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Ectopic apocrine glands as a predisposing factor for postinflammatory medial meatal fibrosis: a clinicopathologic
Gerhard Moser1, Michael Emberger, Miklós Tóth
1*Department of Otorhinolaryngology and †Department of Dermatology, Paracelsus Medical University, Salzburg, Austria.
Objective:
To illuminate pathophysiologic processes in postinflammatory medial meatal fibrosis (PMMF), a rare otologic disease of unknown etiology, which is defined by a progressive, obliterating fibrosis that affects the osseous part of the external auditory canal (EAC) exclusively.
Study Design:
Retrospective clinical and histopathologic study.
Setting:
Tertiary referral center.
Patients:
Eleven patients (4 female and 7 male subjects) who underwent surgery of the bony EAC due to PMMF (13 ears operated).
Methods:
Histologic and immunohistochemical assessment of tissue specimens obtained during surgical excision.
Main Outcome Measure:
Detection of ectopic apocrine glands and concomitant inflammatory infiltrate within tissue harvested from the osseous EAC.
Results:
Additionally to expected histologic findings, such as excessive fibrosis and a chronic inflammatory infiltrate, ectopic spread of apocrine glands was consistently detected in all of our patients.
Conclusion:
Based on our findings, we suggest that an ectopic occurrence of adnexal structures within the bony EAC may predispose susceptible individuals to the development of PMMF. To avoid postoperative recurrence due to iatrogenic spread of cutaneous adnexal structures during surgery, the split-thickness skin graft should not exceed a thickness of 0.4 mm.
Insights
Ectopic apocrine glands in the external auditory canal may cause postinflammatory medial meatal fibrosis (PMMF). Careful surgical technique, including thin skin grafts, is crucial to prevent recurrence of this rare otologic condition.
Area of Science:
- Otolaryngology
- Pathology
- Dermatology
Background:
- Postinflammatory medial meatal fibrosis (PMMF) is a rare otologic disease characterized by progressive fibrosis of the external auditory canal (EAC).
- The etiology of PMMF remains unknown, presenting a diagnostic and therapeutic challenge.
Purpose of the Study:
- To investigate the underlying pathophysiologic mechanisms of PMMF.
- To identify potential predisposing factors for the development of PMMF.
Main Methods:
- Retrospective clinical and histopathologic study at a tertiary referral center.
- Analysis of tissue specimens from 11 patients (13 ears) who underwent surgery for PMMF.
- Histologic and immunohistochemical assessment of resected tissues.
Main Results:
- Consistent detection of ectopic apocrine glands within the osseous EAC in all patients.
- Presence of excessive fibrosis and chronic inflammatory infiltrate, as expected.
- Ectopic adnexal structures were identified alongside fibrosis.
Conclusions:
- Ectopic apocrine glands in the EAC may predispose individuals to PMMF.
- Surgical management should consider the risk of iatrogenic spread of adnexal structures.
- Thin split-thickness skin grafts (≤0.4 mm) are recommended to minimize recurrence risk.
