Paragangliomas of the craniocervical region. An immunohistochemical study on tyrosine hydroxylase

Histopathological Analysis of Tumor Microenvironment and Angiogenesis in Pheochromocytoma

Pheochromocytomas (PHEOs) are relatively rare catecholamine-producing tumors derived from adrenal medulla. Tumor microenvironment (TME) including neoangiogenesis has been explored in many human neoplasms but not necessarily in PHEOs. Therefore, in this study, we examined tumor infiltrating lymphocytes (CD4 and CD8), tumor associated macrophages (CD68 and CD163), sustentacular cells (S100p), and angiogenic markers (CD31 and areas of intratumoral hemorrhage) in 39 cases of PHEOs in the quantitative fashion. We then compared the results with pheochromocytoma of the adrenal gland scaled score (PASS), grading system for pheochromocytoma and paraganglioma (GAPP) and the status of intra-tumoral catecholamine-synthesizing enzymes (TH, DDC, and PNMT) as well as their clinicopathological factors. Intratumoral CD8 (p = 0.0256), CD31 (p = 0.0400), and PNMT (p = 0.0498) status was significantly higher in PHEOs with PASS <4 than PASS ≧4. In addition, intratumoral CD8⁺ lymphocytes were also significantly more abundant in well-than moderately differentiated PHEO according to GAPP score (p = 0.0108) and inversely correlated with tumor size (p = 0.0257). Intratumoral CD68⁺ cells were significantly higher in PHEOs with regular or normal histological patterns than those not (p = 0.0370) and inversely correlated with tumor size (p = 0.0457). The status of CD163 was significantly positively correlated with that of CD8 positive cells (p = 0.0032). The proportion of intratumoral hemorrhage areas was significantly higher in PHEOs with PASS ≧4 (p = 0.0172). DDC immunoreactivity in tumor cells was significantly positively correlated with PASS score (p = 0.0356) and TH status was significantly higher in PHEOs harboring normal histological patterns (p = 0.0236) and cellular monotony (p = 0.0219) than those not. Results of our present study did demonstrate that abundant CD8⁺ and CD68⁺ cells could represent a histologically low-scored tumor. In particular, PHEOs with increased intratumoral hemorrhage should be considered rather malignant. In addition, abnormal catecholamine-producing status of tumor cells such as deficient PNMT and TH and increased DDC could also represent more aggressive PHEOs.

Management of metastatic glomus jugulare tumors

METASTATIC GLOMUS JUGULARE TUMORS (JUGULAR PARAGANGLIOMAS) ARE VERY UNCOMMON: consequently, no single report has been able to accurately describe their biologic or clinical behavior, and there are no established guidelines on caring for patients with these tumors. Identification of metastatic paraganglioma can be difficult because these tumors are known to occur synchronously, many other tumor types appear histologically similar to paragangliomas, and histologically the metastasis may not resemble the primary tumor. Immunohistochemistry, using neuroendocrine markers, and electron microscopy are the two most useful techniques available to identify definitely paragangliomas. A few studies have shown differences in the immunohistochemical staining patterns between benign and metastatic paragangliomas. We reviewed the literature and include two additional cases of metastatic glomus jugulare tumors in this article. We discuss the clinical management of these patients, the importance and usefulness of immunohistochemistry in characterizing these tumors, and their clinical outcomes.

Biochemically silent abdominal paragangliomas in patients with mutations in the succinate dehydrogenase subunit B gene

CONTEXT

Patients with adrenal and extra-adrenal abdominal paraganglioma (PGL) almost invariably have increased plasma and urine concentrations of metanephrines, the O-methylated metabolites of catecholamines. We report four cases of biochemically silent abdominal PGL, in which metanephrines were normal despite extensive disease.

OBJECTIVE

Our objective was to identify the mechanism underlying the lack of catecholamine hypersecretion and metabolism to metanephrines in biochemically silent PGL.

DESIGN

This is a descriptive study.

SETTING

The study was performed at a referral center.

PATIENTS

One index case and three additional patients with large abdominal PGL and metastases but with the lack of evidence of catecholamine production, six patients with metastatic catecholamine-producing PGL and a mutation of the succinate dehydrogenase subunit B (SDHB) gene, and 136 random patients with catecholamine-producing PGL were included in the study.

MAIN OUTCOME MEASURES

Plasma, urine, and tumor tissue concentrations of catecholamines and metabolites were calculated with electron microscopy and tyrosine hydroxylase immunohistochemistry.

RESULTS

All four patients with biochemically silent PGL had an underlying SDHB mutation. In the index case, the tumor tissue concentration of catecholamines (1.8 nmol/g) was less than 0.01% that of the median (20,410 nmol/g) for the 136 patients with catecholamine-producing tumors. Electron microscopy showed the presence of normal secretory granules in all four biochemically silent PGLs. Tyrosine hydroxylase immunoreactivity was negligible in the four biochemically silent PGLs but abundant in catecholamine-producing PGLs.

CONCLUSIONS

Patients with SDHB mutations may present with biochemically silent abdominal PGLs due to defective catecholamine synthesis resulting from the absence of tyrosine hydroxylase. Screening for tumors in patients with SDHB mutations should not be limited to biochemical tests of catecholamine excess.

Catecholamine synthesizing enzymes in 70 cases of functioning and non-functioning phaeochromocytoma and extra-adrenal paraganglioma

Immunohistochemical localization of the catecholamine synthesizing enzymes, tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC), dopamine-beta-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT), was investigated in 70 cases of functioning and non-functioning phaeochromocytomas comprising 52 of adrenal and 18 of extra-adrenal origin. Of 59 functioning tumours, 30 were mixed epinephrine and norepinephrine-producing (mixed type) and 29 were norepinephrine-producing tumours. TH, AADC and DBH were detected in all functioning phaeochromocytomas, but PNMT was limited to the mixed-type phaeochromocytomas. Non-functioning phaeochromocytomas were divided into two groups, comprising a complete type, which induced neither elevated plasma catecholamines nor their metabolites in urine, and an incomplete type which exhibited no elevated plasma catecholamines, but showed a slightly high urinary vanillylmandelic acid level. In the non-functioning complete-type tumours, immunoreactive TH was negative, but the incomplete tumours of the adrenal medulla had all four enzymes, and corresponded to a mixed-type phaeochromocytoma. AADC and DBH were present universally in all functioning and non-functioning tumours, including TH-negative tumours. TH is a rate-limiting enzyme of catecholamine biosynthesis and deficiency of TH is an important feature of extra-adrenal non-functioning phaeochromocytomas.

Glomus tumors of the temporal bone: electron microscopic and immunohistochemical evaluation

Glomus tumors arising in the temporal bone are now recognized as being part of the diffuse neuroendocrine system. Material from 12 glomus tumors was studied by means of electron microscopic and immunohistochemical techniques to determine whether there was an association between tumor size, patient age, and the neuroendocrine functions of these tumors. Electronmicroscopic evaluation (seven tumors) revealed a highly variable concentration of neurosecretory granules. Immunohistochemical staining (nine tumors) demonstrated that glomus tumors do arise from neural ectoderm and that they all contain serotonin. The concentration of serotonin seems to correlate with the concentration of neurosecretory granules seen on electronmicroscopy. In addition, higher levels of serotonin were found in two patients who were in their late sixties. It is possible that some of the neuroendocrine activity associated with glomus tumors could be the result of the release of serotonin.

Melanotic paraganglioma of the orbit: a case report

A paraganglioma of the orbit in a 21-year-old woman is presented, containing oculo-cutaneous melanin in many tumor cells, occasionally adjacent to neurosecretory granules, and in macrophages. This tumor expands the list of neuroectodermal tumors with potential melaninization.

Immunocytochemical demonstration of IGF-II-like immunoreactivity in human paraganglioma of the craniocervical region

Insulin-like-growth factor (IGF)-II-like immunoreactivity was examined in two carotid bodies and six extra-adrenal paragangliomas with use of monoclonal antibody against rat IGF-II, which crossreacts with human IGF-II. Chief cells but not sustentacular cells of the carotid body were positive at about 10% in one case and less than 1% in another case. Among four carotid body tumours, a possible vagal body tumour and one glomus jugulare tumour, all but the glomus jugulare tumour exhibited positive tumour cells irrespective of histological variations. The frequency of positive cells ranged from 20 to 60%. IGF-II like immunoreactivity, therefore, might be widely distributed in human extra-adrenal paraganglionic tissues and tumours, although its biological role in these cells remains to be elucidated.

Neuroendocrine markers in central nervous system neuronal tumors (gangliocytoma and ganglioglioma)

We studied five cases of central nervous system neuronal tumor, one gangliocytoma and four gangliogliomas, both ultrastructurally and immunohistochemically, using antibodies to neuroendocrine markers including tyrosine hydroxylase (TH), serotonin (5HT), somatostatin (SOM), met-enkephalin (MEK), leu-enkephalin (LEK), substance P (SP), gastrin, vasopressin, oxytocin, vasoactive intestinal polypeptide, adrenocorticotropic hormone and calcitonin. In all cases, the presence of dense-core vesicles (60-250 nm) in the neuronal elements was the characteristic ultrastructural finding. Synapses were observed in two cases. Immunohistochemically, variable numbers of neuronal cells showed positive staining for SOM in five cases, TH, MEK and LEK in three cases, and 5HT and SP in one case each. The others were negative. Positive immunoreactivity for multiple markers was shown in all cases. SOM, TH, 5HT and SP were present in the small- to medium-sized cells, while MEK and LEK were almost exclusively confined to the large cells. Our study clearly indicated that these tumors contained neuronal cells which were not homogeneous with regard to neuroendocrine markers.

Esthesioneuroblastoma: a nasal catecholamine-producing tumor of neural crest origin. Demonstration of tyrosine hydroxylase-immunoreactive tumor cells

An esthesioneuroblastoma in a 16-year-old male was studied ultrastructurally and immunohistochemically, using antiserum against tyrosine hydroxylase (TH), a rate-limiting enzyme in the catecholamine-synthesizing pathway. Tumor cells were fairly uniform in appearance, showing scanty eosinophilic cytoplasm and round to oval hyperchromatic nuclei, and were arranged in nests and cords of various sizes. Ultrastructurally, individual tumor cells had well-developed cell organelles including polyribosomes, microtubules, intermediate filaments, centrioles, Golgi apparatus and mitochondria. Secretory-like granules were occasionally found, predominantly in the cell processes. Immunohistochemically, many tumor cells were shown to be immunoreactive for TH. This finding strongly suggested that the present tumor was capable of producing catecholamines and that it might be derived from certain sympathetic neuronal cell nests in the superior nasal cavity.

Esthesioneuroepithelioma: a tumor of true olfactory epithelium origin. An ultrastructural and immunohistochemical study

A case of esthesioneuroepithelioma was investigated ultrastructurally and immunohistochemically, using antibodies against neurofilament protein (NFP), glial fibrillary acidic protein (GFAP), keratin, neuron-specific enolase (NSE), S-100 protein (S-100), and tyrosine hydroxylase (TH). The tumor initially manifested as an epidural mass in the anterior cranial fossa in a 64-year-old man, and about 3 1/2 years later, autopsy further revealed extensive metastases to the lymph nodes of the neck and thoracic cavity. In the cranial and nasal cavities, the tumor was composed of fairly uniform, ill-defined cells arranged in nests which were surrounded by a fibrovascular stroma. These histological features were reproduced in the metastatic tumor nodules with frequent occurrence of tubular arrangements of the tumor cells. Ultrastructurally, two different cell types were well recognized by their characteristic morphological features, which were reminiscent of sensory neurons and sustentacular cells of the olfactory epithelium. No dense-cored secretory granules were observed in the tumor cells. Immunohistochemically, the tumor showed a variable number of cells positive for NFP, keratin, NSE and S-100. NFP was present in a relatively small number of cells, which were found diffusely in the nests. Keratin was observed in the cells mainly located at the periphery. NSE-positive cells tended to form irregular clusters in the center. A few S-100-positive cells were found, without any particular arrangement.(ABSTRACT TRUNCATED AT 250 WORDS)