Clinical and histopathological principles for the diagnosis of a recurrent paraganglioma of the jugular foramen initially diagnosed as a middle ear adenoma: illustrative case

BACKGROUND Paragangliomas (PGLs) are rare neoplasms that may be associated with hereditary PGL syndromes and variable risk of metastasis. Middle ear adenomas are extremely rare tumors with no known hereditary predisposition and extremely low risk of metastasis. Although often easily differentiated, they may share clinical and pathological features that misdirect and confuse the diagnosis. OBSERVATIONS The authors discussed a 35-year-old woman with left-sided hearing loss and bleeding from the external ear canal who presented to an outside hospital. She underwent resection of a middle ear and mastoid mass, initially diagnosed as a middle ear adenoma with neuroendocrine features, with later mastoidectomy and ligation of the sigmoid sinus with microsurgical excision of persistent tumor in the jugular foramen and temporal bone. Histopathologically, her tumor was vascular, composed of benign-appearing epithelioid cells with “salt and pepper” neuroendocrine chromatin arranged in vague nests. Lesional cells were GATA3-immunopositive, glucagon-negative, and succinate dehydrogenase-immunonegative, consistent with PGL rather than middle ear adenoma, and required further workup for hereditary PGL syndromes. LESSONS This case demonstrates potential challenges in differentiating a PGL from a middle ear adenoma. The authors offer clinical, histopathological, and imaging principles to aid in diagnosis and workup.

Treatment with somatostatin analogues and PRRT in metastatic middle ear adenoma with neuroendocrine features

Summary Middle ear adenomas with neuroendocrine features (ANEF) are rare, with an estimated 150 reported cases. They usually pursue an indolent clinical course. Four reported cases of middle ear ANEF with distant metastases were treated with surgery, external beam radiation therapy (EBRT) and chemotherapy. To date, no successful systemic treatment for malignant behaviour of this rare tumour has been reported. Long-acting somatostatin analogues (SSAs) and peptide receptor radionuclide therapy (PRRT) have been used in well-differentiated metastatic neuroendocrine tumours (NETs), but their use has never been described in cases of metastatic middle ear ANEF. We report two patients with grade 1 middle ear ANEF treated with surgery and EBRT. They had stable disease for several years, until clinical symptoms appeared and extensive metastases were detected on 68Ga-DOTA0-Tyr3-octreotate (DOTATATE) PET/CT. Treatment with long-acting SSA was started, with stable disease for 1 year. Afterwards, despite undergoing local treatments, both patients presented progressive disease. Due to high-uptake metastases at 68Ga-DOTATATE PET/CT, both cases underwent four cycles of PRRT with 177Lu-DOTATATE, which secured disease control and improvement of quality of life in both. Similar to other well-differentiated NETs, SSA and PRRT could constitute efficacious therapeutic options in metastatic middle ear ANEF. Its neuroendocrine differentiation, potential to metastasize and somatostatin receptor type 2 expression prompt consideration and management of this disease as a neuroendocrine neoplasm. Learning points Our cases oppose the 2017 WHO classification of middle ear adenoma with neuroendocrine features as a benign disease. This entity warrants long-term follow-up, as local recurrence or persistence of disease is reported in up to 18% of surgically treated patients. PET/CT scan with 68Ga-labelled somatostatin analogues (SSA) can be used for staging of metastatic middle ear adenoma with neuroendocrine features. Unlabelled SSA and peptide receptor radionuclide therapy (PRRT) with radiolabelled SSA can be the first systemic therapeutic options for patients with advanced middle ear adenoma with neuroendocrine features.

Preoperative Diagnosis and Treatment of Middle Ear Adenoma: A Case Report and Literature Review

Most reported cases of middle ear adenoma (MEA) have focused on histopathology because MEA is usually diagnosed postoperatively, which is considered as a major setback. We focused on the surgical aspect of the disease to facilitate a preoperative diagnosis, resulting in prompt and proper treatment, without requiring a second stage of surgical treatment. In this report, we present the differential diagnoses in a 40-year-old man with MEA requiring surgical treatment. Preoperatively, the patient was suspected to have an MEA. An analysis of the surgical procedures in similar misdiagnosed tumors has enabled us to assess surgical procedures in cases wherein the preoperative diagnosis does not coincide with the postoperative histopathological results.

Middle Ear Adenoma Imitating Late Postoperative Complication

Here, we present a rare case of middle ear adenoma in a 58-year-old female, which uniquely presented as an unstable open cavity after an endaural atticoantrotomy. Immunohistochemistry confirmed that the tumor produced endocrine and exocrine secretions. The tumor was radically surgically removed.