Inadequacy of APUD concept in explaining production of peptide hormones by tumours

Small Cell Carcinoma of the Prostate

An 82-year-old man, who 7 years previously had been treated for adenocarcinoma of the prostate, was found to have developed a small cell (oat cell) carcinoma of prostate, which presented with liver metastases. The expression of different neuroendo crine markers in these carcinomas is presented, the histogenesis of small cell carcinoma is discussed, and the relevant literature is reviewed. The importance of the recognition of small cell carcinoma of the prostate is emphasized because of the influence of small cell carcinoma on the prognosis. Int J Surg Pathol 2(3):237-244, 1995

Preliminary evaluation of the usefulness of Tc-99m (V) DMSA in pancreatic neuroendocrine tumors

The authors describe the possible application of Tc-99m (V) DMSA scintigraphy in pancreatic neuroendocrine tumors. In consideration of the common embryonic origin of these tumors and other neoplastic diseases (medullary thyroid carcinoma, pheocromocytoma, neuroblastoma) that have been well studied with radionuclide imaging, five cases of pancreatic neuroendocrine tumors (two insulinomas, one vipoma, and two unclassified neuroendocrine tumors) were successfully visualized with Tc-99m (V) DMSA scintigraphy, thus giving an overall "imaging confirmation" of the histologic and/or cytologic results in terms of primary and metastatic localization. The authors point out the importance of their results, obtained in a simple and repeatable manner, and suggest a real comparison in this setting between this approach and octreotide scintigraphy.

Central and autonomic nervous system links to the APUD system (and their APUDomas)

The concept of the APUD system and the APUDomas associated with it has evolved significantly since Pearse's description in the 1960s. Part of this evolution has been an understanding of the relationships between the APUD system and the central and autonomic nervous systems. The APUD system now referred to as the diffuse neuroendocrine system, can be linked to the central nervous system and autonomic nervous system by genetics, embryology, cellular characteristics, anatomy, interaction of the systems, and the immune system. Awareness of these relationships may enable clinicians to better understand APUDomas and lead to better methods of detection of these tumours and their treatment.

The use of biomarkers in the prediction of survival in patients with pulmonary carcinoma

Data on ten variables and 16 biomarkers were obtained on 119 patients with newly diagnosed pulmonary cancer. The prognostic value of 16 biomarkers (alpha-1-antitrypsin [AAT], adrenocorticotropic hormone [ACTH], alpha-fetoprotein [AFP], carcinoembryonic antigen [CEA], human chorionic gonadotropin [HCG], immune complexes, immunoglobulins, N-terminal peptide of proopiomelanocortin [NTERM], and tumor-associated antibody [TAA]) was tested by adding these to the model of age, gender, stage, morphology, Feinstein's classification of symptoms, Karnofsky scale, leukocyte count, recent weight loss, and liver enzymes. Using Cox's regression method and a forward stepwise procedure, seven biomarkers (ACTH, AAT, AFP, calcitonin, HCG, TAA, and prolactin) entered the model. Elevated levels of cortisol and TAA were associated with longer survival. The selection of biomarkers by stepwise regression needs to be interpreted with caution, especially since the Z scores were found to be dependent on the particular variables included in the model. Furthermore, when dichotomized on maximum of the normal laboratory values, HCG and AFP were infrequently (2%) elevated. The lack of correlation among the biomarkers supports the hypothesis of random derepression of the genome of cancer cells. Further studies in improved modeling and the formulation of a biomarker index could enhance our understanding of the biology of cancer.

Alpha-melanocyte-stimulating hormone immunoreactivity in human melanoma metastases extracts

Seven human melanoma metastases were extracted in order to check the possible presence of any alpha-melanocyte stimulating hormone (MSH) immunoreactivity. The aim of that study was to provide some explanation for, mainly, two observations that we have already made and reported: 1) increased plasma alpha-MSH levels in melanoma of tumour-bearing patients as compared with tumour-free patients; 2) the presence of specific alpha-MSH receptors on human melanoma cells in culture. We could measure large amounts of immunoreactive alpha-MSH in all tumours ranging from 0.31 to 4.27 pmoles per g of wet tissue. Further identification of the extracted material by high-performance liquid chromatography revealed compounds of higher molecular weight and more hydrophobic than synthetic alpha-MSH. In addition, purified extracts could also displace 125I-labelled alpha-MSH from its cellular binding sites in an alpha-MSH specific radio-receptor binding assay. Our findings would suggest a possible presence of some hormone precursor(s) inside the melanoma tumours.

Human gallbladder mucosa ultrastructure: evidence of intraepithelial nerve structures

The zinc iodide-osmium tetroxide (ZIO) fixative-staining method was used along with topographical ultrastructure to investigate cholecystectomized human gallbladders under light and electron microscopic techniques. This method delineated neuronal structures which may be involved in controlling the functions of the gallbladder epithelium. Three epithelial cell types were described in the surface epithelium: 1) Columnar clear cells; 2) dark, tuft osmiophilic cells; and 3) basal clear cells with electron-dense granules and showing intense ZIOphilic staining properties. While mucous granules were delineated in the first two cell types, the columnar epithelial clear cells are of uncertain function(s) and content but are probably absorptive cells. The small basal clear cells displaying intense ZIOphilia are associated with intraepithelial nerve endings. These nerve structures may have a sensory and/or motor function(s); they were detected throughout the gallbladder epithelial lining and mucosa.

Neuroendocrine cell populations in normal human lungs: a quantitative study

Pulmonary neuroendocrine cells, identified by their positive immunochemical reaction for neurone specific enolase, were readily demonstrable and uniformly distributed in 15 pairs of normal adult human lungs. About 65% contained gastrin releasing peptide and nearly all the rest contained calcitonin. Leucine-enkephalin was not found. Serotonin containing cells were few, and cells immunoreactive for adrenocorticotrophin and antidiuretic hormone were absent. About one in 10 cells was argyrophilic, and costorage of peptides was not seen.

Ectopic hormone production by a prostatic small cell carcinoma xenograft line

The xenograft line, UCRU-PR-2, has been characterized further. Established from a primary human undifferentiated small cell carcinoma of the prostate, it has been maintained as a stable xenograft line in nude mice and is currently in passage 9. The tumor has maintained the features of small cell undifferentiated carcinoma but shows epithelial as well as neuroendocrine characteristics. In this paper, we describe synthesis and secretion of peptide hormones, ACTH, beta-endorphin and somatostatin in vivo and ACTH and beta-endorphin in vitro by the tumor, UCRU-PR-2. This suggests that the gene for proopiomelanocortin is expressed and that processing of the molecule occurs. This line may yield insights into the histogenesis of the subtypes of prostate cancer, and also aid studies of regulation of ectopic hormone production.

Immunocytochemical and ultrastructural findings in a mature retroperitoneal teratoma

Report is made of a mature retroperitoneal teratoma in a 32-year-old man. Investigation of the tumor revealed cells immunoreactive for ACTH, Met-enkephalin, beta-LPH, serotonin, FSH, BPP, S100, Neuron-specific-enolase. These cells were mainly present in the glandular epithelium, lining the cysts of the tumor. Ultrastructurally, neuro-secretory granules were demonstrated in the cytoplasm of the tumoral endocrine cells. At no time did the patient display endocrine symptoms.

Sipple's syndrome associated with a large prolactinoma

A 26-year-old male presented with the symptoms and signs of acute congestive heart failure and hypertension. The left ventricle was shown to be thickened and displayed reversible hypokinesia. Further investigations revealed the underlying pathology of a phaeochromocytoma, bilateral medullary thyroid carcinoma (MTC), parathyroid adenoma and macro-prolactinoma. There was a family history of MTC. The echocardiographic features of catecholamine-induced cardiomyopathy were important in this diagnosis. Our research revealed no previous report of Sipple's syndrome associated with a macroprolactinoma. This case, along with the other 13 reports of mixed (type I and II) multiple endocrine neoplasia (MEN), are not within the classical subsets of MEN.

Carcinoid tumor of undescended testis

Carcinoid tumor of the testis is rare and its histogenesis is controversial. We report a case of carcinoid tumor in an undescended testis with electron microscopic evidence of neurosecretory granules.

Malignant carcinoid of oesophagus

This paper presents a unique apudoma variant--a malignant carcinoid of mid and lower oesophagus in an elderly man. It was remarkable in the short duration of the clinical symptoms, its rather easy resectability despite its large size and the local perigastric lymph node metastases. On light microscopy, the neoplasm was composed entirely of atypical but uniform round cells lacking argentaffin and argyrophilic staining, arranged in a carcinoid pattern. On electron microscopy, they exhibited dense-core neurosecretory granules.

Immunohistochemical demonstration of neuron-specific enolase in gynecologic malignant tumors

Gynecologic malignant tumors were studied by the immunoperoxidase method for neuron-specific enolase (NSE). They included 22 argyrophil cell carcinomas of the endometrium, 6 argyrophil small cell carcinomas of the cervix, 21 argyrophil cell adenocarcinomas of the ovary (endometrioid type, 10; mucinous type, 11) and 3 ovarian carcinoids (strumal type, 2; insular type, 1). NSE was demonstrated in all cases of argyrophil small cell carcinomas of the cervix and ovarian carcinoids. On the other hand, NSE was positive only in four cases of endometrial carcinomas with argyrophil cells. Argyrophil cell adenocarcinomas of the cervix and the ovary were immunohistochemically negative for NSE. The current results suggest that argyrophil small cell carcinoma of the cervix, ovarian carcinoid, and some endometrial argyrophil cell carcinomas are related to APUDoma.

The volume of the carotid body and periadventitial type I and type II cells in the carotid bifurcation region of the fetal cat and kitten

The bilateral distribution of carotid body type I cells was investigated in 6 fetuses (gestational age 95%) and 9 newborn kittens (aged 1 day to 4 days) by serially sectioning the carotid bifurcation regions. In most specimens type I cells occurred in close proximity to the wall of the occipital artery or one of its small proximal branches within a division of connective tissue with definable but irregular borders. This combination of type I cells and connective tissue constituted the principal mass of the carotid body. Using an interacting image analysis system, the area of the carotid body in each serial section was measured by accurately contouring its perimeter. The volume of the carotid body was calculated by multiplying the sum of the areas of the serial sections by the thickness of the section. The volume of the carotid body was 0.052 +/- 0.018 mm3 in the fetuses and 0.025-0.117 mm3 in the 1-4 day old kittens. A degree of symmetry in the values for the volume of the right and left carotid body was found. Caudally, and separate from the principal mass of carotid body type I cells, isolated groups of periadventitial type I cells were noted in the connective tissues around the occipito-ascending pharyngeal trunk, origin of the occipital artery and rostral end of the common carotid artery in 7 out of 12 specimens from fetal cats and 11 out of 18 specimens in newborn kittens. The volumes of the periadventitial groups of cells ranged between 25-1,365 micron3 in fetuses and 10-1,351 micron3 in kittens.

Sites of prealbumin production in the human fetus using the indirect immunoperoxidase technique

An indirect immunoperoxidase technique was used to investigate the site of prealbumin synthesis in the human fetus from between 8 and 43 weeks. Prealbumin staining was noted in the A cells of the fetal pancreas, both in the primary and secondary generations of the islets of Langerhans, from as early as 12 weeks gestation. Electron microscopy localized the staining to the cytoplasmic secretory granules. Prealbumin was also present in the gastrointestinal mucosa in cells which had a distribution similar to that of argentaffin cells. Positive staining was noted in the lining epithelium of the renal proximal convoluted tubules, but ultrastructural studies indicated that this was probably related to reabsorption, and not to synthesis.