Background
These tumors arise within the middle ear and present with conductive deafness and rarely with perforation of the eardrum. It is a circumscribed tumor that usually is easily removed by the surgeon though occasional cases may entrap the ossicles. They are uncommon and arise in both sexes equally with a wide age range of 14-80 years, with a mean of 40 years.
Under the microscope, there are back to back glands ranging from a solid to trabecular arrangement lined by low cuboidal to columnar cells. The stroma is loose to edematous to occasionally fibrotic and dense. One interesting finding is neuroendocrine differentiation within these tumors, confirmed by both electron microscopy and by immunohistochemistry. Currently, it is believe that tumors previously diagnosed as carcinoid tumors are probably middle ear adenomas with neuroendocrine differentiation.
OUTLINE
HISTOPATHOLOGY CHARACTERIZATION
Adenoma versus Carcinoid Tumor of the Middle Ear: a Study of 48 Cases and Review of the Literature.Torske KR, Thompson LD.
Department of Endocrine and Otorhinolaryngic-Head and Neck Pathology, Armed Forces Institute of Pathology, Washington, D.C.
Mod Pathol 2002 May;15(5):543-55 Abstract quote Carcinoid tumors and adenomas of the middle ear are rare neoplasms of indeterminate relationship to one another. Indeed, the literature is devoid of a large comprehensive series that evaluates the clinical, histologic, and immunophenotypic features of these tumors and their potential relationship.
Forty-eight cases of middle ear adenoma between 1970 and 1995 were identified in the files of the Armed Forces Institute of Pathology. All cases were evaluated for cytomorphology and architectural pattern, in addition to their reactivity with various immunohistochemical reagents.
Clinical follow-up was also obtained. A comprehensive review of the literature was performed with an eye toward correlating any distinct differences or similarities between carcinoid tumors and adenomas of the middle ear. The patients included 21 women and 27 men, aged 20 to 80 years (mean, 45.0 y). Patients experienced hearing loss, mass, and/or pain for a mean duration of 1.7 years. The mean tumor size was 0.8 cm, with six tumors extending beyond the middle ear. Histologically, the tumors were moderately cellular and unencapsulated, arranged in glandular, trabecular, and solid patterns composed of small cells with "salt and pepper" nuclear chromatin distribution. The tumor cells were immunoreactive with keratin, keratin 7, chromogranin, and human pancreatic polypeptide. All patients had surgery. No patients died with their disease (mean follow-up, 15.7 y). Eight patients developed recurrences that were treated surgically and were without evidence of disease at last follow-up (mean, 15.1 y).
Our study and the review of the literature showed adenomas and carcinoid tumors of the middle ear to be essentially indistinguishable benign tumors. Middle ear adenoma most correctly describes their morphologic features and clinical behavior, although neuroendocrine adenoma of the middle ear may be a more accurate designation.
VARIANTS CUTANEOUS NEUROENDOCRINE ADENOMA
- Cutaneous neuroendocrine adenoma: an uncommon neoplasm.
Mahalingam M, Kveaton JF, Bhawan J.
UMass Memorial Medical Center, Memorial Campus, Worcester, MA, USA.
J Cutan Pathol. 2006 Apr;33(4):315-7. Abstract quote
Background: Cutaneous neuroendocrine neoplasms are typically malignant. Benign cutaneous neuroendocrine tumors are uncommon.
Methods: We report the case of a 32-year-old female who presented with a granular mass in the right external auditory canal.
Results: Microscopic examination of a shave biopsy revealed a poorly circumscribed neoplasm with glandular differentiation. While cytologic atypia and mitotic activity were not evident, pagetoid spread was observed. Immunohistochemistry was indicative of neuroendocrine origin.
Conclusions: This case report of neuroendocrine adenoma indicates that this entity should be entertained in the repertoire of conditions affecting the external ear.
DIFFERENTIAL DIAGNOSIS KEY DIFFERENTIATING FEATURES OTITIS MEDIA WITH GLANDULAR METAPLASIA Never forms a distinct tumor mass
Goblet cells abundant
No diffuse sheets of solid clusters of epithelial cells
Inflammed stromaPLEOMORPHIC ADENOMA
Acta Cytol. 1999 May-Jun;43(3):489-91. Abstract quote
BACKGROUND: Pleomorphic adenoma (PA) arising in the external auditory canal (EAC) is a very rare neoplasm, thought to be derived from ceruminous glands.
CASE: A 43-year-old male presented with a slowly growing mass in the right EAC. Clinical and radiologic examinations showed a well-circumscribed tumor limited to the EAC, without a connection to the parotid gland. Fine needle aspiration cytology (FNAC) revealed the typical cytologic findings of PA. The diagnosis was confirmed by histologic examination.
CONCLUSION: This case illustrates that together with clinical and radiologic findings, primary PA of the EAC can confidently be diagnosed by FNAC.Henry JB. Clinical Diagnosis and Management by Laboratory Methods. Twentieth Edition. WB Saunders. 2001.
Rosai J. Ackerman's Surgical Pathology. Ninth Edition. Mosby 2004.
Sternberg S. Diagnostic Surgical Pathology. Fourth Edition. Lipincott Williams and Wilkins 2004.
Robbins Pathologic Basis of Disease. Seventh Edition. WB Saunders 2005.
DeMay RM. The Art and Science of Cytopathology. Volume 1 and 2. ASCP Press. 1996.
Weedon D. Weedon's Skin Pathology Second Edition. Churchill Livingstone. 2002
Fitzpatrick's Dermatology in General Medicine. 6th Edition. McGraw-Hill. 2003.
Weiss SW and Goldblum JR. Enzinger and Weiss's Soft Tissue Tumors. Fourth Edition. Mosby 2001.
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Last Updated April 26, 2006
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