Paraganglioma Presenting as a Nasal Septal Mass: Case Report and Literature Review

Objectives To describe a rare case of a paraganglioma arising from the nasal septum and review the diagnosis and management of paragangliomas in the nasal cavity and paranasal sinuses. Methods We present a case of a 70-year-old female presenting with persistent nasal congestion and obstruction. Nasal endoscopy revealed a posterior septal mass approaching the sphenoid sinuses and partially obstructing the nasopharynx. A biopsy of the mass was taken, and histologic analysis confirmed a diagnosis of paraganglioma. Results The patient underwent an endoscopic resection of the tumor. There has been no evidence of disease recurrence after 3 months of follow‐up. Conclusions Paragangliomas arising from the nasal septum are exceedingly rare, but should be considered in the differential diagnosis in patients presenting with nasal septal masses. These tumors are typically benign, although few cases of malignant sinonasal paragangliomas have been reported. Treatment requires surgical excision with close follow-up as several cases of tumor recurrence have been reported.


Introduction
Paragangliomas are rare, slow-growing neuroendocrine tumors arising from cells of neural crest origin. ey typically originate from the adrenal gland, but occur extraadrenally in 5-10% of cases [1]. In the head and neck region, paragangliomas make up only 0.6% of all tumors, most commonly in the carotid body and jugular-tympanic regions [1][2][3]. ough rare, there are few reported cases of paragangliomas arising in the nasal cavity and paranasal sinuses [4][5][6][7][8]. To our knowledge, there has only been one previously reported case of a paraganglioma originating from the nasal septum [8].

Case Report
A 70-year-old female complaining of persistent nasal congestion and obstruction presented to our clinic for evaluation. She denied any headache or epistaxis. Nasal endoscopy was performed which showed a posterior septal mass approaching the sphenoid sinuses bilaterally and partially obstructing the view of the nasopharynx. e overlying mucosa was intact except for a small area superiorly which showed a soft granulomatous mass protruding into the left nasal cavity. e patient was taken to the operating room for septoplasty with biopsy of the mass at an outside institution. Microscopic examination of the biopsy specimen demonstrated clusters of epithelioid-appearing cells separated by bands of fibrillary stroma. e epithelioid cells were noted to have abundant amphophilic cytoplasm, uniform, rounded nuclei with "salt and pepper" chromatin, and small nucleoli. No mitotic activity, invasion, necrosis, or calcification was seen. Immunohistochemical staining demonstrated positivity for neuron-specific enolase (NSE), chromogranin A, synaptophysin, and CD56 cell markers within the epithelioid cells. Fibrillary cells were positive for NSE, chromogranin A, S-100, glial fibrillary acid protein (GFAP), and CD56 cell markers. Based on the histological appearance and immunohistochemical staining, a diagnosis of paraganglioma was made.
e patient was referred to our institution for further management. Preoperative CT imaging showed a smoothly marginated, soft tissue density mass centered at the posterior nasal septum with extension into the nasopharynx and bulging into the right sphenoid sinus (Figure 1). Severe thinning and smooth remodeling of the anterior wall of the sphenoid sinus and anterior clivus were seen. MRI imaging demonstrated hyperintense signaling of the mass on T1weighted images with a peripheral rim of hypointense signaling on T2-weighted imaging suggestive of a capsule.
An endoscopic resection of the mass was performed. Intraoperatively, a large mass was seen in the posterior aspect of the septum, bulging into the bilateral nasal cavities and extending into the sphenoid sinuses ( Figure 2). Erosion of the bone of the rostrum and anterior face of the sphenoid were also seen. Complete resection of the mass was achieved through a posterior septectomy and bilateral sphenoidotomy with tissue removal. Postoperative histologic analysis of the specimen was consistent with a paraganglioma (Figure 3). e patient has been symptom free without local recurrence 3 months following tumor resection.

Discussion
Paragangliomas arising from the nasal cavity and nasal sinuses are extremely rare. Only 48 total cases of paragangliomas occurring in the nasal cavity or paranasal sinuses have been reported to date, occurring in patients with ages ranging between 8 and 89 years old, with an average age of 49 years old. ese tumors are slightly more prevalent amongst females (60.4%). Twelve were reported to be malignant in nature, demonstrating either intracranial extension or metastasis to the cervical lymph nodes, brain, and bone. ese masses were most frequently reported to originate from the ethmoid sinuses, middle turbinate, and maxillary sinuses. Other less common locations of origin reported include the superior and inferior turbinates, and the sphenoid and frontal sinuses. To the best of our knowledge, there has only been one other reported case of a paraganglioma originating from the nasal septum (Table 1) [8].
e most commonly reported symptoms included nasal obstruction, headache, and recurrent epistaxis. e vast majority of reported cases were functionally inactive, with no evidence of catecholamine or adrenocorticotropic hormone (ACTH) secretion. However, there have been a few reported cases of metabolically active tumors secreting ACTH and catecholamines, causing hypertension and other cushingoid features in the affected patient [12,13,30]. As such, testing for catecholamine and metanephrines is recommended in symptomatic patients [29,33]. e origin of paragangliomas in the nasal cavity and paranasal sinuses remains unclear. Although paraganglionic tissue has never been demonstrated in the nasal cavity, a wider distribution of paraganglionic tissue is thought to exist in fetuses and neonates, degenerating after birth [42,43]. Some authors have suggested that the migration of these embryonic paraganglionic cells accounts for the occurrence of paragangliomas in areas with no known paraganglionic tissue like the nasal cavity [13,29,42,44]. Additionally, it has been shown that paraganglionic tissue exists around the terminal portion of the maxillary artery in infants and could possibly represent a point of origin for paragangliomas in the nasal cavity due to its anatomic proximity [19,45]. Others have suggested that the paraganglionic tissue may exist in the pterygopalatine fossa due to the close relationship of paraganglionic tissue with arteries and cranial nerves [18,19,22].
In contrast, chondrocytes of the cartilaginous septum develop from neural crest cells between the nasal cavities by the ninth week of embryonic development [46,47]. is is evident by the expression of various neural crest stem cell markers in nasal septum progenitor cells [48]. Several studies have demonstrated that these neural crest-derived chondrocytes in an adult septum retain pluripotent properties, with the capacity for osteogenic, chondrogenic, and neurogenic differentiation [48,49]. It is possible that the neural crest origin of septal chondrocytes plays an important factor in the development of nasal septal paragangliomas.    Despite the neural crest origins of nasal chondrocytes, paragangliomas arising from the nasal septum are extremely rare.
Masses arising from the nasal septum represent a broad spectrum of diagnoses including polyps, chondromas, hematomas, and hemangiomas. Less common septal lesions include sarcomas, melanomas, and other neoplasms [46,50]. Patients with septal masses typically present with nonspecific symptoms of nasal obstruction or epistaxis, making it difficult to diagnose these masses based on clinical evaluation alone. CT imaging and MR imaging are useful tools in determining exact locations and boundaries of lesions, as well as identifying any erosion or extension into surrounding structures, though imaging features of most masses are nondiagnostic. Diagnosis of such masses requires a combination of clinical history and histopathologic findings. Although paragangliomas of the nasal septum are extremely rare, they should be included in the differential diagnosis when evaluating a septal mass. e classical histologic appearance of a paraganglioma features an alveolar pattern of well-defined clusters of epithelioid chief cells with round nuclei and eosinophilic cytoplasm. ese cells form a "zellballen" pattern of nests separated by vascular stroma and spindle-shaped sustentacular cells [28,43]. Immunohistochemical staining of paragangliomas generally demonstrates positive markers for NSE, synaptophysin, and chromogranin within the chief cells and S-100 and GFAP within the sustentacular cells [8,25,43].
Although the majority of reported nasal paragangliomas are benign, 12 of the cases presented in this review (25.0%) were reported to be malignant, demonstrating intracranial invasion and/or metastasis to the brain, cervical lymph nodes, and bones. It is widely accepted that malignancy cannot be diagnosed by histology alone, but requires evidence of bony invasion or distant metastasis [18,19,22]. Certain histological features such as mitotic figures, cellular pleomorphism, necrosis, and vascular invasion can be suggestive of malignancy, though none of these features have been shown to be reliable predictors of malignancy [19,51]. As such, evaluation with CT imaging and MRI imaging plays a key role in both localization of the primary tumor and identification of local invasion or metastasis.
Almost all of the cases presented in this review were treated surgically. Suggested management of sinonasal paragangliomas involves surgical excision with close followup, as several cases of recurrence have been reported [4,22,29]. Due to the rich vascularity of these masses, preoperative embolization of the vessels supplying the tumor has been suggested to reduce bleeding during surgery [4,22,24]. Many authors suggest the use of radiation therapy to slow the rate of recurrence, although radiation therapy alone has not been shown to be curative [3,22,33]. Chemotherapy as a primary treatment for these tumors has been shown to be largely ineffective, though 3 cases reported in this review reported the use of chemotherapy in addition to surgery and radiation therapy in the management of malignant sinonasal paragangliomas [4,22].

Conclusion
We present a rare case of a paraganglioma presenting as a septal mass. To the best of the authors' knowledge, only one other case of nasal septal paragangliomas has been reported. Clinically, these lesions cause symptoms of obstruction, congestion, headache, and epistaxis. Recognizing that paragangliomas can arise from the nasal septum is crucial to accurately diagnose these tumors when evaluating septal lesions. A diagnosis of a paragangliomas can be confirmed based on the histopathologic imaging. ese tumors are usually benign but require additional imaging as malignancy cannot reliably be ruled out on the basis of histology alone. Treatment of these tumors requires surgical resection, though radiation therapy has been to show slow growth and decrease recurrence.

Conflicts of Interest
e authors declare that there are no conflicts of interest or financial disclosures. Acknowledgments e authors thank Dr. David Yau for providing the histopathology images and Dr. John Go for reviewing the radiology images. Case Reports in Otolaryngology 5