CONCLUSION While rare pathology of the middle ear with debatable imaging and clinical features, MeNETs are malignant tumors which may be considered as a potential di erential diagnosis for a middle ear soft tissue lesion. Paraganglioma of the middle ear, meningioma, cholesteatoma, carcinoid tumor, teratoma, and schwannoma are other possible di erential diagnoses for middle ear lesion.6,7 Preoperative diagnosis is di cult, and de nitive diagnosis will be elucidated through imaging and biopsy. Long-term follow-up is strongly advised to assess for recurrence and metastasis. REFERENCES 1. Werner RA, Solnes LB, Javadi MS, Weich A, Gorin MA, Pienta KJ, Higuchi T, Buck AK, Pomper MG, Rowe SP, Lapa C. SSTR-RADS Version 1.0 as a Reporting System for SSTR PET Imaging and Selection of Potential PRRT Candidates: A Proposed Standardization Framework. J Nucl Med. 2018 Jul;59(7):1085-1091. 2. Sandison A. Update from the 5th Edition of the World Health Organization Classi cation of Head and Neck Tumours: Tumours of the Ear. Head Neck Pathol. 2022 Mar;16(1):76- 86. 3. He S, Shi S, Qin R, Wang H, Sun Y, Zhang J, Zhang R, Wang W. Neuroendocrine neoplasms of the middle ear: report of 2 cases and review of the literature. Int J Clin Exp Pathol. 2019 Sep 1;12(9):3453-3458.
DIFFERENTIAL DIAGNOSIS 1. Paraganglioma 2. Meningioma 3. Cholesteotoma 4.
3 months later, a PET/CT Ga-68 Dotatate (a type of somatostatin receptor (SSTR) PET agent) scan demonstrated regional radiotracer uptake overlying the pterygoid with adjacent bony sclerosis, likely re ecting posttreatment changes versus residual disease. Di use heterogeneous radiotracer uptake noted throughout the liver with avidity signi cantly above liver background, compatible with biopsy-proven neuroendocrine tumor. Low-attenuation lesions were more notable in comparison to prior imaging study, concerning for disease progression. Per SSTR-RADs, the ndings of our patient’s liver on most recent PET/CT can be classi ed as SSTR-RADS-5, which both nearly de nitively con rms the spread of MeNETs into the liver and makes the patient a strong candidate for peptide receptor radionuclide therapy (PRRT).1 DISCUSSION Middle ear neuroendocrine tumors (MeNETs) are rare tumors, accounting for less than 2% of middle ear tumors.3 Etiology, nomenclature, and classi cation of these tumors have remained subject to debate.2, 3 Prior designation as middle ear adenoma has been recently updated for the 5th edition of the World Health Organization Classi cation of Head and Neck Tumours.2 Per Asa et al., the terminology adenoma does not correctly re ect potential for tumor to be invasive or even metastatic.6 Overall, MeNETs are malignant with properties that re ect their apparent mixed di erentiation. Clinically, these tumors present as nonspeci c ear mass in middle- aged patients without gender preference, with symptoms such as unilateral hearing loss and tinnitus. Pain and facial nerve paralysis are rare symptoms and may indicate malignancy. MeNETs present with unpredictable behavior – MeNETs have demonstrated both indolent growth and aggressive metastasis, with corresponding histological patterns.4 MeNETs cells are positive for high and low molecular weight keratins (AE1/ AE3, Cam5.2) and neuroendocrine markers (synaptophysin, chromogranin) as well as transcription factors INSM1, islet-1 (ISL1) and SATB2.2 MeNETs have been shown to produce hormones such as glucagon, pancreatic polypeptide, serotonin, and PYY, amongst others.2-3 As seen on cross sectional imaging, MeNETs are avascular soft tissue densities prone to osseous expansion within the middle ear space toward the ossicles. On MRI, these tumors may be iso- to hyperintense relative to white matter on T1 pre contrast and demonstrate variable enhancement.4 SSTR-RADS version 1.0 is a 5-point scale that was developed as a means of standardizing the interpretation of somatostatin receptor (SSTR) PET imaging to frame diagnosis and treatment of neuroendocrine tumors (NETs). Scores are subdivided based on uptake level, localization of uptake, or corresponding ndings on conventional imaging.1 Grading MeNETs based on the G1/G2/G3 grading system, generally utilized for other neuroendocrine tumors, is being investigated based on their similar overall behavior. 2,6 De nitive treatment is surgical resection with removal of ossicles, without adjuvant therapy.3 Disease recurrence has been reported in near 20% of cases, associated with high proliferation rates alongside metastasis.2,3
YEARS
Middle Ear Neuroendocrine Tumors (MeNETs)
5. 6.
Carcinoid Tumor
Teratoma
7. Schwannoma FINAL DIAGNOSIS Middle Ear Neuroendocrine Tumors (MeNETs) INTRODUCTION
First described in 1976 as “middle ear adenomas,” these lesions were recently redesignated as “middle ear neuroendocrine tumors (MeNETs)” due to their exocrine and neuroendocrine di erentiation, alongside their unpredictable clinical course.2,6 Typically thought to be indolent, non-invasive tumors, MeNETs have been found to recur and metastasize correlating with their proliferation rate.2 In this report, we present a case of an aggressive MeMeNET with biopsy-proven metastasis to the liver, while reviewing features of these tumors on imaging and histopathology, di erential diagnoses, and treatment options. CASE REPORT 33-year-old man presented last year with partial left facial paralysis, otitis, hearing loss, and tinnitus, and was diagnosed with Bell’s palsy at the time of initial presentation. Physical examination at a following visit demonstrated fullness in the left external auditory canal with a mass obliterating the ear drum. The patient was then scheduled for surgery. Preoperative CT of the temporal bone at that time demonstrated opaci cation of the middle ear cavity and relatively homogenous soft tissue in the medial external auditory canal with erosion of the incus and demineralization of the stapes, consistent with a left middle ear and external auditory canal soft tissue mass. The patient subsequently underwent a modi ed radical tympanomastoidectomy with facial nerve decompression and microdissection. Following a subsequent radical tympanoplasty with mastoidectomy a month after and further transtemporal craniotomy with temporalis muscle rotational pedicle flap and meatoplasty for tumor resection at the end of that year, the mass was determined to be a middle ear, mixed epithelial and neuroendocrine tumor (MeMeNET) with a Ki67 proliferation index of approximately 30%, indicating an aggressive tumor. The lesion was positive for AE1/AE3, synaptophysin, chromogranin, and NSE. Of note, portions of what appears to be a cholesteatoma were present. Fluorodeoxyglucose (FDG)-PET/CT obtained 2 months later demonstrated a 2.0 x 1.2 x 1.0 cm hypermetabolic soft tissue lesion with a SUV max 6.0 correlating with the previously identi ed enhancing mass along the medial aspect of the left lateral pterygoid muscle, alongside multiple foci of higher-than- expected radiotracer uptake within the liver, with some larger foci corresponding to areas of hypoattenuation. Given the concern for both recurrent neoplastic process and metastatic disease, the patient underwent proton therapy. Liver biopsy was conducted after a trial of proton therapy and con rmed metastasis.
50 YEAR PHYSICIANS Don Bell, MD Ronald Bombet, MD
F. Brabson Lutz, Jr., MD Brian Matherne, MD Weston Miller, Ill, MD Glenn Mills, MD Stephen Person, MD Edwin Ross, MD Robert Ryan, MD Lawrence Schneider, MD Alan Sheen, MD Charles Simonson, MD Robert Wallace, Ill, MD Kermit Walters, Jr., MD Charles Williams, Jr., MD Michael Zambie, MD
Leonard Bourgeois, MD Richard Bourgeois, MD David Bryan, MD Zack Buckalew, Ill, MD Robert Dawson, Ill, MD Daniel Dupree, MD Mary Eschete, MD Carl Fastaband Thomas Ferguson, MD Rajendra Gandi, MD Joseph Heard, MD Sheldon Johnson, MD Alfonso Lebron-Berges, MD
4. Katabi N. Neuroendocrine Neoplasms of the Ear. Head Neck Pathol. 2018 Sep;12(3):362-366.
5. Subedi N, Prestwich R, Chowdhury F, Patel C, Scarsbrook A. Neuroendocrine tumours of the head and neck: anatomical, functional and molecular imaging and contemporary management. Cancer Imaging. 2013 Oct 4;13(3):407-22. 6. Asa, S.L., Arkun, K., Tischler, A.S. et al. Middle Ear “Adenoma”: a Neuroendocrine Tumor with Predominant L Cell Di erentiation . Endocr Pathol 32, 433–441 (2021). 7. Baku M, Ueda H. A rare case of middle ear adenoma. Nagoya J Med Sci. 2014;76(3-4):355-360. ACKNOWLEDGMENTS Mitchell Ta, MD is a PGYII Resident at Riverside Community Hospital. Christian Huebner, MD is a practicing Radiologist in Southeastern Louisiana. Michelle Honda, MD is an Academic Assistant Clinical Professor of Radiology at Yale University. Jeremy Nguyen, MD FACR is clinical radiology professor within the Department of Radiology at the Tulane University Medical Center. Ryan Craig is a pathology professor within the Department of Pathology at the Tulane University Medical Center. Neel Dewan Gupta, MD is a clinical and academic musculoskeletal radiologist in New Orleans and serves as a clinical assistant professor within the Department of Radiology at the Tulane University Medical Center. Jagan Gupta, MD is a neuroradiologist at the Southeast Louisiana Veterans Health Care System. Joshua Diener is a 4rth year medical student at the Tulane University School of Medicine. Donald Olivares, Digital Imaging Specialist and Graphic Designer.
In Memoriam
James Phillips, MD Frederick Price, MD Stephen Breaud, MD Pedro Cazabon, MD Prentiss Smith, Jr., MD
William Bundrick, Sr., MD John Finn, Jr., MD William Glenn, MD Rozelle Hahn, MD Thomas Kramer, MD
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J LA MED SOC | VOL 177 | FALL 2025
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