Adenomatous tumors of the middle ear

Middle ear adenoma: Cytohistologic features and differential diagnosis

Middle ear adenomas are rare, low grade glandular neoplasms with epithelial and neuroendocrine components and with varying patterns of differentiation. Due to the rarity of this tumor, there is a dearth of publications detailing the cytological features. We herein review our institution's pathological database for cytological material between 1992 and 2022 for MEA specimens and discuss possible differential diagnoses based on clinical, pathological, and cytologic data and material.

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.

Adenomatous Neuroendocrine Tumors of the Middle Ear in a Young Man With Conductive Hearing Loss

ABSTRACT

Neuroendocrine neoplasms of the ear pose a diagnostic challenge because clinical symptoms are no specific. Definite diagnosis is made by histopathological analysis with immunohystochemical evalutation. Therapy consists in a complete surgical resection. Controversial terminology of the neoplasm arises from the differentiation of these tumors composed of both endocrine and exocrine glands. Middle ear localization is an extremely rare presentation but less aggressive than gastrointestinal tract or lung localizations which are the most frequent. Radio-diagnostic analyses are necessary follow-up for preventing or detecting recurrence or metastasis. The authors present a case of neuroendocrine tumor of the middle ear in a young male of 37 years old who presented unilateral right hearing loss and tinnitus. A transcanal tympanoplasty was performed. There were no intraoperative complications and the postoperative period was uneventful.

Primary carcinoid tumor in the external auditory canal

A 39-year-old man visited the department of otolaryngology due to an ongoing hearing disturbance that had lasted for 1 year. Temporal bone computed tomography revealed soft tissue density nearly obliterating the left external auditory canal (EAC). The mass was composed of sheets of round tumor cells containing moderate amounts of fine granular cytoplasm and salt and pepper chromatin. Neither mitosis nor necrosis was found. The Ki-67 proliferation index was less than 2%. Cells were positive for CD56 and synaptophysin but negative for chromogranin, cytokeratin (CK) 20, and CK7. Based on these findings, the tumor was diagnosed as a carcinoid tumor, well differentiated neuroendocrine carcinoma, grade 1 (G1) according to current World Health Organization (WHO) classification of head and neck tumors; and a neuroendocrine tumor, G1 according to neuroendocrine neoplasm (NEN)-2018 WHO standard classification. He remained free of local recurrence and metastasis after 20 months of follow up. To date, only six cases of primary NENs in the EAC have been reported. Metastatic tumor should be included in the differential diagnoses. Because of its rarity, the prognosis and treatment have not yet been clarified.

[Neuroendocrine neoplasms of the auditory, olfactory, and visual sensory organs]

Neuroendocrine neoplasms (NENs) are infrequent in sensory organs. There are well-differentiated neuroendocrine neoplasms that should be classified as neuroendocrine tumors, in analogy to their gastrointestinal counterparts, however the nomenclature is inconsistent. The best defined entities are neuroendocrine tumors in the middle ear and ectopic pituitary adenoma in the sphenoid region. Poorly differentiated NENs most often arise in the olfactory organ and nasal cavity that are represented by olfactory neuroblastomas and poorly differentiated neuroendocrine carcinomas. They have several mimickers such as the sinonasal undifferentiated carcinoma, poorly differentiated squamous cell carcinoma, mucosal malignant melanoma, rhabdomyosarcoma, Ewing sarcoma/primitive neuroectodermal tumor and non-Hodgkin lymphoma.

Ceruminous Neoplasms of the Ear

Ceruminous glands are modified apocrine glands located in the external auditory canal (EAC). Neoplastic lesions arising from these glands are rare in humans and constitute a major differential diagnosis for glandular neoplasms of the EAC. Due to anatomic restrictions, benign and malignant neoplasms present with similar symptoms and to some extent even comparable radiologic features, particularly when the tumors are localized. Biopsies are frequently limited by small size, fragmentation and improper anatomic and architectural orientation, thereby hampering our ability to appreciate the relationship of peripheral edges of the tumor to the surrounding tissue. Benign and malignant tumors may also have overlapping histomorphologic features, which further magnifies the challenges in accurate diagnosis and management strategies. This article summarizes the salient clinical, radiologic and histologic features of common ceruminous gland tumors, in addition to discussing features that can aid in differentiating ceruminous tumors from other EAC tumors and to distinguish benign from malignant entities.

Neuroendocrine Neoplasms of the Ear

Neuroendocrine neoplasms of the ear are uncommon primary tumors. There is a reported debate in the literature as to the true nature of these tumors and how to classify them. However, there is a kind of consensus that they can represent a spectrum of a common entity with dual glandular and neuroendocrine differentiation. The differential diagnosis of these tumors is broad but their morphologic, immunohistochemical, and radiographic features help to differentiate them from other entities. The tumors have mostly bland histology and indolent biological behavior, yet they may recur and metastasize. It is important to accurately recognize these tumors in order to perform the right management and limit their morbidity. In this article, we review the pathogenesis, histology, immunohistochemical features of neurornedocrine neoplasms of the ear and we discuss their differential diagnosis, clinical behavior and management.

[The tumors of the ear]

Any cutaneous lesion of the outer ear must be managed jointly by a dermatologist and an ENT, regardless of the age of the patient. The presence of a malignant cutaneous carcinoma (Squamous cell carcinoma or melanoma) of the pavilion requires a minimum extension assessment by a cervical ultrasound, CT-scan and MRI will be prescribed according to the degree of infiltration and the presence of clinics signs (lymphadenopathy, facial paralysis, cognitive impairment). A polyp of the external auditory meatus must be systematically biopsied in consultation and, if necessary, in the operating room with fresh anatomopathological analysis. Any "otitis externa", which does not progress favorably under local treatment, must lead to eliminate a tumoral pathology of the external acoustic meatus or of the middle ear. Any suspicion of cholesteatoma should lead to an ENT consultation to confirm the diagnosis and consider its treatment to limit the auditory dysfunction. Any unilateral neurosensorial hearing loss or unilateral vestibular involvement with normal otoscopy should lead to eliminate a inner ear tumor by an MRI of the inner ear and the ponto-cerebellar angle in millimeter sections.

Adenomatous Tumors of the Middle Ear: A Literature Review

Introduction  Neuroendocrine adenomas of the middle ear (NAME) are uncommon causes of middle ear masses. Mostly limited to case reports and small series, the literature is poor in providing an overall assessment of these tumors. Objective  To review the current literature about all aspects of the disease, including its etiology, clinical manifestations, diagnosis, and treatment. Data Synthesis  The pathogenesis of adenomatous tumors of the middle ear is not clear yet. One potential explanation is that an undifferentiated pluripotent endodermal stem cell may still be present in the middle ear mucosal surface, and may be the origin of the tumors. It typically appears as a nonspecific retrotympanic mass. The average age of onset for the disease is the fifth decade, and the most common clinical symptom is conductive hearing loss. Malign behavior is rare. There are numerous differential diagnoses of NAME. The final diagnosis depends on microscopic findings. The preoperative evaluation should include the use of computed tomography and magnetic resonance imaging. The adjunctive therapy of middle ear adenomatous tumors with radiotherapy, chemotherapy or somatostatin analogs is generally not recommended. Conclusion  There is still much debate on pathogenesis and classification of NAME. Saliba's classification is currently the most complete and preferable one. Aggressive surgical procedure with ossicular chain excision is the gold standard treatment. Follow-up with physical and radiological exams is mandatory, particularly if the first procedure was conservative, without the removal of the encased ossicles.

Endoscopic Management of Middle Ear and Temporal Bone Lesions

Tantamount to the management of temporal bone neoplasms is the ability to visualize the pathology and its relationship with the numerous critical structures housed therein. Transcanal endoscopic ear surgery provides the surgeon with an unparalleled view of the entire middle ear. This article presents the latest information on the usefulness of transcanal endoscopic ear surgery in the management of middle ear and temporal bone neoplasms.