Gangliocytic Paraganglioma of the Duodenum: Case Report

A case of gangliocytic paraganglioma of the second portion of the duodenal loop is presented. The tumor was polypoid and, histologically, composed of mature ganglion cells, spindle cells and epithelial-like cells. Immunocytochemical examination demonstrated the presence of neurofilament 200 K and S-100 protein only in the first two types of cells; all the cells were positive for neuron-specific enolase. The reaction for cytokeratin was negative in all neoplastic components. According to morphologic and immunocytochemical findings, we suggest a hamartomatous nature of this entity.

Gangliocytic Paraganglioma of the Duodenum: Case Report

A case of gangliocytic paraganglioma of the duodenum, the 25th in world medical literature, is reported. The histologic appearance consists of epithelioid cell nests resembling « Zellballen » of carotid body tumors, together with gangliocyte-like elements. Ultramicroscopically, the cytoplasm of the cells contains round electron-dense granules or a large number of filaments. Occasional cells contain both granules and filaments.

Primary Pulmonary Paraganglioma: Report of a Functioning Case With Immunohistochemical and Ultrastructural Study

We describe a case of primary pulmonary paraganglioma, a tumor that has not been reported in sufficient detail in previous literature. The patient was a 55-year-old woman with hypertension accompanied by an elevated serum norepinephrine level (2651 pg/mL; normal 100-450 pg/mL). Computed tomography revealed a well-circumscribed solid mass, 3.5 cm in diameter, located in the lower lobe of the left lung. In the lobectomy specimen, the tumor had invaded the B8 bronchus and hilar lymph nodes with microscopic metastasis to the mediastinal nodes. The tumor showed histologic, immunohistochemical, and ultrastructural features of paraganglioma: argyrophilic cells arranged in a nesting (Zellballen) or anastomosing trabecular pattern within an arcuate vascular network. Neoplastic chief cells positive for neuroendocrine markers (CD56, synaptophysin, chromogranin A) were surrounded by sustentacular cells positive for S-100 protein. Neurofilament protein was positively stained, but cytokeratins were totally negative. On electron microscopy, chief cells possessed abundant dense core granules with an eccentric halo ("norepinephrine-type" granules). The patient's blood pressure began to decline soon after the resection, and her serum norepinephrine promptly returned to almost normal. On the basis of our experience, our case is a bona fide primary pulmonary paraganglioma, a tumor heretofore subject to considerable skepticism.

Gangliocytic paraganglioma of the bronchus: a case report with follow-up and ultrastructural assessment

We report a case of gangliocytic paraganglioma of bronchus. A 54-year-old woman underwent bronchoscopy following two episodes of right lower lobe pneumonia over the previous 5 months with unresolved chest radiographic changes. A computerized tomographic scan showed a right lower lobe endobronchial lesion, and at bronchoscopy there was a mass partly occluding the lumen of the bronchus. The biopsy and subsequent bronchoscopic resection showed a tumor with morphologic, immunohistochemical, and ultrastructural features of paragangliomatous, gangliocytic, and Schwann cell differentiation consistent with a gangliocytic paraganglioma. The lesion was treated conservatively with bronchoscopic resection and laser therapy. Histopathologic examination of recurrent tumor at 6 months showed features consistent with paraganglioma. Ten months after initial diagnosis, there was no bronchoscopic evidence of residual tumor. The occurrence of gangliocytic paraganglioma in diverse sites gives cause for the reappraisal of the histogenesis of this fascinating lesion. The variable morphology of this lesion may be an expression of the potential for divergent differentiation of a pluripotent stem cell.

Pigmented vagal paraganglioma

Paragangliomas are uncommon and those arising from the vagal trunk are rarer. Pigmented extra-adrenal paragangliomas are still rarer and reported sites of occurrence are the uterus, spine, retroperitoneum, bladder, mediastinum and orbit. The presence of abundant pigment in a cervical paraganglion has not been reported previously. We report one such unusual case of pigmented vagal paraganglioma that arose from the vagal trunk below the nodose ganglion, had massive central necrosis and showed hypovascularity on angiography. The unusual features and difficulties in the diagnosis of such cases are discussed.

Spindle cell carcinoids of the lung with paraganglioid features: a reappraisal of their histogenetic origin from paraganglia using immunohistochemical and electronmicroscopic techniques

Five cases of spindle cell carcinoids of the lung were analyzed by immunohistochemical and ultrastructural technique. They were found to be biphasic tumors composed of the major component of neuroendocrine cells (chief cells) and a minor component of dendritic cells (supporting cells). The chief cells displayed positivity for neuroendocrine phenotypic antigenic markers: neuron specific enolase (NSE), chromogranin A, and synaptophysin. They contained varying numbers of dense-core granules by electron microscopy. In addition, the chief cells expressed cytoplasmic positivity for cytokeratins. The supporting cells were dendritic in appearance and displayed strong positivity for S-100 protein in all cases. Glial fibrillary acidic protein was positive in two cases. On electron microscopy, the supporting cells were agranular and found along the external lamina surrounding the nests of tumor cells. In two cases, rare ganglion cell-like cells were present. The histomorphologic, immunohistochemical, and ultrastructural features were contrastingly different from the classical pulmonary carcinoid and rather resembled gangliocytic paragangliomas arising from small intestine and spine. It is proposed that pulmonary carcinoids with biphasic features are better designated as gangliocytic paragangliomas of the lung rather than paraganglioid carcinoids.

Duodenal periampullary gangliocytic paraganglioma: report of two cases with immunohistochemical and ultrastructural study

We report two cases of Gangliocytic Paraganglioma (GP) of the ampulla of Vater occurring in a 63-year-old and a 34-year-old individual. The patients were both admitted for a long history of intermittent gastrointestinal bleeding and abdominal discomfort, with no other symptoms. At endoscopy, the GP appeared as a polypoid, ulcerated mass in the ampullar region, measuring 2.5x1.8 and 2 cm, respectively. Microscopically, the tumors showed similar features and were composed of epithelial cells (more than 50%), spindle cells, and ganglion-like cells. The epithelial cells showed clear cytoplasm and formed nests (zellballen or paraganglioma-like groups), and less frequently, cords (carcinoid-like), extending to mucosa and submucosa. Ganglion cells were sparse, constantly associated with the spindle cells. Both epithelial and ganglion cells were synaptophysin, chromogranin A, and anti-neurofilament immunoreactive. The spindle cells were all S-100 positive. Ultrastructural studies revealed dark and light cells, rare elongated cellular processes, secretory granules, and fine fibrils resembling neurofilaments. The histogenesis of GP is still a matter of debate, however its neoplastic nature is supported by the occasionally reported malignant evolution.

Multiple endocrine neoplasia in a dog

Multiple endocrine neoplasms, including an insulinoma, bilateral adrenocortical adenocarcinomas and an aortic paraganglioma, were diagnosed after euthanasia in a 12-year-old spayed female dog of mixed breed with a history of progressive anorexia, vomiting, diarrhoea, weight loss, polyuria and polydipsia, regenerative anaemia and hypoglycaemia. The clinical, gross pathological, microscopical, immunohistochemical and ultrastructural findings were consistent with the human syndrome of multiple endocrine neoplasia.

Cytokeratins expression in paragangliomas of the cauda equina

BACKGROUND

Paragangliomas rarely involve the cauda equina region. In this location, these tumors can show misleading morphological features such as trabecular or papillary growth patterns and variable expression of cytokeratins.

METHODS

We comparatively studied the immunohistochemical and ultrastructural patterns of 3 paragangliomas of the cauda equina (PCE) and of 8 paragangliomas from other sites.

RESULTS

All the paragangliomas expressed neuroendocrine markers (neuron-specific enolase, chromogranin A, synaptophysin and neurofilament protein). In PCE, chief cells exhibited a strong positivity with a broad spectrum anti-cytokeratin antibody. The staining was diffuse in the cytoplasm or had a paranuclear dot-like disposition. In other sites, only one paraganglioma showed a focal expression of cytokeratins. At ultrastructural level, chief cells of PCE contained characteristic dense core granules and intermediate-sized filaments sometimes grouped in paranuclear whorls.

CONCLUSION

The dual immunophenotype of PCE, paraganglionic and epithelial, must be recognized in order to distinguish these tumors from, for example, a metastasis of a neuroendocrine carcinoma. PCE are slow-growing tumors and have mostly a favorable prognosis after complete surgical excision.

Case of the month: January 1998--43 year old male with radicular pain

A 43-year-old male presented with progressively worsening right lower extremity pain. MRI of the spine showed a discrete intradural, extramedullary, homogeneously enhancing, sausage-shaped mass at L1-L2, noted intraoperatively to expand the filum terminale. Gross, histological, and electron microscopic findings were those of a paraganglioma. The case is used to discuss the differential diagnosis for sausage-shaped tumors of the filum terminale.

Gangliocytic paraganglioma of the duodenum: report of a case with immunocytochemical and ultrastructural investigation

A case of gangliocytic paraganglioma is reported in a 70-year-old female presenting as a polypoid tumor of the second portion of the duodenum. Immunohistochemical and ultrastructural features of the tumor indicate that gangliocytic paraganglioma of the duodenum (GPD) represents an unique tumor originating from the neuroectodermal derivative exhibiting dual phenotypic expression toward paraganglionic and epithelial (neuroendocrine) cells. These findings correlate well with the literature and it is further suggested that GPD belongs to the histopathologic spectrum of tumors derived from the neural crest. The findings offer a plausible explanation for histogenetic possibilities of the occurrence of pure epithelial tumors (i.e., carcinoid-like tumors) in the paraganglionic systems. The patient remains with no evidence of disease 4 years following a simple polypectomy.

[Paraganglioma of the larynx]

A rare case of a large paraganglioma of larynx was presented. The whole tumor was removed by partial laryngectomy.

Olfactory neuroblastoma. An immunohistochemical, ultrastructural, and flow cytometric study

BACKGROUND

Olfactory neuroblastoma is an uncommon neuroectodermal tumor of the upper nasal cavity, microscopic features of which are not always homogeneous. No morphologic features have been found to correlate reliably with prognosis.

METHODS

Twenty-six olfactory neuroblastomas occurring in 14 females and 12 males, ages 18-78 years, were studied by immunohistochemistry, electron microscopy, and DNA flow cytometry. Survival rates were statistically analyzed relative to several variables.

RESULTS

Microscopically, 22 tumors formed a morphologic spectrum intermediate between paraganglioma (PG) and neuroblastoma (NB). Others included two ganglioneuroblastomas (GNB), one lesion exhibited biphasic (neuronal and epithelial) differentiation, and one tumor showed predominantly epithelial features. Immunoreactivity for neuronal and neuroendocrine markers included synaptophysin in 77%, neurofilament protein in 38%, class III beta-tubulin in 81%, and chromogranin A in 77%. In 88% of cases, elongated S-100 protein-positive cells surrounded tumor lobules. Cytokeratin and epithelial membrane antigen immunoreactivity were noted in six (23%) and two (8%) tumors, respectively. Aberrant p53 expression was detected in 16 tumors (62%). The Ki-67 labeling index (LI) varied from 0%-43.8% (mean, 7.4%). Ultrastructurally, 80-230 nm dense core granules were noted within perikarya and as in microtubule-containing processes in all of the 11 tumors studied by electromicroscopy. Lobules of seven tumors were surrounded by electron-dense sustentacular cells. Epithelial tumors exhibited obviously epithelial features in addition to neuronal differentiation. DNA flow cytometry demonstrated a high incidence of polyploidy and aneuploidy (78%) and a wide range of percent S phase fractions (1.5%-21.8%; mean, 9.0%). The study showed that longer survival rates are related significantly to (1) the occurrence of metastases which was linked to tumor subtype, (2) to a higher incidence of S-100 protein-positive cells, and (3) to a low (< 10%) Ki-67 labeling index.

CONCLUSIONS

The present study indicates that (1) although typical olfactory neuroblastomas exhibit PG/NB differentiation, they more closely resemble PG, (2) occasional tumors show GNB and/or epithelial differentiation, and (3) survival rates may correlate with S-100 protein immunoreactivity and Ki-67 LI. Cancer 1995; 76:4-19.

Neuroendocrine neoplasms of the larynx. Importance of the correct diagnosis and differences between atypical carcinoid tumors and small-cell neuroendocrine carcinoma

Findings in the present study have confirmed that the diagnosis of neuroendocrine tumors of the larynx (NETL) requires that a panel of neuroendocrine markers and electron microscopy be performed. This means that the clinician must be aware of the clinical presentations of such patients and should send fresh biopsy specimens to the clinical laboratory for optimal tissue studies. As shown in this study, the possibility of misdiagnosis of an atypical carcinoid tumor (ACT) is rather high. In establishing a diagnosis, a part of the material should be fixed for conventional histology, a part for immunohistochemistry and a part for electron microscopy. The correct diagnosis of NETL is obviously of great importance for subsequent treatment and prognosis. Patients with the diagnosis of ACT of the larynx require surgical treatment. Our findings also show that small-cell neuroendocrine carcinomas of the larynx should be considered to be a disseminated disease at initial presentation. A metastatic workup is necessary, but radical surgical procedures should be avoided. The combination of radiotherapy and chemotherapy is always indicated.

Giant mitochondria with paracrystalline inclusions in paraganglioma of the urinary bladder: correlation with mitochondrial abnormalities in paragangliomas of other sites

Mitochondrial abnormalities have received relatively little attention in the ultrastructural evaluation of paragangliomas. Review of the few literature references dealing with this issue, however, reveals that quantitative and qualitative changes of these organelles occur in that context. A bladder paraganglioma is described that was characterized by numerous mitochondria, which in addition displayed giant forms along with matrical paracrystalline inclusions. Upon retrospective review of 12 archival cases of paragangliomas, enlarged and structurally abnormal mitochondria were found in all of them. Although various speculations can be made, the mechanism of formation and the pathophysiologic significance of these abnormal mitochondria remain unknown. From a morphologic diagnostic point of view, however, these abnormalities, which in this case of bladder paraganglioma were also light microscopically evident, can be of significant help in establishing the correct diagnosis.

[Flow-cytometric study of familial paragangliomas of the carotid body]

Paragangliomas of the carotid body with an autosomal dominant genetic transmission have been described in a familial presentation in 7-10% of all the cases observed. In less than 10% malignancy is confirmed by secondary metastatic localization rather than by typical histological features of malignant diseases, such as vascular or perineural invasion, nuclear pleomorphism, mitotic activity. The purpose of the study is to present a familial group of paragangliomas of the carotid boy and a flow cytometric analysis of tumor content DNA and to discuss the prognostic value of the results. The paragangliomas of these related patients (father and daughter) are diploid, without regional lymph node or distant metastases; clinical and cytometric findings support a good prognosis even if an accurate follow up of such neuroendocrine tumors is nonetheless mandatory. Considering data in Literature, the Authors also propose a prognostic classification of paragangliomas as follows: noninvasive (capsulated, without vascular or perineural infiltration, diploid); locally invasive (histological signs such as vascular or perineural infiltration, nuclear pleomorphism, abnormal mitoses etc, diploid); potentially malignant (histological signs, non-diploid, expression of few antigens) and malignant (regional or distant metastases).

Malignant retroperitoneal paraganglioma with intranuclear vacuoles in a fine needle aspirate. A case report

The cytologic findings in fine needle aspiration smears and cell blocks from a malignant retroperitoneal paraganglioma with subsequent histologic confirmation are described. The aspirate contained clusters of cells with ill-defined borders, often varied in size, round or oval nuclei and marked anisokaryosis. An unusual feature was the presence of prominent intranuclear vacuoles in some cells. The histologic and ultrastructural findings, as well as the results of histochemical and immunodiagnostic staining, are also presented.

Validation of somatostatin receptor scintigraphy in the localization of neuroendocrine tumors

Somatostatin analogs are used in the control of hormonal hypersecretion and tumor growth of patients with acromegaly, islet cell carcinomas and carcinoids. Recently we showed that somatostatin receptor positive tumors can be visualized in vivo after the administration of radionuclide-labeled somatostatin analogs. Receptor imaging was positive in 18/21 islet cell tumors, 32/37 carcinoids, 26/28 paragangliomas, 9/14 medullary thyroid carcinomas, and 5/7 small cell lung cancers. Somatostatin receptor imaging is an easy, harmless and painless diagnostic method. It localizes multiple and/or metastatic tumors, predicts the successful control of hormonal hypersecretion by octreotide and seems to be of prognostic value in certain types of cancer. This scintigraphic method might help in patient selection for clinical trials with somatostatin analogs in the treatment of neuroendocrine cancers.

Malignant paraganglioma of the uterus

We report a malignant uterine paraganglioma in a 40-year-old female, who died 7 months after the initial diagnosis. On light microscopy the tumour showed a typical zellballen pattern as well as a pronounced cellular pleomorphism. In many tumour cells hyaline globules were demonstrated within the cytoplasm. Immunohistochemically the lesion was characterized by the presence of neuron-specific enolase, protein gene product 9.5 and synaptophysin, and electron microscopically by the occurrence of neurosecretory granules.

A clinico-pathological classification of laryngeal paraganglioma

A case of metastatic laryngeal paraganglioma is presented. We have reviewed the current world literature on this entity and thereby identified two apparently distinct types of this rare lesion (type I and type II). The histopathological features are unhelpful in discriminating these two types and this is instead based on clinico-epidemiological differences. The latter are annotated and discussed with respect to prognosis and management. A true estimate of the frequence of type II (potentially malignant) awaits the utilization of the recent improvements in diagnostic techniques.

Cauda equina tumor with ependymal and paraganglionic differentiation

We describe the case of a 31-year-old woman who was first treated for a pigmented choroid plexus papilloma of the fourth ventricle. Ten year later, she developed a new tumor in the region of the cauda equina. This second neoplasm contained areas of papillary ependymoma that displayed phosphotungstic acid hematoxylin-positive glial fibers and immunoreactivity for glial fibrillary acidic and S-100 proteins. Areas of ependymoma merged with others that displayed the appearance of a paraganglioma, including lobules and nests of chief cells immunoreactive for neuron-specific enolase, synaptophysin, chromogranin, and serotonin. Satellite cells, but not chief cells, stained for glial fibrillary acidic and S-100 proteins. Electron microscopy showed features of both ependymal and paraganglionic differentiation, including intercellular lumina with microvilli, junctional complexes, cell processes with closely packed filaments, and dense core granules. Our case represents a rare example of a cauda equina neoplasm with simultaneous ependymal and paraganglionic differentiation. To our knowledge, this is the first described example of a tumor of this region showing features of both ependymoma and paraganglioma.

The intriguing nature of gastric tumors in Carney's triad. Ultrastructural and immunohistochemical observations

The authors describe clinical and pathologic features present in an adolescent girl who had a gastric tumor and mediastinal mass. The latter was shown to be a paraganglioma, and the gastric neoplasm was classified as malignant "leiomyoblastoma," with the use of current histologic criteria. This tumor had metastasized to the liver but not to the lungs. Although the histologic criteria for leiomyoblastoma were fulfilled, no definite evidence of smooth-muscle cell differentiation was present ultrastructurally or by immunostaining methods. Gastric tumors that form part of "Carney's triad" are known to differ clinically and pathologically in important ways from smooth-muscle cell malignant neoplasms that are not part of this syndrome. Some have been classified as gastrointestinal autonomic nerve tumors, but the current study did not confirm this contention. The nature of gastric leiomyoblastomas in Carney's multitumoral association remains undecided.

Paraganglioma of the urinary bladder: immunohistochemical, ultrastructural, and DNA flow cytometric studies

Primary paraganglioma arises infrequently in the urinary bladder. We present the clinicopathologic, immunohistochemical, ultrastructural, and DNA flow cytometric findings in three cases (one man and two women). Ages at diagnosis were 19, 35, and 45 years. One female presented with paroxysmal headaches and hypertension that followed urination; the remaining two patients presented with hematuria. Immunohistochemical studies revealed positive reactivity for chromogranin (three patients), met-enkephalin (three), leu-enkephalin (three), vasoactive intestinal polypeptide (two), serotonin (one), and S-100 protein (one; sustentacular cells only). Neurosecretory granules were identified in all cases; in the patient with hypertension, the granules were small with eccentric cores similar to those of adrenal pheochromocytomas. A nondiploid DNA flow cytometric pattern was present in all three patients, an aneuploid pattern was present in two, and a tetraploid pattern was present in one. After diagnosis, one patient was alive without progression at 7 years, one died of an uncertain cause at 5 years, and one suffered multiple recurrences over a 24-year period before developing metastatic disease. While the presence of aneuploidy has been shown to be a predictor of malignant behavior in adrenal pheochromocytomas, our study illustrates that DNA ploidy cannot be used as a diagnostic criterion for malignancy in urinary bladder paraganglioma.

Neuroendocrine tumors of the larynx

A review of the international literature has revealed 68 paragangliomas, 42 large cell, and 74 small cell tumors of the larynx. Paragangliomas are usually benign, although malignant cases have been reported. Large cell tumors are malignancies associated with a high incidence of early cervical metastasis. Small cell tumors are aggressive cancers characterized by early, diffuse metastatic disease. All three neoplasms demonstrate a propensity for the supraglottic larynx. While surgery remains the treatment of choice for paragangliomas and large cell cancers, small cell cancers are best treated by radiotherapy and chemotherapy. The determinate 5-year survival for patients with paragangliomas, large cell, and small cell cancers is 60%, 34%, and 14%, respectively. While representing distinct clinical entities, these neoplasms demonstrate similar ultrastructural and histochemical features and should be classified as neuroendocrine tumors of the larynx (NETL). A comprehensive analysis of these laryngeal tumors is presented herein. Their clinical behavior and management options are reviewed and a scheme for their nomenclature and classification is proposed.

Paraganglioma of the cauda equina. A case report and review of the literature

A case of paraganglioma of the cauda equina is reported. The patient was a 55-year-old Japanese woman who complained of lower back pain and gradual weakening of the left lower extremity, she was diagnosed as having a spinal cord tumor, and the tumor was removed surgically. Histologically, the tumor was encapsulated, and consisted of solid nests of large, polyhedral epithelioid cells with abundant eosinophilic cytoplasm. The nests were separated from each other by a thin fibrovascular stroma. Grimelius staining revealed neurosecretory granules in the cytoplasm of the tumor cells. This was further confirmed by electron microscopic observation. The tumor cells were immunohistochemically positive for neuron-specific enolase (NSE), but negative for glial fibrillary acidic protein (GFAP). On the basis of the histologic, immunohistochemical and electron microscopic features of the tumor cells, the tumor was diagnosed as paraganglioma. The cauda equina is a rare location for this type of tumor, and only a limited number of cases have been reported.

Crystalloid structures in retroperitoneal paragangliomas: a light and electron microscopic study

Samples from three clinically functional retroperitoneal paragangliomas were studied by light and electron microscopy. The tumors exhibited a Zellballen pattern histologically, and ultrastructurally all three neoplasms consisted of cells containing catecholamine granules. Prominent cytoplasmic crystalloids were present in all cases. The crystalloids were identified in routine histologic sections, demonstrated eosinophilia, and stained with periodic acid-Schiff, Giemsa, phloxine-tartrazine, and azan stains. Ultrastructurally the crystalloids were osmiophilic, often appeared as slender needles, were membrane bound, and demonstrated a periodicity of 9 nm. The crystalloids, unlike the catecholamine granules, were negative for catecholamine fluorescence. X-ray microanalysis, however, revealed the selective presence of chromium in both catecholamine granules and crystalloids.

Giant gangliocytic paraganglioma of the filum terminale. Case report

The clinical and pathological features of a giant cauda equina paraganglioma arising from the intradural filum terminale is described. Scattered mature large neurons characterized the tumor as a gangliocytic paraganglioma. Histologically, these neoplasms have considerable similarity with ependymoma and the diagnosis can be easily missed unless special techniques are employed.

Paraganglioma of the spermatic cord. Report of a case with immunohistochemical and ultrastructural studies

We describe a case of paraganglioma arising in the spermatic cord, which is an extremely rare location. Immunohistochemical studies characterized two types of cells: (1) polygonal cells expressing neuron-specific enolase, chromogranin A, and synaptophysin and (2) S100 protein-positive sustentacular cells. Electron microscopy revealed that within the cytoplasm of the polygonal cells, there were electron-dense granules whose morphological appearance was consistent with that of neurosecretory granules. Paraganglioma of the spermatic cord may originate from embryonic chromaffin cells that have followed the testis into the scrotum.

Gastric paraganglioma: an immunohistological and ultrastructural case study

This is a report of the immunohistochemical and ultrastructural features of a case of paraganglioma of the stomach in a 61-year-old woman who presented with melaena. The typical 'Zellballen' arrangement of epithelial cells with granular cytoplasm was present and the tumour was highly vascular. The polygonal epithelial cells stained strongly for neuron specific enolase and the intervening elongated sustentacular or support cells were positive for S100 protein and vimentin. Many dense core granules were present within the epithelial cells while the elongated support cells contained plentiful diffuse intermediate filaments. No hybrid cells or ganglion cells were present in the tumour. This is the sixth recorded case of gastric paraganglioma and the first to be studied in detail by immunostaining and electron microscopy.

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.

A review of the histology, ultrastructure, immunohistology, and molecular biology of extra-adrenal paragangliomas

This review summarizes our understanding of extra-adrenal paragangliomas, a subject that has evolved considerably during the past several years. Our object was to review the anatomical, histologic, and biological features of normal and neoplastic glands, with emphasis on immunohistologic studies, and briefly discuss the potential application of nucleic acid hybridization. Since it is difficult to predict clinical outcome for patients with paragangliomas, we have emphasized the differences between benign and malignant paragangliomas, concentrating on recent results obtained using immunohistologic techniques. These studies have emphasized the critical importance of the identification, by immunohistologic means, of two distinct cell populations, chief cells (type I) and sustentacular cells (type II). The relationship between these two cell populations, stable in normal glands and benign tumors, is progressively lost in tumors of increasing degrees of malignancy, sustentacular cells being absent from the most progressively metastasizing paragangliomas.

[An autopsied case of malignant paraganglioma of the posterior thoracic cavity]

An autopsied case of a malignant paraganglioma of the posterior thoracic cavity is reported. A 68-year-old man had complained of chest discomfort, and serial examinations revealed a functioning paraganglioma with bone metastasis. After death a pathological examination revealed that the tumors consisted of alveolarly arranged cells and well developed capillary vessels. Numerous neurosecretory granules were observed on viewing by electron microscopy. An immunohistochemical examination showed that most of the tumor cells were positive for NSE, while only a few cells were positive for the S-100 protein. These results indicate that a paraganglioma originating from the aortic sympathetic paraganglia had similar features of a carcinoid and a neuroblastoma.

Malignant primary pulmonary paraganglioma

The histological, immunocytochemical, and electron microscopic findings in a case of malignant primary pulmonary paraganglioma are reported. The existence of this rare tumour is evidence for the presence of pulmonary chemoreceptors.

Paragangliomas: assessment of prognosis by histologic, immunohistochemical, and ultrastructural techniques

To predict clinical outcome, we studied 42 paragangliomas from 37 patients by routine histology, immunohistochemistry, and electron microscopy. A panel of antisera to neuron-specific enolase (NSE), chromogranin, and met-enkephalin was used to identify chief (type I) cells, and S-100 protein and glial fibrillary acid protein (GFAP) sustentacular (type II) cells. The intensity of staining of type I cells and the density of type II cells were assessed semiquantitatively (0 to 4+) in a total of 38 tumors. A total of 23 of 24 low-grade tumors (solitary, multiple, or associated with other neoplasms; 95.8%) contained type II cells immunoreactive with either S-100 protein or GFAP, and all were positive when S-100 protein and GFAP were used in combination. Five of the nine intermediate-grade (recurrent and/or locally aggressive) tumors were identified as glomus jugulare tumors (GJT). Three intermediate-grade GJTs were devoid of GFAP-reactive type II cells and four GJTs were negative for S-100 protein. Type II cells were identified in only one of five high-grade (malignant) paragangliomas and that tumor contained vanishingly rare cells that were weakly S-100 protein positive but GFAP negative. Sustentacular cell density and chief cell staining intensity were both inversely related to tumor grade. The most sensitive chief cell marker was NSE (92.1%), followed by chromogranin (84.2%). The least sensitive (73.0%) and specific marker was met-enkephalin. Combinations of NSE or chromogranin with met-enkephalin identified chief cells in all cases. Electron microscopy identified neurosecretory granule-containing chief cells, but was of less value in delineating sustentacular cells because of their scarcity and the absence of specific features. By comparison, immunohistochemistry was superior in identifying sustentacular cells. The use of an immunohistochemical panel, in addition to routine histology, can confirm the diagnosis of a paraganglioma and can give an indication of the likely prognosis for a patient.

Paraganglioma of the cauda equina: an ultrastructural and immunohistochemical study of two cases

The ultrastructural and immunohistochemical features of 2 paragangliomas arising in the cauda equina are described. In both cases the tumor cells were arranged in small nests or cords and contained characteristic neurosecretory granules, lamellar stacks of rough endoplasmic reticulum (RER), and some well-developed Golgi apparatuses in their cytoplasm. The cells varied in electron density; the darker cells, occasionally resembling sustentacular cells, were probably dehydrated light cells because they contained a few neurosecretory granules. Sustentacular cells were difficult to identify by electron microscopy, but irregularly distributed S-100 protein and glial fibrillary acidic protein (GFAP) were found in these cells by immunostaining. Many tumor cells contained abundant neurofilaments. Curiously, a few cytokeratin-positive cells were found in 1 case. On microscopic examination, a small area of ganglioneuroma was found associated with the paraganglioma in 1 case. Ganglionic differentiation was concluded to be frequent in paragangliomas of the cauda equina region as in duodenal paragangliomas.

Paraganglioma of the filum terminale internum. Report of a case and review of the literature

A case of paraganglioma of the filum terminale is presented where normal sympathetic ganglion cells were seen in conjunction with tumour cells in a well-encapsulated tumour, suggesting a possible origin from heterotopic sympathetic ganglion.

Malignant paraganglioma of the thyroid gland

Paragangliomas of the thyroid gland are rare lesions, only four previous cases having been reported in the literature, to our knowledge. We report herein a fifth case, which, to our knowledge, is the first to exhibit malignant behavior manifested by invasion into perithyroidal soft tissue through the wall of the trachea into the tracheal mucosa.

Duodenal gangliocytic paraganglioma. Clinicopathologic and immunocytochemical study of 11 cases

The clinicopathologic features of 11 cases (8 in men) of duodenal gangliocytic paraganglioma are presented. The patients averaged 56 years of age; none showed evidence of phakomatosis. Ten tumors occurred in the second portion of the duodenum, and one arose in the third portion. All tumors were polypoid, and half presented with gastrointestinal bleeding. The neoplasms were composed of paraganglioma and carcinoid-like elements, neurons, and Schwann as well as sustentacular cells. All tumors behaved in a benign fashion after local resection or snare polypectomy; long-term follow-up (1-25 years; mean, 8.3 years) showed no recurrence in any case. Immunocytochemical examination demonstrated the presence of somatostatin, serotonin, and human pancreatic polypeptide within endocrine cells and neurons.

Melanotic paraganglioma of the uterus

Two cases of melanotic paraganglioma of the uterus are reported. Interpreted as a pigmented paraganglioma, both lesions were an incidental finding in uteri removed for unrelated benign conditions. Microscopically, both tumors were circumscribed, and composed of nests of large round or angulated polygonal cells with abundant clear or granular pale, eosinophilic cytoplasm. Large amounts of coarse intracytoplasmic melanin pigment were present in many cells, whereas other cells were completely devoid of pigment. Both lesions contained psammoma bodies. Electron microscopy showed abundant intracellular melanosomes, including many compound melanosomes and few premelanosomes. A lamellar whorled structure was the dominant infrastructure on which melanin pigment was deposited in many cells. The absence of microvilli or dendritic cell processes and basal lamina, as well as the lack of S-100 protein, pointed against a Schwannian or melanocytic differentiation. The presence of abundant pigment and only rare neuroendocrine-like secretory granules in the cytoplasm of a few cells indicated divergence from classic paraganglioma. Architecturally, this lesion is similar to a paraganglioma; but, functionally, instead of neuroendocrine granules, the tumor cells produce melanin pigment.

Duodenal gangliocytic paraganglioma occurring in adolescence

A 15-year-old boy complained of abdominal pain and massive upper gastrointestinal hemorrhage. Endoscopic evaluation demonstrated an ulcerated, submucosal mass involving the ampulla. This was locally excised and found to show the characteristic histologic and ultrastructural features of a gangliocytic paraganglioma. Similar lesions have been reported in 29 patients with a mean age of 55 years (range, 32-80). Twenty-six patients complained of abdominal pain or gastrointestinal bleeding, symptoms that mimic those of peptic ulcer disease. These tumors are uniformly benign, nonencapsulated, and submucosal. They usually arise in the second portion of the duodenum and are treated by simple excision. This patient is the youngest reported, and his case is presented as an illustration of an unusual tumor that can masquerade clinically and radiologically as a duodenal ulcer. The importance of endoscopic evaluation is stressed.

Crystals in a jugulotympanic paraganglioma

The morphologic features of a jugulotympanic paraganglioma are reported. The tumor showed the usual histology of paragangliomas. No sustentacular cells were identified. In the tumorous chief cells there were typical neurosecretory dense-core granules 60-180 nm in diameter. Granules averaging 400 nm in diameter were also observed, sometimes with a regular rhomboid core or crystallized content. Rhomboid crystals were seen in the cytoplasm in membrane-bound spaces and in telolysosomes. The crystals had a substructure consisting of alternating light and dark lines with a periodocity of 5-10 nm. Such crystals had not been reported previously in paragangliomas. The possible origin of the crystals is discussed.

Neuroendocrine carcinomas of the larynx. A study of two types, one of which mimics thyroid medullary carcinoma

We studied 13 neuroendocrine carcinomas of the larynx. They constituted 59% of the 22 nonepidermoid carcinomas of the larynx seen at Memorial Hospital during a 45-year period, and for which adequate material was available for review. Four tumors were histologically identical to small cell carcinomas of the lung and were classified as small cell neuroendocrine carcinomas (SCNC). One case represents one of the original descriptions of the laryngeal SCNC. No SCNC was argyrophil, and of the three studied immunohistochemically, all contained neuron-specific enolase, one carcinoembryonic antigen (CEA) and one serotonin. Nine tumors were large cell carcinomas (LCNC). Eight LCNC were argyrophil, and all nine contained neuron-specific enolase, six calcitonin, four CEA, one HCG, two serotonin, and two somatostatin. The laryngeal neuroendocrine carcinomas commonly presented in chronic cigarette smokers with mean ages of 63 (SCNC) and 60 (LCNC), were not associated with other endocrine tumors, and proved highly fatal in spite of radical surgery and radiation therapy. At last follow-up only one patient was alive (after 13 months). Patients dying with SCNC survived a mean of 11 months, and those with LCNC, 36 months. To determine whether the laryngeal LCNC most closely resembles pulmonary neuroendocrine tumors, head and neck paragangliomas, or thyroid medullary carcinoma (TMC), they were histologically, histochemically, and immunohistochemically compared with control cases of each group. Overall, LCNC most closely resembles TMC, and given the frequency with which each presents as a neck mass, misinterpretation of one for the other is very possible. Evidence is provided suggesting that some LCNC have also been mistaken for the laryngeal paraganglioma.

Neuroendocrine markers in paragangliomas of the head and neck

Eighteen paragangliomas of the head and neck (11 carotid body tumors, four glomus tympanicum tumors, three glomus jugulare tumors) were studied retrospectively. Tissue from each of these tumors was immunostained for the presence of serotonin, a variety of neuropeptide hormones, and the enzyme neuron-specific enolase (NSE). Seven tumors were studied by electron microscopy. The clinical and laboratory records were reviewed for evidence of endocrine activity or metabolic imbalance. All tumors displayed diffuse and intense immunostaining for NSE. In addition, a wide variety of hormonal substances could be identified. Those most frequently demonstrated were serotonin and leu-enkephalin. Ten of the 11 carotid body tumors demonstrated immunoreactivity for multiple hormones. By electron microscopy all tumors contained a heterogeneous population of membrane-bound neurosecretory granules. None of these tumors was associated with a clinically apparent endocrine syndrome. We conclude that paragangliomas of the head and neck are neuroendocrine tumors that are capable of synthesizing a variety of hormonal substances. These hormonal substances rarely elicit a clinically apparent endocrine or metabolic imbalance. All of the tumors demonstrated immunostaining for NSE. Future studies on serum levels of NSE may provide useful diagnostic and follow-up data.

Cardiac paragangliomas. A clinicopathologic and immunohistochemical study of four cases

Cardiac paragangliomas are extremely rare neoplasms. Four surgically resected tumors were examined by immunohistochemistry and electron microscopy. The patients ranged in age from 18 to 36 years. All patients had hypertension and elevated urine catecholamine levels. Three tumors were located on the posterior left atrium, and one tumor was located in the interventricular groove at the aortic root. The tumors ranged in size from 5 to 7 cm, and they displayed a prominent Zellballen pattern without significant necrosis or mitosis. The tumors were mostly unencapsulated and infiltrated adjacent cardiac tissue in two cases. Immunoperoxidase staining showed that all tumors were positive for chromogranin and neuron-specific enolase. Three tumors were positive for methionine enkephalin. Positive staining for S-100 protein was seen in the sustentacular cells of all tumors but was negative in chromaffin cells. All tumors were negative for insulin, glucagon, gastrin, vasoactive intestinal polypeptide, somatostatin, adrenocorticotropic hormone, calcitonin, serotonin, pancreatic polypeptide, and rat atrial peptide. Ultrastructural studies of all four tumors showed moderate numbers of predominantly norepinephrine-type granules and a few epinephrine-type granules. These results show that cardiac paragangliomas are commonly found in close proximity to the left atrium and have immunohistochemical and ultrastructural features similar to other paragangliomas.

Paraganglioma of the cauda equina: a histological, ultrastructural and immunocytochemical study of two cases with a review of the literature

The clinical and pathological features of two paragangliomas arising in the cauda equina are described and compared with 14 previous reports. The light microscopic features were similar to those of paragangliomas from other sites, with a 'Zellballen' pattern of cells containing argyrophil granules. Electron microscopy showed densely staining membrane-bound granules, cilia and fibrous bodies in the cytoplasm. The last two features only occur in paragangliomas from this site. gamma-Enolase was demonstrated by the peroxidase-antiperoxidase technique for the first time in these neoplasms. This technique was also used to demonstrate cytokeratins, which appear to be associated with the presence of fibrous bodies. The pathological findings suggest that paragangliomas in this site arise from pre-existing paraganglia, possibly of the visceral autonomic group. The prognosis in cases treated by complete excision appears to be good.