Malignant carotid body paraganglioma: light and electron microscopic study of the tumor and its metastases

A Global Bibliometric Analysis of the Top 100 Most Cited Articles on Carotid Body Tumors

The carotid body, situated at the common carotid artery bifurcation, comprises specialized glomus cells responsible for sensing blood oxygen, carbon dioxide, pH, and temperature changes, crucial for regulating breathing and maintaining oxygen homeostasis. Carotid body tumors (CBTs), arising from these cells, are rare, representing only 0.5% of head and neck tumors, often presenting as benign, slow-growing, vascularized masses. In February 2023, this bibliometric analysis was conducted, which involved screening 1733 articles from the Web of Science database. The screening process was based on citation count, and articles were selected for inclusion based on specific criteria that focused on CBTs located within the carotid bifurcation. Rigorous selection involved independent screening and data extraction by four authors. The top 100 articles, published between 1948 and 2019, totaled 6623 citations and were authored by 98 unique first authors from 22 countries and 77 institutions, spanning 42 journals. Treatment articles were the predominant category, comprising 49% of the literature. This analysis offers insights into publication trends, identifies literature gaps, and outlines areas of research focus, providing a valuable resource to guide future studies on CBTs.

Paragangliomas and Anemia: Literature Review and Case Report

Paragangliomas are rare neuroendocrine tumors that arise from the extra-adrenal autonomic paraganglia, i.e., small organs consisting mainly of neuroendocrine cells that are derived from the embryonic neural crest and have the ability to secrete catecholamines. Paragangliomas can derive from either parasympathetic or sympathetic paraganglia. Most of the parasympathetic ganglia-derived paragangliomas are nonfunctional, and symptoms result from mass effect. Conversely, the sympathetic paragangliomas are functional and produce catecholamine. Although such patients could have symptoms similar to pheochromocytoma, mass effect symptoms, or non-specific symptoms, being benign tumors, they can also present with anemia, specifically iron-deficiency anemia. Considering that neoplastic pathology is chronically accompanied by moderate, normochromic, normocytic anemia, association between paragangliomas that are mostly benign but with a potential degree of malignancy and anemia is not as frequent as expected, with only 12 cases reported in the literature. We report a case of a 54-year-old female patient diagnosed with a paraganglioma of the carotid glomus accompanied by severe normochromic, normocytic anemia, which reached normal limits after excision of the paraganglioma.

Potential Biomarkers of Metastasizing Paragangliomas and Pheochromocytomas

Paragangliomas and pheochromocytomas (PPGLs) are rare neuroendocrine tumors originating from paraganglionic tissue in many sites of the body. Most PPGLs are characterized by nonaggressive behavior but all of them have the potential to metastasize. PPGLs represent a great diagnostic dilemma as it is difficult to recognize tumors that are likely to be metastasizing; criteria of malignancy can be found both in benign and metastatic forms. This review aims to analyze the current knowledge of the nature of metastasizing PPGLs paying particular attention to head and neck paragangliomas (HNPGLs). Potential predictors of the malignancy risk for PPGLs were summarized and discussed. These data may also help in the development of diagnostic and prognostic strategies, as well as in the identification of novel potential therapeutic targets for patients with PPGLs.

Carotid Body Paraganglioma with Prominent Lymphocytic Infiltration Mimicking Metastatic Lymph Node: A Case Report

Carotid body paraganglioma is a neuroendocrine neoplasm of the mandibular region. Due to its prominent stromal alternations, carotid body paraganglioma is a great emulator of other neoplasms in the head and neck region especially in metastatic tumors and its definite diagnosis is a great challenge. To the best of our knowledge, the most frequently reported variant is sclerosing and paraganglioma with a prominent lymphoplasmacytic infiltration is extremely rare. We report a rare case of a carotid body lymphoplasmacytic paraganglioma presented as a single asymptomatic mass of the right mandibular region in a 45-year-old woman. In order to exclude other possibilities, the use of immunohistochemistry is essential which shows a strong positive immunoreaction for chromogranin and synaptophysin. Surgical resection is the treatment of choice which is replaced with radiotherapy in contraindications. Overall, the tumor has a favorable clinical outcome.

Carotid Body Tumor Microenvironment

Carotid body tumors (CBTs) are rare paragangliomas, comprising 0.5% of all head and neck tumors, and 65% of head and neck paragangliomas. A majority of CBTs occur sporadically, while 15% are familial or hyperplastic in the setting of chronic hypoxia. They usually present as unilateral, well-circumscribed rubbery masses, arising at the level of the carotid bifurcation. A majority of CBTs are painless and therefore may evade diagnosis for months to years. Symptomatic lesions occur due to progressive cranial nerve IX, X, or XII dysfunction, manifesting as hoarseness, dysphagia, vertigo, coughing, or odynophagia. Other local symptoms include neck discomfort, pulsatile tinnitus, hearing loss, or carotid sinus syndrome. Appropriate workup includes a thorough physical exam followed by radiographic imaging, vascular studies, and biochemical workup with 24 h urinary catecholamine or metanephrine analysis. The management of these tumors, which involves standalone surgical resection or following embolization for larger and more vascular tumors, will also be discussed.

PHD2 inactivation in Type I cells drives HIF-2α-dependent multilineage hyperplasia and the formation of paraganglioma-like carotid bodies

KEY POINTS

The carotid body is a peripheral arterial chemoreceptor that regulates ventilation in response to both acute and sustained hypoxia. Type I cells in this organ respond to low oxygen both acutely by depolarization and dense core vesicle secretion and, over the longer term, via cellular proliferation and enhanced ventilatory responses. Using lineage analysis, the present study shows that the Type I cell lineage itself proliferates and expands in response to sustained hypoxia. Inactivation of HIF-2α in Type I cells impairs the ventilatory, proliferative and cell intrinsic (dense core vesicle) responses to hypoxia. Inactivation of PHD2 in Type I cells induces multilineage hyperplasia and ultrastructural changes in dense core vesicles to form paraganglioma-like carotid bodies. These changes, similar to those observed in hypoxia, are dependent on HIF-2α. Taken together, these findings demonstrate a key role for the PHD2-HIF-2α couple in Type I cells with respect to the oxygen sensing functions of the carotid body.

ABSTRACT

The carotid body is a peripheral chemoreceptor that plays a central role in mammalian oxygen homeostasis. In response to sustained hypoxia, it manifests a rapid cellular proliferation and an associated increase in responsiveness to hypoxia. Understanding the cellular and molecular mechanisms underlying these processes is of interest both to specialized chemoreceptive functions of that organ and, potentially, to the general physiology and pathophysiology of cellular hypoxia. We have combined cell lineage tracing technology and conditionally inactivated alleles in recombinant mice to examine the role of components of the HIF hydroxylase pathway in specific cell types within the carotid body. We show that exposure to sustained hypoxia (10% oxygen) drives rapid expansion of the Type I, tyrosine hydroxylase expressing cell lineage, with little transdifferentiation to (or from) that lineage. Inactivation of a specific HIF isoform, HIF-2α, in the Type I cells was associated with a greatly reduced proliferation of Type I cells and hypoxic ventilatory responses, with ultrastructural evidence of an abnormality in the action of hypoxia on dense core secretory vesicles. We also show that inactivation of the principal HIF prolyl hydroxylase PHD2 within the Type I cell lineage is sufficient to cause multilineage expansion of the carotid body, with characteristics resembling paragangliomas. These morphological changes were dependent on the integrity of HIF-2α. These findings implicate specific components of the HIF hydroxylase pathway (PHD2 and HIF-2α) within Type I cells of the carotid body with respect to the oxygen sensing and adaptive functions of that organ.

Sclerosing paraganglioma of the carotid body: a potential pitfall of malignancy

Paragangliomas (PGs) of the head and neck region are typically benign, slow-growing neuroendocrine tumours. At times, they may exhibit unusual histological features, such as prominent stromal sclerosis (sclerosing PG), which may raise concerns of malignancy. We describe a case of sclerosing PG of the carotid body, emphasizing the value of immunohistochemical stains for differential diagnosis. A 43-year-old woman presented with a painless lump on the neck. A magnetic resonance imaging scan demonstrated a hypervascular lesion of the carotid body, which was surgically excised. Grossly, the lesion measured 1.8 cm at maximum diameter. On microscopic examination, irregular nests and tiny bundles of neoplastic cells were found between thick bands of fibrous tissue. Focal nuclear cytomegaly and marked pleomorphism were noted. Neoplastic cells proved to be immunoreactive for chromogranin, synaptophysin and neuron specific enolase, but negative for cytokeratins, smooth muscle actin and CD34. Ultrastructurally, numerous mitochondria, rough endoplasmic reticulum structures and endocrine granules were seen in the cytoplasm of the tumour cells. On consideration of the above-mentioned clinico-pathological and ultrastructural findings a diagnosis of sclerosing PG was established. Sclerosing PG is a rare entity which may mimic a malignant neoplasm. The recognition of this unusual morphological variant of PG, together with appropriate immunostains, leads to the correct diagnosis.

Clinical and pathological analysis of malignant carotid body tumour: a report of nine cases

CONCLUSIONS

Malignant carotid body tumour (MCBT) is a clinically rare disease that often invades the carotid artery and cranial nerves. Diagnosis of malignant tumour should be based on extensive invasion of neighbouring organs and distant metastasis. Extensive resection should be undertaken early. Radiotherapy is effective, whereas chemotherapy is uncertain.

OBJECTIVE

To summarize the clinical pathological and prognostic characteristics of MCBT and explore methods for diagnosis and treatment.

MATERIALS AND METHODS

The study material comprised clinical, pathological, therapeutic and follow-up data concerning nine patients (four males, five females) with MCBT, treated at Tianjin Cancer Hospital between January 1956 and June 2006. The material was analysed retrospectively. Disease duration averaged 6.4 years. Shamblin classification was: one case, type II; 8 cases, type III. All nine patients underwent ultrasound examination, four underwent digital subtraction arteriography (DSA) and three had magnetic resonance angiography (MRA). Five patients underwent preoperative training of compression of the carotid (Matas test). Extensive resection was performed in all nine cases.

RESULTS

The carotid artery was blocked in three patients. In one of these the artery was reconstructed with a vascular prosthesis, while two underwent carotid ligation. Eight patients suffered from a cranial nerve dysfunction (defect) and two suffered postoperatively from a hoarse voice, four had a glossal deviation, five had Horner's syndrome and one had a deviation of the lip angle. One patient had a congestive cough. The histopathological diagnosis in all nine cases was MCBT. One patient had metastases to a cervical lymph node and lung and another had liver metastasis. The median follow-up period was 3 years (range 6 months to 14 years). Six patients survived surgery, of whom two underwent radiotherapy. Two patients died and one could not be traced.

Glia-like stem cells sustain physiologic neurogenesis in the adult mammalian carotid body

Neurogenesis is known to occur in the specific niches of the adult mammalian brain, but whether germinal centers exist in the neural-crest-derived peripheral nervous system is unknown. We have discovered stem cells in the adult carotid body (CB), an oxygen-sensing organ of the sympathoadrenal lineage that grows in chronic hypoxemia. Production of new neuron-like CB glomus cells depends on a population of stem cells, which form multipotent and self-renewing colonies in vitro. Cell fate mapping experiments indicate that, unexpectedly, CB stem cells are the glia-like sustentacular cells and can be identified using glial markers. Remarkably, stem cell-derived glomus cells have the same complex chemosensory properties as mature in situ glomus cells. They are highly dopaminergic and produce glial cell line-derived neurotrophic factor. Thus, the mammalian CB is a neurogenic center with a recognizable physiological function in adult life. CB stem cells could be potentially useful for antiparkinsonian cell therapy.

SDHD mutations in head and neck paragangliomas result in destabilization of complex II in the mitochondrial respiratory chain with loss of enzymatic activity and abnormal mitochondrial morphology

Hereditary head and neck paragangliomas are tumours associated with the autonomic nervous system. Recently, mutations in genes coding for subunits of mitochondrial complex II, succinate-ubiquinone-oxidoreductase (SDHB, SDHC, and SDHD), have been identified in the majority of hereditary tumours and a number of isolated cases. In addition, a fourth locus, PGL2, has been mapped to chromosome 11q13 in an isolated family. In order to characterize phenotypic effects of these mutations, the present study investigated the immunohistochemical expression of the catalytic subunits of complex II (flavoprotein and iron protein), SDH enzyme activity, and mitochondrial morphology in a series of 22 head and neck paragangliomas. These included 11 SDHD-, one SDHB-, two PGL2-linked tumours, and eight sporadic tumours. In the majority of the tumours (approximately 90%), the enzyme-histochemical SDH reaction was negative and immunohistochemistry of catalytic subunits of complex II showed reduced expression of iron protein and enhanced expression of flavoprotein. Ultrastructural examination revealed elevated numbers of tightly packed mitochondria with abnormal morphology in SDHD-linked and sporadic tumours. Immuno-electron microscopy showed localization of the flavoprotein on the remnants of the mitochondrial inner membranes, whereas virtually no signal for the iron protein was detected. These results indicate that the function of mitochondrial complex II is compromised in the majority of head and neck paragangliomas.

Carotid body tumour

A case of carotid body tumour (paraganglioma) which is both unusual and highly vascular, arising from the carotid body is reported. The patient was a 68-year-old female with a right submandibular swelling. The initial pathological diagnosis was obtained from the incisional biopsy. Carotid angiography revealed the feeding vessels arising only from the external carotid artery. The tumour was completely removed and no evidence of recurrence could be found 2-years postoperatively.

Paragangliomas of the head and neck: clinical, morphological and immunohistochemical aspects

CONTEXT

Protein marker positivity can assist in the definition of the therapeutic approach towards head and neck paragangliomas. The establishment of the therapeutic approach should incorporate the results of such an investigation.

OBJECTIVE

To establish criteria for benignity and malignancy of vagal and jugular-tympanic paragangliomas, via the study of the relationships of sex, age, tumor size, duration of complaints, site, family history, presence of metastases, treatment, histological architecture and cell type with the immunohistochemical reactions to S100 protein, chromogranin and AgKi67.

DESIGN

A retrospective study of histological and clinical records.

SETTING

The Heliópolis and Oswaldo Cruz tertiary general hospitals, São Paulo.

SAMPLE

8 cases of head and neck paragangliomas.

MAIN MEASUREMENTS

Determination of degree of positivity to paragangliomas via immunohistochemical reactions.

RESULTS

1). The protein markers for the principal cells (AgKi67 and chromogranin) were sensitive in 100% of the tumors when used together. 2). S100 protein was well identified in the cytoplasm and nucleus of sustentacular cells and underwent reduction in the neoplasias.

CONCLUSIONS

Chromogranin was proven to be a generic marker for neuroendocrine tumors; S100 protein was positive in all 8 cases and the AgKi67 had low positivity in all cases.

An unusual case of carotid body tumour

Carotid body tumours are uncommon but fascinating lesions, which arise from paraganglionic tissue at the bifurcation of the common carotid artery. We report the case history of a 40-year-old female patient who presented initially with a malignant left-sided tumour, followed by a right-sided tumour 17 years later. Although there is no known family history, it is likely, because of the bilateral tumours and the young age at presentation, that the tumour was inherited in this patient. The literature on carotid body tumours is reviewed, with particular emphasis on malignant and multiple tumours and their treatment. We discuss the recently elucidated mechanism of inheritance and its implications for affected patients and their families.

Aorticopulmonary paraganglioma (aortic body tumor): report of a case

A case of aorticopulmonary paraganglioma in a 57-year-old man is described. The tumor comprised nests of uniform cells in a fibrovascular stroma. Electron microscopy revealed abundant neurosecretory granules, and S-100 protein staining demonstrated scattered sustentacular cells at the periphery of typical zellballen. The findings in this case correlated with those of studies on the prognosis for extraadrenal paragangliomas.

Immunocytochemistry of paragangliomas--value of staining for S-100 protein and glial fibrillary acid protein in diagnosis and prognosis

Surgical specimens of 65 adrenal and 27 extra-adrenal paragangliomas, the latter comprising 11 carotid body, five jugulotympanic, one aorticopulmonary, eight aorticosympathetic and two visceral autonomic tumours, were examined immunocytochemically for the presence of glial fibrillary acid protein (GFAP) and S-100 protein. Six adrenal and four extra-adrenal (one parasympathetic and three sympathetic) neoplasms pursued a malignant clinical course. S-100 staining of sustentacular (type 2) cells was seen in both adrenal (48/65) and extra-adrenal (23/27) lesions, the 10 malignant tumours being entirely devoid of S-100 protein positive cells. GFAP positivity of type 2 cells was seen in only 16 of the extra-adrenal tumours, all of these lesions belonging to the group of benign parasympathetic paragangliomas. The presence of S-100 positive type 2 cells may thus help to exclude malignancy in individual paraganglioma cases, while GFAP positivity of such cells renders possible the correct typing of benign parasympathetic paragangliomas.

Familial multiple cervical paragangliomas: report of a kindred and review of the literature

Heredofamilial paragangliomas account for less than 10% of those arising in the head and neck. Multiplicity, multicentricity, and bilaterality is roughly three times more common than in the spontaneous variety. Not unlike other hereditary neuroendocrine tumor syndromes, familial paragangliomas appear to follow an autosomal dominant transmission, with variable penetrance and expressivity. This article describes a surgical experience with nine bilateral, multicentric cervical paragangliomas (7 carotid body, 1 vagal, and 1 sympathetic) occurring in four siblings less than 35 years of age. The literature on familial paragangliomas of the head and neck is reviewed. The postulated genetic mechanisms accounting for these and other hereditary tumors are discussed. The clinical and surgical aspects of spontaneous and familial paragangliomas are compared.

An autopsy case of malignant rhabdoid tumor arising from soft parts in the left inguinal region

An autopsy case of malignant rhabdoid tumor arising from soft parts in the left inguinal region of a 31-year-old Japanese male is reported. The tumor grew rapidly and appeared as a large mass measuring 21.5 X 16.5 cm located in the subcutaneous tissues of the lower abdominal wall. Histologically the tumor was composed of small round cells resembling rhabdomyoblasts, which showed a diffuse or alveolar arrangement. The cytoplasm of the tumor cells was eosinophilic and frequently contained round inclusion bodies, each consisting of an aggregation of globular filaments by electron microscopy. Immunohistochemistry showed the tumor cells to be positive for vimentin and keratin in the cytoplasm, but negative for actin, myoglobin and myosin. At autopsy, extensive metastatic or invasive tumors were observed mainly in the retroperitoneum and pelvic organs. The patient showed hypercalcemia which disappeared for only short periods just after surgery.

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

An immunohistochemical study on tyrosine hydroxylase (TH), a rate-limiting enzyme in the catecholamine synthesizing pathway, was made on three craniocervical region paragangliomas, two of which showed metastases to the cervical lymph nodes. In all of the original tumors, the majority of tumor cells showed positive immunostaining for TH of variable intensity in their cytoplasm regardless of their cytological features such as cellular and nuclear pleomorphism. The finding suggests that most tumor cells are capable of production of catecholamines and are derived from chief cells in the normal paraganglia. In cervical lymph nodes, however, no positive immunostaining for TH was observed in metastatic tumor cells, in contrast with the findings in the original tumors. The absence of TH immunoreactivity in metastatic tumor cells appears to be noteworthy in considering their malignant potential. Application of the TH immunohistochemistry to further cases appears important for the better understanding of this neoplasm, a catecholamine-producing tumor.

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.

Aggressive oncocytic neuroendocrine tumour ('oncocytic paraganglioma') of the cauda equina

An oncocytic neuroendocrine tumour ('oncocytic paraganglioma') of the cauda equina is reported. The tumour was predominantly intradural, with extension into and destruction of surrounding vertebral bone. The tumour had an organoid pattern, and the tumour cells had abundant non-argyrophilic eosinophilic cytoplasm. Immunocytochemical stains for neurone-specific enolase, S-100 protein, keratin and carcinoembryonic antigen were positive, but stains for glial fibrillary acidic protein were negative. On ultrastructural examination, there were numerous mitochondria and scattered 200 nm dense-core membrane-bound granules, that rarely clustered in small aggregates. Intermediate filaments were focally arranged in long compact bundles. The histogenesis of tumours reported as cauda equina paragangliomas is discussed.

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.

Argentaffin and argyrophil reactions and serotonin content of endocrine tumours

Sixty carcinoid tumours were tested in a retrospective study with an immunoperoxidase technique using a monoclonal antibody against serotonin immunoreactive sites, with argyrophil staining using the Grimelius technique, and with argentaffin staining using the Masson-Fontana technique. A good correlation between all three techniques in the diagnosis of ileal carcinoid tumour was found, but the immunoperoxidase technique showed greater sensitivity than the Masson-Fontana technique and greater specificity than the Grimelius technique in the diagnosis of foregut and hindgut carcinoid tumours. The immunoperoxidase technique with a monoclonal antibody against serotonin immunoreactive sites (YC5/45) is recommended as a sensitive and specific test for carcinoid tumours. The reactions in other endocrine tumours are also included.

Laryngeal neuroendocrine tumour with features of a paraganglioma, intracytoplasmic lumina and acinar formation

A supraglottic laryngeal neuroendocrine tumour in a 71-year-old female is presented. In addition to the typical features of extra-adrenal paragangliomas it showed unusual, numerous intracytoplasmic lumina and occasional true acini with accumulation of alcian blue and PAS positive secretory product in them which led originally to an erroneous diagnosis of metastatic adenocarcinoma. Ultrastructurally, the tumour was composed of light and dark chief cells containing varying numbers of dense-core secretory granules. Intracytoplasmic lumina and true acini contained microvilli with glycocalyceal material and varying amounts of membranous and amorphous material, possibly secreted via small, smooth-surfaced cytoplasmic vesicles but typical mucin granules were not seen. These features have not been previously described in laryngeal paragangliomas but are seen in endocrine tumours of other sites and have been used as an argument in favour of an endodermal rather than ectodermal origin for endocrine cells in those sites. Laryngeal paragangliomas are often malignant and the presence of spasmodic pain appears to be the most reliable indication of possible malignancy, histological criteria being as yet poorly defined.

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

A case of a cauda equina paraganglioma in a 13-year-old boy is described. A review of literature revealed six similar reported cases. All were intradural extramedullarly tumors located in the cauda equina-filum terminale region. In all, the presenting and dominant symptom was low back pain, while neurologic deficit was mild or absent. Excessive CSF protein levels appeared to be a characteristic feature of the disease. Histologically, the tumor displayed the typical "Zellballen" pattern, however mild nuclear pleomorphism and some mitotic figures were noted. As it is impossible to predict the biological behaviour of paragangliomas from the histologic appearance, complete surgical resection with close follow-up is indicated in such cases.