Carcinoid apudomas

Meckel's diverticulitis secondary to carcinoid tumor: an unusual presentation of the acute abdomen in an adult

This case reports the concomitant findings of carcinoid tumor within a Meckel's diverticulum presenting as an acute abdomen in an adult male. Most Meckel's diverticula remain asymptomatic throughout life, and symptomatic diverticula are virtually nonexistent in older adults. Meckel's diverticulitis is clinically indistinguishable from acute appendicitis, and abnormal or symptomatic diverticula are generally resected. Surgical treatment of Meckel's diverticula is recommended for children during exploration. However, resection is controversial in asymptomatic adults. Carcinoid tumors are the most common primary tumor of the small bowel. The duration of symptoms before diagnosis varies from 2 to 20 years, and half of all patients have incurable abdominal disease at first-look surgery. Metastatic events occur most commonly in the liver with a generally poor prognosis. Surgical resection is the treatment of choice. Both Meckel's diverticula and carcinoid tumor are rare clinical entities, and carcinoid tumors occurring within a Meckel's diverticulum are even more uncommon. Thus, the natural history is difficult to predict and treatment recommendations vary. Solitary, localized, asymptomatic nodules less than 1 cm are generally managed with diverticulectomy or segmental resection. Larger or multiple lesions require wide excision of bowel and mesentery, and hepatic resection may be required for metastatic disease.

Establishment and characterization of a human carcinoid in nude mice and effect of various agents on tumor growth

The authors have established a long-term tissue culture cell line (BON) derived from a metastatic human carcinoid tumor of the pancreas. The cells have been in continuous passage for 46 months. Tissue culture cells produce tumors in a dose-dependent fashion after SC inoculation of cell suspensions in athymic nude mice. BON tumors, grown in nude mice, are histologically identical to the original tumor; they possess gastrin and somatostatin receptors, synthesize serotonin and chromogranin A, and have a doubling time of approximately 13 days. The antiproliferative effects of the long-acting somatostatin analogue, SMS 201-995 (300 micrograms/kg, t.i.d.), and 2% alpha-difluoromethylornithine on BON xenografts in nude mice were examined. Tumor size was significantly decreased by day 14 of treatment with either agent and at all points of analysis thereafter until the animals were killed (day 33). In addition, tumor weight, DNA, RNA, and protein contents were significantly decreased in treated mice compared with controls. Establishment of this human carcinoid xenograft line, BON, provides an excellent model to study further the biological behavior of carcinoid tumors and the in vivo effect of chemotherapeutic agents on tumor growth.

Gastrointestinal and pancreatic endocrine tumours

The radiological diagnosis and interventional management of neuroendocrine tumours of the gastrointestinal tract and pancreas are challenging, demanding the complete gamut of available resources. Carcinoid tumours are most commonly found in the appendix and small bowel. Barium studies usually disclose a small solitary mucosal or submucosal mass in the distal ileum at times associated with smooth muscle hypertrophy and thickening of the mucosal folds. Intussusception and bowel obstruction may be the presenting finding. Mesenteric involvement may evoke a desmoplastic reaction with rigidity, fixation, angulation and tethering of small bowel loops. Angiography may demonstrate a hypervascular primary neoplasm but more frequently reveals vascular encasement and distortion from the mesenteric desmoplastic reaction. Pancreatic islet cell tumour is best defined radiologically by angiography and computed tomography as a well circumscribed hypervascular mass which enhances with contrast material. Portal venous sampling is of considerable assistance in localizing insulinoma. Metastases from neuroendocrine tumours to lymph nodes and to the liver are usually hypervascular. In the evaluation of the liver by CT scanning prior to contrast as well as dynamic scanning during the bolus intravenous injection of contrast material are necessary. At times the precontrast scan is more revealing. Computed tomography with the catheter in the superior mesenteric artery followed by selective hepatic arteriography is the most accurate combination for the detection of hepatic metastases. Interventional radiological management by sequential hepatic arterial embolization is the treatment of choice for multiple hepatic metastases from neuroendocrine tumours. Thus far, the maximum number of embolic episodes in a single patient has been 13. The carcinoid syndrome has been controlled in 87% while 79% of islet cell tumour hepatic metastases have responded. Contraindications to HAE includes a combination of all of the following: (i) replacement of more than 50% of the liver by tumour, (ii) serum lactic dehydrogenase above 425 mU/ml, (iii) serum glutamic oxaloacetic transaminase above 100 mU/ml, and (iv) bilirubin above 2 mg/dl. In the face of occlusion of the portal vein by intravascular neoplasm, HAE is contraindicated only if portal flow through collateral vein is away from the liver.

Lower extremity vasospasm associated with ischemic neuropathy, dermal fibrosis, and digital gangrene in a patient with carcinoid syndrome

Bilateral lower extremity vasospasm associated with severe pain and hyperesthesias in the legs, and digital gangrene in both feet developed in a 50-year-old man with carcinoid syndrome. Nifedipine and chemical lumbar sympathectomy were partially effective in relieving the vasospasm. Electromyographic findings were consistent with ischemic neuropathy. A skin biopsy specimen showed striking dermal fibrosis. Serotonin and other vasoconstrictor substances released from the tumor may be responsible for the vasospasm, the dermal sclerosis, and the ischemic neuropathy. The early use of lumbar sympathectomy in patients with lower extremity vasospasm may prevent these irreversible ischemic complications.

Carcinoid of the small intestine

Carcinoid tumour was the most common small bowel tumour found in this series of 179 patients. It occurred in 24% of patients. Forty-six percent of patients were asymptomatic during life, the tumours being found either at autopsy or during other surgical procedures. Of those that were symptomatic, half presented with intestinal obstruction and the rest with long-standing symptoms. An abdominal mass, which occurred in 14% of cases, is an uncommon physical finding since the majority present as small submucosal tumors. Fifty-eight per cent overall and 72% of those having surgery had evidence of regional spread, either by local invasion or in the form of regional nodal involvement. Seven per cent of patients have died of their disease. Excisional surgery should be performed for all cases where feasible, and repeated for recurrent symptoms.

Carcinoid tumour of ampulla of Vater associated with viscero-cutaneous neurofibromatosis

A case of carcinoid tumour of the ampulla of Vater with viscero-cutaneous neurofibromatosis is reported together with a review of the literature.

Melanocytic bronchial carcinoid tumor

A melanin- and serotonin-producing bronchial carcinoid tumor is described. Melanin synthesis by neoplastic cells also containing electron-dense core (neurosecretory granules was documented by electron microscopy and serotonin content was found by biochemical assay to be 201.2 micrograms/g wet weight of tissue. Simultaneous demonstration of "endocrine" properties with characteristics of a cell of neural-crest origin provides strongly confirmatory evidence for the APUD cell theory of Pearse and makes an interesting commentary in regard to general theories of neoplasia.

Effect of somatostatin on ion transport in the rat colon

The effect of somatostatin (SRIF) on ion transport was determined in the rat colon in vitro. SRIF produced a sustained decrease in the short circuit current (Isc) (-0.8 +/- 0.1 mueq/h x cm2) and increased net Cl absorption (0.9 +/- 0.3 mueq/h x cm2). The threshold effect of SRIF on Isc was observed at 6 nM. 10 microM serotonin decreased net Na absorption (-2.6 +/- 0.4 mueq/h x cm2), net Cl absorption (-3.6 +/- 0.5 mueq/h x cm2) and increased Isc (0.7 +/- 0.1 mueq/h x cm2); these changes were totally blocked by 0.1 microM SRIF. SRIF completely blocked net Cl secretion induced by 10 mM theophylline (-2.5 +/- 0.7 to +4.1 +/- 2.0 muq/h x cm2) and partially blocked theophylline-induced inhibition of net Na absorption (0.7 +/- 0.5 to 2.1 +/- 0.4 mueq/h x cm2). SRIF also blocked prostaglandin E1 (PGE1) induced increase in potential difference and Isc (P < 0.001). Mucosal cyclic AMP levels were increased by theophylline and PGE1 but not by serotonin. SRIF had no effect on basal or theophylline- and PGE1-stimulated cyclic AMP levels. These results indicate that SRIF blocks both cyclic AMP and noncyclic AMP mediated changes in ion secretion and suggest that SRIF is acting at a step in the secretory process beyond the formation of cyclic AMP.

Bronchial carcinoid metastatic to skin. Light and electron microscopic findings

This case report illustrates the value of ultrastructural examination of an undifferentiated carcinoma mestastatic to skin. In this patient, ultrastructural study of a cutaneous nodule demonstrated cytoplasmic neurosecretory granules characteristic of an amino precursor-uptake and decarboxylation cells (APUD) tumor and supported the diagnosis of metastatic bronchial carcinoid. Additional nine cases of bronchial carcinoids metastatic to skin are also briefly reviewed.

Carcinoid apudoma arising in a glomus jugulare tumor: review of endocrine activity in glomus jugulare tumors

Previous reports of endocrine activity of glomus jugulare tumors have been of pheochromocytomas but not carcinoid apudomas. This paper is to alert the otolaryngologist to the presence of carcinoid apudomas in glomus jugulare tumors. A patient with a long history of explosive diarrhea, facial flushing, and violent headaches, the symptom of carcinoid syndrome, was cured after removal of his large glomus jugulare tumor. The diagnosis of carcinoid syndrome is made with a good history and confirmed with a 24 hour urine collection for 5 Hydroxy indole acetic acid (5 Hiaa). a series of patients treated at the Johns Hopkins Hospital for glomus jugulare tumors is reviewed for the presence of endocrine activity and the literature on endocrine active glomus jugulare tumors is presented. Preoperative evaluation for the presence of both pheochromocytoma and carcinoid apudoma is recommended for all patients with glomus jugulare tumors.