Immunohistochemical localization of chromogranin in human hypophyses and pituitary adenomas

Chromogranin was demonstrated by immunohistochemistry in the cytoplasm of human beta-thyrotropin, human beta-follicle-stimulating hormone-, human beta-luteinizing hormone-, and human alpha-subunit-containing cells of the non tumorous human adenohypophyses. Some surgically removed human beta-thyrotropin-, human beta-follicle-stimulating hormone-, human beta-luteinzing hormone-, and human alpha-subunit-producing pituitary adenomas, as well as some null cell-adenomas, exhibited chromogranin immunoreactivity, whereas adenomas storing human growth hormone, human prolactin, or corticotropin were negative. Chromogranin immunopositivity was variable in extent and intensity; not every glycoprotein-producing cell could be immunostained in the nontumorous adenohypophysis and the majority of chromogranin-containing adenomas showed only focal positivity. No explanation can be offered for this variability. The demonstration of chromogranin by the avidin-biotin-peroxidase technique may be helpful in the immunohistochemical characterization of some glycoprotein hormone-producing pituitary adenomas, as well as null-cell adenomas of the human pituitary.     

Pituitary adenomas producing growth hormone in acromegalic patients.

Growth hormone was shown in histological sections of 25 pituitary adenomas from acromegalic patients by means of the unlabelled peroxidase-antiperoxidase (PAP) technique. On the basis of the numbers of cytoplasmic granules, the cells of the adenomas were of two types: densely granulated and sparsely granulated. The densely granulated cells had abundant cytoplasm containing numerous granules, whereas the sparsely granulated cells had little cytoplasm with scanty granules. Depending on the predominant cell type the adenomas were also classified as densely granulated or sparsely granulated: 21 of the 25 adenomas (84%) were densely granulated and four (16%) sparsely granulated. There was some variation, however, in the relative numbers of the two types of cell from one part of an adenoma to another, a feature consistent with one type of cell in different phases of activity. There was no significant difference in mean serum growth hormone concentrations between the two groups, and granularity of the adenomas in histological sections did not therefore correlate with secretory activity. Nine adenomas showed extrasellar extension. The mean serum growth hormone concentration in these cases was lower than the mean of the adenomas confined to the sella turcica. Thus the size of the tumour did not correlate with the serum growth hormone concentration. Three of the four adenomas in the sparsely granulated group showed extrasellar extension, compared with 6 of 21 classified as densely granulated. This suggests that sparsely granulated adenomas have a more aggressive pattern of behaviour, but histological evidence for this was lacking.     

Null cell adenomas of the pituitary gland. An immunohistochemical study

Fourteen null cell adenomas of the pituitary gland were examined immunohistochemically with antisera against three general neuroendocrine markers and 22 hormones. All cases showed positive immunostaining for neuron-specific enolase, ten cases for synaptophysin, and six cases expressed chromogranin immunoreactivity. Hormone immunoreactivity was detected in a few cells in ten of the 14 cases studied and the number of hormones demonstrated in each case was one or two. Thyroid-stimulating hormone was detected in five of the 14 cases, gastrin in four, beta-endorphin in two, calcitonin gene related peptide in one, prolactin in one, and follicle-stimulating hormone in one.     

Lobular capillary hemangioma. An immunohistochemical study including steroid hormone receptor status.

Twenty-one lobular capillary hemangiomas (LCH), including lesions from six pregnant patients, were examined by immunohistochemical analysis. Antibodies to estrogen and progesterone receptor proteins were used to determine whether these steroid hormones play a direct role in LCH development and growth. All 21 LCHs were negative for both receptor proteins. Contrary to the association of LCH with pregnancy and oral contraceptive use, the absence of these steroid receptors strongly suggests that estrogen or progesterone are not directly involved in the formation of these lesions. All 21 LCHs were stained with Ulex europaeus lectin and with a panel of antibodies directed against cytokeratin, vimentin, Factor VIII, collagen Type IV, and muscle-specific actin. Endothelial cells in LCH, both in cellular proliferations with poorly formed lumens and in well-formed capillaries, were labeled by Factor VIII, Ulex europaeus lectin, and vimentin. A population of concentrically arranged, perivascular spindle-shaped cells was highlighted by positive staining for muscle-specific actin, collagen Type IV, and vimentin. The spindled cells were associated with both well-developed and immature vessels in all lesions. The appearance, immunophenotype, and location of these cells is consistent with a pericytic origin. Although the intimate association of both endothelial cells and pericytes suggests a reactive, as opposed to neoplastic, origin, other benign vascular tumors traditionally considered neoplastic have a similar bicellular composition. Accordingly, the findings neither support nor refute a neoplastic origin for LCH.     

Histologic localization of terminal complement complexes in renal diseases. An immunohistochemical study

Histologic localizations of terminal complement complexes (TCCs) were examined and compared with clinical findings in 154 patients with various renal diseases. Immunohistochemical demonstration of TCCs was carried out on ethanol-fixed paraffin-embedded renal biopsy specimens by indirect immunoperoxidase technique. In glomerular diseases that are thought to be immune-complex glomerulonephritis (IC-GN), such as IgA-nephropathy, membranous nephropathy, and systemic lupus erythematosus (SLE), TCCs were demonstrated in a pattern similar to that of immunoglobulins and C3, indicating that TCCs were induced by immune complexes. The intensity of TCC deposition was correlated with the morphologic destruction of glomeruli or serum creatinine levels in IgA-nephropathy, with urine protein in membranous nephropathy, and with serum C4 in SLE. TCC deposits without IC were also observed in tissue damages without disease specificity such as glomerular or vascular sclerosis and tubulointerstitial lesions. These findings suggested the existence of various roles of TCCs in renal injury, according to IC-mediated or non-IC-mediated mechanism acting in individual diseases.     

Alpha-fetoprotein localization in pure ovarian teratoma. An immunohistochemical study of 12 cases

Twelve cases of pure ovarian teratoma were studied by immunohistochemical methods to determine the incidence and localization of alpha-fetoprotein (AFP) production. There were six mature teratomas (grade 0) and six immature ones (grades 1-3). Three tumors (grades 1, 3, and 3 and stages III, I, and III, respectively) had isolated foci of AFP immunoreactivity in yolk-sac-like vesicles, intestinal-type epithelium, or tissue resembling liver, whereas the other nine tumors had no AFP-positive components. The former three patients had preoperative serum AFP determinations; the values were elevated in two of them, and in both instances the oncofetoantigen became undetectable one month after oophorectomy. Both patients are alive and well 15 and 25 months later; the third patient with a normal serum AFP before surgery and a positively stained tumor died of recurrent disease. The authors' findings indicate that the production of AFP in pure ovarian teratomas recapitulates its pattern of synthesis during ontogeny. Furthermore, it is suggested that a preoperative elevation of serum AFP in a pure ovarian teratoma does not seem to correlate with stage or grade, beyond minimizing the possibility that the tumor is grade 0, or mature.     

Pituitary adenomas producing growth hormone, prolactin, and one or more glycoprotein hormones: a histologic, immunohistochemical, and ultrastructural study of four surgically removed tumors

The morphologic features of four pituitary adenomas, removed from 2 men and 2 women between 31 and 62 years of age, are reported. The tumors contained growth hormone (GH), prolactin (PRL), and one or more glycoprotein hormones--usually thyrotropin (TSH). Three tumors were associated with acromegaly and one with hyperprolactinemia. Hyperthyroidism was not evident in any of the patients. In the tumors of acromegalic subjects, GH-containing cells were the most numerous, whereas PRL cells were dominant in the adenoma accompanied by hyperprolactinemia. Electron microscopy revealed plurimorphous tumors comprised of various proportions of morphologically different cell types: densely granulated GH cells, TSH-like cells, and the less common mammosomatotrophs and PRL cells. It is suggested that pituitary adenomas producing GH, PRL, and glycoprotein hormones derive from the same precursor; their immunocytochemical profile, fine structural appearance, and endocrine function may depend on the degree and direction of the cellular differentiation.     

Histologic and immunohistochemical study of clinically non-functioning pituitary adenomas

Seventy-five clinically non-functioning pituitary adenomas were characterized in terms of their histologic and immunohistochemical features. Fourteen adenomas (18.7%) were positive for hormones other than gonadotropins. These included two somatotroph adenomas, three lactotroph adenomas, four thyrotroph adenomas, four corticotroph adenomas and one unusual plurihormonal adenoma. Fifty-five adenomas (73.3%) were exclusively positive for one or more gonadotropin subunits (β-follicle stimulating hormone, p-luteinizing hormone, and α-subunit of glycoprotein hormones), but negative for other hormones such as growth hormone and β-thyrotropin. Histologically, a papillary arrangement along the capillary was most characteristically observed in the gonadotropin-positive adenomas. Five of six adenomas negative for any pituitary hormones exhibited the typical papillary structure. Thus, approximately 80% of clinically non-functioning adenomas constituted a single tumor group that shared the common histologic features of gonadotroph adenomas. These findings suggest that nearly all tumor types of clinically non-functioning adenomas can be diagnosed solely by light microscopy in combination with immunohistochemistry, and that the vast majority of them may be gonadotroph adenomas.     

Immunocytochemical localization of parathyroid hormone in bovine parathyroid glands and human parathyroid adenomas.

Light and electron microscopic localization of parathyroid hormone (PTH) in human and bovine parathyroid tissue has been achieved using an indirect peroxidase labeled antibody method. Granular deposition of the reaction product was found throughout the chief cell cytoplasm. There was no nuclear staining. At the ultrastructural level, parathyroid hormone localized by this method appeared to be largely confined to the secretory granules in the cytoplasm of cells. Mitochondria and nuclei were free of reaction product. Aggregated sacs of granular endoplasmic reticulum were minimally reactive, and Golgi apparatuses did not show reaction product.     

Expression of pan-neuroendocrine proteins in 53 neuroblastic tumors. An immunohistochemical study with neuron-specific enolase, chromogranin, and synaptophysin

The presence and distribution of pan-neuroendocrine markers such as neuron-specific enolase (NSE), chromogranin (CG), and synaptophysin (SYP) were investigated by immunohistochemistry in 53 cases of neuroblastic tumors, including three cases of ganglioneuromas, 17 ganglioneuroblastomas, and 33 neuroblastomas. In ganglioneuromas, all three markers were observed both in ganglion cells and in neurofibrils. All cases of ganglioneuroblastoma were positive for these markers, however, some variability of staining intensity was noted. Of the 33 cases of neuroblastomas, all were positive for NSE, 23 (70%) for CG, and 31 (94%) for SYP. Neuron-specific enolase was detected not only in the majority of the neuroblasts showing signs of differentiation, but also in some undifferentiated neuroblasts. Chromogranin was found mainly in differentiated neuroblasts with enlarged cytoplasm and nuclei, but was scarcely found in undifferentiated cells. Synaptophysin was detected in some undifferentiated neuroblasts, as well as in differentiated neuroblasts. Two cases without SYP-positive cells were also negative for CG. Our observations conclude that antibodies against NSE and SYP are helpful as a diagnostic aid for neuroblastic tumors.     

Pituitary adenomas in Cushing's disease. A histologic, ultrastructural, and immunocytochemical study.

Twenty-two pituitary adenomas in Cushing's disease were removed by transsphenoidal surgery. In six patients the pituitary tumor had become manifest following adrenalectomy (Nelson's syndrome). Sixteen tumors were microadenomas measuring from 2 to 9 mm, while two were diffuse invasive adenomas verified at postmortem examination. Light microscopy showed that the tumors were made of basophillic cells containing PAS-positive granules that stained blue with Herlant tetrachrome and lead hematoxylin. Immunocytochemical studies showed that the granules stained positively with antiserum to adrenocorticotrophic hormone (ACTH) or to beta-lipotropic hormone (beta-LPH) and the peroxidase-antiperoxidase complex. Electron microscopic study of the tumor cells showed ACTH and beta-LPH containing granules varying in size, shape, and amount. Perinuclear bundles of 70 A microfilaments constituted a specific ultrastructural finding.     

Epithelioid sarcoma. An immunohistochemical study

The immunohistochemical findings in 14 epithelioid sarcomas, neoplasms of uncertain histogenesis, indicate that they react with antibodies against cytokeratin, epithelial membrane antigen, and vimentin. All cases were nonreactive for leukocyte common antigen, myoglobin, and Factor VIII-related antigen. These results point to the fact that epithelioid sarcoma expresses phenotypic characteristics more often associated with epithelioid neoplasms, rather than the mesenchymal profile of most soft tissue sarcomas. One explanation for this observation is that epithelioid sarcoma is in fact a carcinoma originating in the deep soft tissues. On the other hand, the pluripotential mesoderm has a known embryonic capacity to differentiate into epithelium and, therefore, it is plausible that epithelioid sarcoma is a mesenchymally derived neoplasm. Aside from histogenetic considerations, epithelioid sarcoma may be confused with a number of other neoplastic and granulomatous processes. Differential immunohistochemical stains are useful in selected instances wherein light and electron microscopic findings are diagnostically equivocal.     

Sessile serrated adenomas of the large bowel. Clinicopathologic and immunohistochemical study including comparison with common hyperplastic polyps and adenomas

Sessile serrated adenoma (SSA) is a newly characterized type of the large bowel adenoma. It arises in hyperplastic polyp (HP) and represents a precursor lesion of colorectal carcinoma with microsatellite instability. SSAs differ from common HPs by abnormal proliferation of the crypt epithelium and by nuclear atypia. We examined 15 SSAs from 15 patients. The age range was 25-80 years (average 60 years). Six patients were females and 9 were males. For comparison, we examined 10 conventional tubular adenomas and 10 common HPs with vesicular cells. The sites of SSAs were as follows: 8 in rectum, 4 in rectosigmoid colon, 1 in transverse colon, 1 next to mucinous carcinoma of ascending colon, 1 in anastomosis after resection of the transverse colon adenocarcinoma. The diameter of the lesions ranged from 5 to 12 mm. Histologically, SSAs showed asymmetrical proliferation of the epithelium, irregular shape of the crypts with their branching and some crypt dilatations especially in the basal parts of the crypts. Cellular atypia (dysplasia) was usually low. In 5 cases the nuclei were focally stratified and localized in the lower part of the cells. High-grade dysplasia was found only in SSA adjacent to mucinous adenocarcinoma. Immunohistochemically, SSAs showed secretion of gastrointestinal mucin expressing MUC2 and MUC5A. Both MUC2 and MUC5A were also positive in mucinous carcinoma. In previous studies these expressions were considered specific for serrated type of carcinogenesis. However, our study found positivity of MUC2 and MUC5A also in conventional adenomas. Expression of p53 in SSAs was minimal. SSAs have malignant potential comparable with conventional adenomas and for this reason they must be distinguished from HPs.     

Capillary hemangioblastoma. An immunohistochemical study

Previous studies using immunohistochemical methods to determine the presence of glial fibrillary acidic protein (GFAP) and Factor VIII-related antigen (FVIIIR:Ag) in stromal cells of capillary hemangioblastomas have yielded conflicting results with respect to the possible astrocytic and endothelial origins of these cells. This study included Ulex europaeus I lectin (UEAI), a more sensitive marker of endothelial cells. Antibodies were also used as markers of pericytes and a variety of markers were employed to identify different populations of histiocytes. Results of this investigation indicate that FVIIIR:Ag and UEAI are limited only to endothelial cells, and that GFAP is present in entrapped astrocytes only. Positivity of stromal cells was found with some of the histiocytic markers, but the authors were unable to conclude that these cells have a histiocytic origin. It was concluded that currently there is no evidence that stromal cells are derived from endothelial, pericytic, or astrocytic cells-their origin remains uncertain.     

Mesenchymal chondrosarcoma. An immunohistochemical study

Mesenchymal chondrosarcoma is an uncommon small-cell neoplasm of bone and soft tissue, the chondrogenic nature of which has been generally accepted. However, the phenotypic attributes of the small-cell population in this neoplasm have not been well characterized, and its relationship to "precartilage mesenchyme" remains unclear. In an attempt to address this issue, we performed an immunohistochemical analysis of nine cases, using antibodies to vimentin, S100 protein, Leu-7 antigen, neuron-specific enolase, synaptophysin, desmin, muscle-specific actin, cytokeratin, and epithelial membrane antigen, and the avidin-biotin-peroxidase complex (ABC) method. The small cells of mesenchymal chondrosarcoma failed to express S100 protein, whereas all components of the tumors (small cells, lacunar chondroblasts, and chondroid matrix) stained for Leu-7 antigen in six cases. Neuron-specific enolase was identified in the small cells of four cases and in the lacunar cells of seven. None contained desmin, actin, cytokeratin, epithelial membrane antigen, or synaptophysin. The immunophenotype of mesenchymal chondrosarcoma resembled that of embryonic cartilage and thus did not contradict the premise that this tumor was the neoplastic counterpart of fetal chondroid tissues. However, immunohistologic studies are not overly helpful in the differential diagnosis between mesenchymal chondrosarcoma and other small round cell lesions.     

Glomus tumours. An immunohistochemical study

The histological and immunohistochemical features of 20 glomus tumours (glomangiomas) were studied retrospectively in routinely processed material. The tumours came from 18 patients (9 women and 9 men, aged 25 to 80 years); two were recurring lesions. Twelve were classified as solid glomus tumours, eight as glomangiomas. Small nerve fibres were present in all except one. A variable number of mast cells were found in the stroma. The glomus tumour cells were negative when stained for Neuron-Specific Enolase, Glial Fibrillic Acidic Protein, S-100 Protein, Chromogranin, or with the Ulex Europaeus Lectin type 1. Conversely, all were found to be positive for Actin, Myosin, and Vimentin. Four exhibited an equivocal reaction for Desmin, the rest were negative. This immunohistochemical profile is in accordance with the findings of other investigators and can be helpful in differential diagnosis. It also shows the glomus cell to be related to smooth muscle cells and pericytes. The majority of these lesions are probably hamartomas, but a few may be true neoplasms.     

The course of neuroendocrine differentiation in prostatic carcinomas. An immunohistochemical study testing chromogranin A as an "endocrine marker"

To gain further insight into the pathogenetic aspects of neuroendocrine (NE) differentiation in prostatic carcinoma, the incidence of NE manifestations was studied during tumour progression in the course of the disease. This follow-up took the form of semiquantitative assessment of the NE cells in carcinomas by means of repeat biopsies at intervals of a few years, correlating the findings with those of conventional histopathological grading of the prostatic tumours. Immunoreactivity to chromogranin A (ChrA) and the Grimelius silver-staining technique were used to detect NE cells. A strong correlation was observed in all the 25 carcinomas studied between the results obtained with the Gimelius silver-staining and those obtained on the basis of immunoreactivity to ChrA. In addition, cells immunoreactive to an antiserum against ChrA found in virtually all sections from 24 cases of hyperplastic prostatic glands were found to be almost invariably argyrophil. Most of the 25 carcinomas underwent marked tumour progression, while the number of NE cells concomitantly increased. An unequivocal relationship can be stated between the degree of NE differentiation and tumour progression in our series of prostatic carcinomas treated with steroids-i.e., the more anaplastic the prostatic carcinoma, the more numerous are its NE cells. ChrA may be considered to be a sensitive marker for NE cells both in hyperplasia and in prostatic carcinomas.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pancreastatin secretion by pituitary adenomas and regulation of chromogranin B mRNA expression.

Pancreastatin, a carboxyl-terminal amidated peptide derived from chromogranin (Cg)A, inhibits secretion of insulin and parathyroid hormone. Our recent studies found significant amounts of immunoreactive pancreastatin in all pituitary adenomas except prolactin adenomas. To analyze the effects of pancreastatin on pituitary cell function, 17 cultured pituitary adenomas were examined for immunoreactive pancreastatin and pancreastatin secretion by the tumors. The effects of pancreastatin on pituitary hormone secretion and on pituitary hormone (follicle-stimulating hormone and prolactin), CgA, and CgB mRNA levels were also examined. Immunoreactive pancreastatin and CgA were present diffusely in gonadotroph and null cell adenomas, but only a few prolactin adenoma cells expressed pancreastatin or CgA. When cells were treated with hypothalamic peptides, gonadotroph adenomas were the only group that released increased amounts of pancreastatin in response to gonadotropin-releasing hormone (10(-7) mol/L). Pancreastatin (10(-7) mol/L) treatment did not stimulate pituitary hormone secretion significantly. In situ hybridization analyses showed that gonadotropin-releasing hormone and pancreastatin treatment led to significant increases in CgB and follicle-stimulating hormone mRNAs in gonadotroph adenomas, whereas CgA mRNA levels did not change significantly. These results show that there is a differential distribution of pancreastatin secretion in pituitary adenomas and that the hypothalamic hormone gonadotropin-releasing hormone and the CgA-derived peptide pancreastatin can regulate CgB mRNA in gonadotroph adenomas, suggesting an autocrine effect of pancreastatin on pituitary tumor function.     

An immunohistochemical study of branchial cysts.

Twenty five specimens of branchial cyst from the same number of patients have been examined. On staining with haematoxylin and eosin a consistent finding was that the mural lymphoid follicles were always aligned with their mantle zones towards the luminal epithelium. With conventional staining lymphatic sinuses were noted in 17 of the specimens, but with immunohistochemical staining these structures were apparent in 23 cysts. Their frequent occurrence in branchial cysts supports the theory that these lesions are derived from epithelial inclusions in lymph nodes. Immunohistochemical techniques for a range of other markers, using polyclonal and monoclonal antisera, showed a distribution of lymphoid and non-lymphoid tissue elements, as seen in lymph nodes and, for example, palatine tonsils. The lining luminal epithelium also shared many features in common with the crypt epithelium of tonsils.