[Biology and growth velocity of tumors of the globus jugulotympanicum and glomus caroticum]

A carcinoid tumor of the middle ear masquerading as a glomus tympanicum presenting with temporal lobe hemorrhage in a 70-year-old woman: Case report and review of the literature

BACKGROUND

Paragangliomas in the central nervous system account for 0.6% of all head and neck neoplasms, with glomus tympanicum being the most common middle ear tumor. Carcinoid tumors are neuroendocrine tumors, representing less than 1% of neuroendocrine neoplasms in the middle ear. Misdiagnoses have been reported in the literature regarding glomus and carcinoid tumors, however, none have been in the central nervous system or middle ear.

CASE DESCRIPTION

A 70-year-old female with a history of left temporal lobe tumor underwent unsuccessful resection due to intraoperative bleeding at an outside institution. However, biopsy prior to aborting the case led to the diagnosis of paraganglioma. Eight years postoperatively, the patient presented at our institution with acute confusion, aphasia, and altered mental status. Imaging revealed a 4 cm left temporal intraparenchymal hematoma at the known tumor site with concern for intracranial tumor extension. Surgical resection was performed and previous symptoms resolved. Final pathology revealed a Grade II atypical carcinoid tumor with an unusually high Ki-67 of 50%.

CONCLUSIONS

Carcinoid tumors of the middle ear constitute a differential diagnosis for patients presenting with temporal lobe hemorrhage. A combination of immunohistochemical staining with electron microscopy can assist in differentiating the tumor types. This atypical presentation for a carcinoid tumor in the middle ear suggests the need to consider carcinoid as the diagnosis in patients with a middle ear tumor invading into the temporal lobe and causing hemorrhage. These tumors may demonstrate an unusually high Ki-67 rate, in which case they should be treated aggressively.

Paragangliomas and paraganglioma syndromes

Paragangliomas are rare tumors of neural crest origin. They are benign in the majority of cases and are characterized by a strong vascularisation.

In the head and neck region they most commonly occur as carotid body tumors. Jugulotympanic and especially vagal paragangliomas are seen less frequently. Complete surgical resection represents the only curative treatment option even though resection of locally advanced tumors regularly results in lesions of the lower cranial nerves and major vessels.

Appoximately 30% of all head and neck paragangliomas (HNPs) are hereditary and associated with different tumor syndromes. The paraganglioma syndromes 1, 3 and 4 (PGL 1, 3 and 4) make up the majority of those familial cases. PGL 1 is associated with mutations of the succinate dehydrogenase subunit D (SDHD) gene, PGL 3 is caused by SDHC and PGL 4 by SDHB gene mutations. Multiple HNPs and the occurance of HNPs together with pheochromocytomas are seen in SDHD as well as SDHB mutation carriers. In patients with SDHB mutations the risk for the development of malignant paraganglial tumors is significantly higher compared to SDHC and SDHD patients as well as patients with sporadic tumors. SDHC mutation carriers almost exclusively present with benign HNP that are unifocal in the majority of cases. The role of transmission is autosomal dominant for all three symptoms. Interestingly, there is a “parent-of-origin-dependent-inheritance” in subjects with SDHD gene mutations. This means that the disease phenotype may only become present if the mutation is inherited through the paternal line. We recommend screening for mutations of the genes SDHB, SDHC and SDHD in patients with HNPs. Certain clinical parameters can help to set up the order in which the three genes should be tested.

Immunohistochemical characteristics of canine aortic and carotid body tumours

In an immunohistochemical study of 25 canine chemodectomas, 17 tumours were stained with antisera to neurone specific enolase and the same number were stained for synaptophysin; a single tumour was stained for S100. Staining for Ki-67 occurred in 18 cases; the Ki-67-labelling index and the intensity of immunostaining was increased in more pleomorphic and malignant tumours, as assessed on histological grounds. Immunohistochemistry did not aid in recognition of less well-differentiated tumours.

Biologic characteristics of paragangliomas of the nasal cavity and paranasal sinuses

Paragangliomas of the nasal cavity and paranasal sinuses are extremely rare. This study was conducted to investigate the biologic characteristics of these lesions on different molecular levels and to estimate their biologic behavior. Operative specimens of three patients who underwent surgery for a paraganglioma of the nasal cavity (one case) or paranasal sinuses (two cases) were investigated by routine histology, quantitative DNA analysis, and immunohistochemical assessment of proliferation markers (i.e., Proliferating Cell Nuclear Antigen, PCNA; Ki67-MIB-1), the expression of cell-surface antigens, which reflect the tumor-stroma interaction (i.e., CD 44 v0.4/5 and 6, CD 54, CD 106), oncogene products (nm-23; p53), and bcl-2 as a marker of apoptosis. Histologically, two tumors were paragangliomas of the adenomatous subtype, one lesion was classified as angiomatous. According to DNA analysis, aneuploid cells were detected in all tumors. Two of three paragangliomas were classified as a DNA type III pattern, implying a high percentage of aneuploid cells and an aggressive behavior. Immunohistochemically, paragangliomas of the nasal cavity showed increased scores for both proliferation markers tested, indicating a rapid growth pattern. According to the expression of cell-surface markers and oncogene products, these tumors displayed an aggressive behavior and an infiltrating growth pattern. The highest value for the parameters of quantitative DNA analysis and highest proliferation scores were found in a tumor of a patient who developed multiple tumor recurrences after radical excision of the lesion with clear margins, and finally died of disease. In conclusion, paragangliomas of the nasal cavity and paranasal sinuses examined in this study should be regarded as suspicious concerning their biologic and clinical behavior. Radical excision, and in cases with highly aggressive biology, postoperative radiation therapy are recommended. Tumor biologic examinations can help to recognize high-risk patients for developing recurrences and possibly lesions with a malignant behavior and to enhance our understanding of the biology of these extremely rare tumors of the nasal cavity and paranasal sinuses.

Paraganglioma as a systemic syndrome: pitfalls and strategies

Tumours of the neuroendocrine system in the head and neck region are mostly paragangliomas of the glomus tympanicum or jugulare, or of the carotid body. The majority of these tumours are benign, and the coexistence of multiple paragangliomas seems to be rare. Pre-operative embolization and surgery are regarded as primary therapy for these tumours. The treatment regimen in any patient depends on age, general health, hearing status and the function of the lower cranial nerves. Several presentations are possible in which paragangliomas occur as systemic disease. 1. Paragangliomas may occur bilaterally, or, in rare cases, in multiple areas. Pre-operative bilateral angiography is of utmost importance. In case of multicentricity, it might be necessary to proceed without, or just with, unilateral surgery for preservation of adjacent structures. In surgery of jugular vein paraganglioma, we usually perform a modified transmastoidal and transcervical approach with preservation of middle-ear structures and the ossicles. As an alternative or supplement to surgery, radiotherapy or definitive embolization may be used in the treatment of paragangliomas. 2. Paragangliomas may occur as multiple endocrine neoplasia (MEN) syndrome combined with medullary thyroid gland carcinoma, and, facultatively, pheochromocytoma. In these cases, endocrinological examination and magnetic resonance imaging (MRI) of the adrenal region, the thorax and the neck are required for an adequate therapeutic strategy. As MEN may be inherited, family history should be evaluated. 3. Paragangliomas can became malignant and metastasize. Thus, cervical lymph node metastases or distant metastases may occur. We recommend the removal of all ipsilateral lymph nodes and their histological examination.