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Neuroendocrine adenoma of the middle ear
Neuroendocrine adenoma of the middle ear BENJAMIN F. AQUINO,
MD,
RAKESH K. CHANDRA,
MD,
G. KENNETH HAINES,
MD,
and ALAN G. MICCO,
MD,
Chicago, Illinois
M iddle
ear adenoma is a recently described pathologic entity, first reported by Derlacki and Barney1 in 1976. Since that time, these tumors have been established as the most common “nonglomus tumors” of the middle ear, but they are still extremely rare occurrences.2 We add the description of a new case to the literature and note the changing categorization of these tumors. CASE REPORT A 28-year-old woman with no significant past medical history presented to the otology clinic with a unilateral conductive hearing loss and otalgia that had progressed during the previous 6 months despite antibiotic treatment by her primary care physician. She denied vertigo, tinnitus, otorrhea, or previous history of otitis media. Her examination was notable for an opaque tympanic membrane with fullness in the area of Prussak’s space. There was no evidence of tympanic membrane perforation or retraction pocket. The canal was normal, and facial nerve function was intact. A computed tomography scan of the temporal bone was obtained (Fig 1), revealing a mass that filled the middle ear, mastoid, and epitympanum. This was thought to represent a cholesteatoma, although erosion of the ossicles or scutum was not apparent. The patient underwent a tympanomastoidectomy. The mastoid was found to contain strawcolored fluid, without trabecular destruction or evidence of cholesteatoma. Entry into the aditus and middle ear revealed a pale mass with gelatinous consistency that was adherent to the ossicles and mastoid air cells. This prompted an intraopFrom the Departments of Otolaryngology-Head and Neck Surgery (Drs Aquino, Chandra, and Micco) and Pathology (Dr Haines), Northwestern University School of Medicine. Reprint requests: Benjamin F. Aquino, MD, 303 E Chicago Ave, Searle Building, 12-561, Chicago, IL 60611. Otolaryngol Head Neck Surg 2002;127:477-9 Copyright © 2002 by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. 0194-5998/2002/$35.00 ⫹ 0 23/4/128902 doi:10.1067/mhn.2002.128902
Fig 1. Coronal computed tomography scan of the temporal bone. Note the soft tissue mass filling the middle ear space. The scutum is sharp, and the ossicular mass is well mineralized.
erative frozen section, which demonstrated the mass to be an infiltrating tumor with adenomatous features. The tumor was debulked and sent for permanent section. The patient was notified of the unusual findings and informed that radical surgical excision was required. Permanent section was consistent with adenoma of the middle ear (Fig 2). Immunohistochemically, the cells exhibited strong expression of chromogranin and synaptophysin (Fig 3), indicative of neuroendocrine differentiation. Subsequently, the patient underwent uncomplicated “modified radical” mastoidectomy with tumor resection. DISCUSSION Several authors have noted the difficulty that pathologists and otolaryngologists alike have had in assigning histologic classification to adenomatous middle ear tumors.2 Previously, Benecke et al3 proposed subtyping these neoplasms as either mixed or papillary. By this description, the former contain a mixture of glandular elements, sheets, nests, and cords. Mixed adenomas are typically confined to the middle ear and mastoid and rarely involve the facial nerve. In contrast, tumors with a 477
478 AQUINO et al
Otolaryngology– Head and Neck Surgery November 2002
Fig 2. Routine section (magnification ⫻100) revealing uniform polygonal cells organized into sheets and glandular forms, consistent with an adenoma.
Fig 3. Immunohistochemical staining revealing strong expression of synaptophysin (magnification ⫻100).
papillary pattern are more destructive, involving the petrous apex, the middle or posterior cranial fossae, and the facial nerve. More recent reports have hypothesized that middle ear adenomas arise from paraganglionic tissue that undergoes glandular and/or neuroendocrine differentiation.4 Lesions that were previously classified as middle ear carcinoids are currently also considered within the spectrum of middle ear adenomas. It is possible that previously reported middle ear adenomas also originated from neu-
roendocrine tissue, although immunohistochemical confirmation was not available at the time of those writings. The present case appears to exemplify a middle ear adenoma of neuroendocrine origin, based on the immunohistochemical findings. Given the rarity of these tumors, the diagnosis of middle ear adenoma is often delayed. The 2 sexes are affected equally, and the lesion may occur over a wide range of ages. The typical presenting symptoms are hearing loss, pain, and
Otolaryngology– Head and Neck Surgery Volume 127 Number 5
otorrhea. Although many of these tumors follow a slow and benign course, bony erosion and facial nerve dysfunction seem to indicate a poor prognosis.4 Part of the management dilemma in these cases has been whether to judge the tumor’s malignant potential by cellular histology or by bony involvement. Benecke et al3 suggested that malignant cells exhibit increased mitotic activity and nuclear atypia, whereas Hyams and Michaels5 proposed that bony invasion is pathognomonic for malignancy. Further confounding the issue, even tumors demonstrating aggressive histologic features, such as bone absorption or cellular atypia, may behave in a benign manner.4,5 Although carcinoid-like middle ear lesions may be locally aggressive, and some consider them malignant, they tend to grow more slowly and metastasize less often than do other malignant tumors.2 The exact treatment for middle ear adenomas must be individualized because specific protocols have not been established for these un-
AQUINO et al 479
common neoplasms. In general, complete excision is required, and the patient must be followed closely for possible recurrent disease. In the present case, resection was accomplished through “canal wall down modified” radical mastoidectomy. High-grade, recurrent, or advanced lesions, however, may require temporal bone resection with or without lateral skull base approaches.2 REFERENCES
1. Derlacki EL, Barney PL. Adenomatous tumors of the middle ear and mastoid. Laryngoscope 1976;86:1123-35. 2. Wackym PA, Friedman I. Unusual tumors of the middle ear and astoid. In: Tumors of the middle ear and temporal bone, Jackler RJ, Driscoll CL, editors. Philadelphia: Lippincott Williams and Wilkins; 2000. p. 128-45. 3. Benecke TE, Noel FL, Carberry JN, et al. Adenomatous Tumors of the middle ear and mastoid. Am J Otol 1990; 11:20-6. 4. Amble FR, Harner SG, Weiland LH, et al. Middle ear adenoma and adenocarcinoma. Otolaryngol Head Neck Surg 1993;109:871-6. 5. Hyams VJ, Michaels L. Benign adenomatous neoplasm (adenoma of the middle ear). Clin Otolaryngol 1976;1:1726.
MD,
RAKESH K. CHANDRA,
MD,
G. KENNETH HAINES,
MD,
and ALAN G. MICCO,
MD,
Chicago, Illinois
M iddle
ear adenoma is a recently described pathologic entity, first reported by Derlacki and Barney1 in 1976. Since that time, these tumors have been established as the most common “nonglomus tumors” of the middle ear, but they are still extremely rare occurrences.2 We add the description of a new case to the literature and note the changing categorization of these tumors. CASE REPORT A 28-year-old woman with no significant past medical history presented to the otology clinic with a unilateral conductive hearing loss and otalgia that had progressed during the previous 6 months despite antibiotic treatment by her primary care physician. She denied vertigo, tinnitus, otorrhea, or previous history of otitis media. Her examination was notable for an opaque tympanic membrane with fullness in the area of Prussak’s space. There was no evidence of tympanic membrane perforation or retraction pocket. The canal was normal, and facial nerve function was intact. A computed tomography scan of the temporal bone was obtained (Fig 1), revealing a mass that filled the middle ear, mastoid, and epitympanum. This was thought to represent a cholesteatoma, although erosion of the ossicles or scutum was not apparent. The patient underwent a tympanomastoidectomy. The mastoid was found to contain strawcolored fluid, without trabecular destruction or evidence of cholesteatoma. Entry into the aditus and middle ear revealed a pale mass with gelatinous consistency that was adherent to the ossicles and mastoid air cells. This prompted an intraopFrom the Departments of Otolaryngology-Head and Neck Surgery (Drs Aquino, Chandra, and Micco) and Pathology (Dr Haines), Northwestern University School of Medicine. Reprint requests: Benjamin F. Aquino, MD, 303 E Chicago Ave, Searle Building, 12-561, Chicago, IL 60611. Otolaryngol Head Neck Surg 2002;127:477-9 Copyright © 2002 by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. 0194-5998/2002/$35.00 ⫹ 0 23/4/128902 doi:10.1067/mhn.2002.128902
Fig 1. Coronal computed tomography scan of the temporal bone. Note the soft tissue mass filling the middle ear space. The scutum is sharp, and the ossicular mass is well mineralized.
erative frozen section, which demonstrated the mass to be an infiltrating tumor with adenomatous features. The tumor was debulked and sent for permanent section. The patient was notified of the unusual findings and informed that radical surgical excision was required. Permanent section was consistent with adenoma of the middle ear (Fig 2). Immunohistochemically, the cells exhibited strong expression of chromogranin and synaptophysin (Fig 3), indicative of neuroendocrine differentiation. Subsequently, the patient underwent uncomplicated “modified radical” mastoidectomy with tumor resection. DISCUSSION Several authors have noted the difficulty that pathologists and otolaryngologists alike have had in assigning histologic classification to adenomatous middle ear tumors.2 Previously, Benecke et al3 proposed subtyping these neoplasms as either mixed or papillary. By this description, the former contain a mixture of glandular elements, sheets, nests, and cords. Mixed adenomas are typically confined to the middle ear and mastoid and rarely involve the facial nerve. In contrast, tumors with a 477
478 AQUINO et al
Otolaryngology– Head and Neck Surgery November 2002
Fig 2. Routine section (magnification ⫻100) revealing uniform polygonal cells organized into sheets and glandular forms, consistent with an adenoma.
Fig 3. Immunohistochemical staining revealing strong expression of synaptophysin (magnification ⫻100).
papillary pattern are more destructive, involving the petrous apex, the middle or posterior cranial fossae, and the facial nerve. More recent reports have hypothesized that middle ear adenomas arise from paraganglionic tissue that undergoes glandular and/or neuroendocrine differentiation.4 Lesions that were previously classified as middle ear carcinoids are currently also considered within the spectrum of middle ear adenomas. It is possible that previously reported middle ear adenomas also originated from neu-
roendocrine tissue, although immunohistochemical confirmation was not available at the time of those writings. The present case appears to exemplify a middle ear adenoma of neuroendocrine origin, based on the immunohistochemical findings. Given the rarity of these tumors, the diagnosis of middle ear adenoma is often delayed. The 2 sexes are affected equally, and the lesion may occur over a wide range of ages. The typical presenting symptoms are hearing loss, pain, and
Otolaryngology– Head and Neck Surgery Volume 127 Number 5
otorrhea. Although many of these tumors follow a slow and benign course, bony erosion and facial nerve dysfunction seem to indicate a poor prognosis.4 Part of the management dilemma in these cases has been whether to judge the tumor’s malignant potential by cellular histology or by bony involvement. Benecke et al3 suggested that malignant cells exhibit increased mitotic activity and nuclear atypia, whereas Hyams and Michaels5 proposed that bony invasion is pathognomonic for malignancy. Further confounding the issue, even tumors demonstrating aggressive histologic features, such as bone absorption or cellular atypia, may behave in a benign manner.4,5 Although carcinoid-like middle ear lesions may be locally aggressive, and some consider them malignant, they tend to grow more slowly and metastasize less often than do other malignant tumors.2 The exact treatment for middle ear adenomas must be individualized because specific protocols have not been established for these un-
AQUINO et al 479
common neoplasms. In general, complete excision is required, and the patient must be followed closely for possible recurrent disease. In the present case, resection was accomplished through “canal wall down modified” radical mastoidectomy. High-grade, recurrent, or advanced lesions, however, may require temporal bone resection with or without lateral skull base approaches.2 REFERENCES
1. Derlacki EL, Barney PL. Adenomatous tumors of the middle ear and mastoid. Laryngoscope 1976;86:1123-35. 2. Wackym PA, Friedman I. Unusual tumors of the middle ear and astoid. In: Tumors of the middle ear and temporal bone, Jackler RJ, Driscoll CL, editors. Philadelphia: Lippincott Williams and Wilkins; 2000. p. 128-45. 3. Benecke TE, Noel FL, Carberry JN, et al. Adenomatous Tumors of the middle ear and mastoid. Am J Otol 1990; 11:20-6. 4. Amble FR, Harner SG, Weiland LH, et al. Middle ear adenoma and adenocarcinoma. Otolaryngol Head Neck Surg 1993;109:871-6. 5. Hyams VJ, Michaels L. Benign adenomatous neoplasm (adenoma of the middle ear). Clin Otolaryngol 1976;1:1726.