 months in 4 patients with adenocarcinoma of the colon in whom the positive uptake was regarded as confirmation of the clinically suspected acute diverticulitis.

Invasive pituitary adenoma presenting with nasal obstruction.

We report two cases of massive invasive pituitary adenoma with the unusual presentation of nasal obstruction. In both cases the diagnosis was only made when the obstructing tissue was removed. Cases reported previously have usually presented with severe focal neurological signs or a long history of neurological symptoms. These two cases are unusual in having minimal neurological deficits despite the extension of tumour into the nasopharynx and the middle and posterior cranial fossae. These extensions were well illustrated by computerised tomography. This unusual presentation is discussed with reference to the literature.

Iodine-123 MIBG imaging in a generalized pancreatic polypeptide-gastrin-serotonin secreting tumor.

The usefulness of radio-metaiodobenzylguanidine (MIBG), a specific radiopharmaceutical agent for scintigraphic imaging and treatment of phaeochromocytoma and neuroblastoma, has been extended to the location of carcinoid tumors. Scintigraphic evaluation with I-123 MIBG in a patient with a histologically proven endocrine tumor (apudoma) of unknown origin with liver and bone metastases is reported. Elevated plasma hormone levels of gastrin, pancreatic polypeptide, and serotonin were found. Tumoral content of these hormones was immunocytochemically confirmed on liver biopsy. I-123 MIBG uptake could be seen in those areas of the liver with deficient lesions in the Tc-99m colloid image with a maximal uptake in a large mass at the level of the left liver lobe. No abnormal uptake could be observed at any other level, which was in contrast with autopsy findings of generalized metastatic disease.

Merkel cell carcinoma.

Merkel cell carcinoma is a rare malignant neoplasm of the skin which is locally invasive and frequently metastasizes to lymph nodes, liver, lungs, bone, and brain. Computed tomographic and pathologic findings in an elderly woman with Merkel cell carcinoma of the buttock and regional nodal metastasis are reported. The presence of calcitonin and neuron-specific enolase within the tumor supports the theory that Merkel cell carcinoma is a neuroendocrine tumor derived from the APUD (amine precursor uptake and decarboxylase) system.

Iodine-131 MIBG scintigraphy of neuroendocrine tumors other than pheochromocytoma and neuroblastoma.

Metaiodobenzylguanidine (MIBG) locates most pheochromocytomas and neuroblastomas. The tracer is concentrated in intracellular storage vesicles by an active process. Many other neuroendocrine tumors of the amine precursor uptake and decarboxylation (APUD) series have hormonal storage vesicles and, thus, the potential to take up [131I]MIBG. A variety of neuroendocrine tumors in 57 patients were studied 1, 2, and 3 days after 0.5 mCi [131I]MIBG. Views from skull to pelvis were obtained. Results of MIBG scans were compared with all available imaging modalities (including plain radiography, liver scan, ultrasound, computed tomography, and angiography) and surgical exploration. The neuroendocrine nature of the tumor was determined by histology, immunohistochemistry, electron microscopy, and the assay of appropriate biogenic amines and peptide hormones. Results were (positive/total cases): carcinoids (four of ten), nonsecreting paragangliomas (three of three), sporadic medullary carcinomas of the thyroid (MCT) (one of five), familial MCT (one of 26), chemodectomas (two of five), oat cell carcinomas (zero of four), choriocarcinoma (one of one), atypical schwannoma (with storage granules) (one of one), Merkel cell skin cancer (one of one), islet cell carcinoma (zero of one). We conclude that a wide range of neuroendocrine tumors show [131I]MIBG uptake; tumors other than pheochromocytomas and neuroblastomas are less often seen scintigraphically, but in certain cases (e.g., carcinoid and nonsecreting paragangliomas) scintigraphy may be useful in depicting the extent and location of disease and may indicate therapeutic potential. Iodine-131 MIBG shows promise in the diagnosis and staging of tumors of varied types.

CT of functioning tumors of the pancreas.

Thirty-three patients suspected of having a functioning tumor of the pancreas were studied with computed tomography (CT); 25 had angiographic studies also. Thirty-one cases were confirmed surgically; the other two were lost at follow-up and were excluded from the series. Of the 31 patients, 21 had insulinomas, five had Zollinger-Ellison syndrome, and five had assorted apudomas. CT was positive in 71% of the cases and negative in 29%; 22.6% of the studies were false negative and 6.4% were true negative. There were no false positives. Of the 21 patients with insulinomas, only one had false-negative CT and angiographic studies, caused by diffuse microadenomatosis. In one patient, two separate lesions of the pancreas were seen and identified correctly on both CT and angiography. All identified lesions smaller than 2 cm were seen only because of a hyperdensity on the enhanced CT scan. Lesions larger than 2 cm were identified either because their size distorted the pancreatic contour or because of their vascularity. The importance of proper CT technique using fast scanners and repeated bolus injections of contrast medium is stressed.

Case report: fourteen-year follow-up of an apudoma of the bile ducts at the hilum of the liver.

A patient presented with a sclerosing tumor at the bifurcation of the main hepatic ducts and was followed for 14 yr after the initial symptoms. Palliative surgery was performed in 1968, followed by a remission of 10 yr. A reintervention in 1979 showed an impressive fibrotic mass that could be extirpated. The patient is again in complete remission for almost 3 yr. A tumor biopsy specimen, obtained at the second intervention, showed an apudoma-type tumor. This was confirmed by a positive Grimelius stain and by immunohistochemical investigation.

Computed tomography and angiography in pancreatic apudomas and cystadenomas.

During a 4-year period 17 patients with pancreatic apudoma and 3 patients with cystadenoma of the pancreas were admitted to this hospital. Computed tomography correctly located 3 of 4 insulinomas examined, while angiography revealed 4 of 8, which indicates that CT may replace angiography as the primary examination of these tumors, and possibly also other types of apudomas. When CT fails angiography may demonstrate a pancreatic tumor, suggesting angiography as a supplementary examination. In cystadenoma sufficient information was obtained at CT.

[Angiographic exploration of a case of a case of adrenal APUD adenoma secreting three hormones: VIP, catecholamines, and somatostatin (author's transl)]. / Exploration angiographique d'un cas d'apudome surrénalien á triple composante hormonale. VIP--catécholamines--stomatostatine.

An APUD adenoma of the right adrenal was discovered in an adult after angiography and compted tomography The tumor had provoked a WDHH syndrome. Selective venous sampling before operation demostrated the presence in the tumor of hormonal secretions (VIP and catecholamines). The patient recovered after excision of the tumor, which contained large quantities of intracellular somatostatin and VIP.