Introduction:
We report the occurrence of an inverted papilloma (IP) in the petrous bone after endonasal
surgery.
Case report:
A 68-year-old female patient reported nasal obstruction and rhinorrhoea on her left
nose.
Endoscopic examination and CT-scans revealed her left nasal cavity to be filled with
a tumor mass.
The tumor was surgically removed completely by endonasal-endoscopic sinus surgery.
Histological examination led to the finding of an IP. The unusually large openings
of the tuba auditiva were intraoperatively free and far located from the IP. After
8 weeks the patient noticed a progressive hearing loss on her left side. A conductive
hearing loss of 40db concerning all frequencies and a dedifferentiation of the left
eardrum could be verified. CT-scans revealed the left mastoid and tympanum to be completely
obstructed. Explorative tympanoscopy confirmed IP within the petrous bone. A left
typanomastoidectomy was performed consecutively with the aim of tumor removal. Discussion
in the interdisciplinary tumor conference led to the recommendation of adjuvant radiotherapy
because of severe dysplasia. The patient refused this therapy and preferred to present
periodically to follow-up examinations.
Conclusion:
IP is a rare tumor entity representing about 0.5 to 4% of all nasal tumors. Localization
in the petrous bone is associated with a higher risk of malignancy (up to 60%) than
the endonasal localization (up to 15%). The tumor may infiltrate the middle ear via
the tuba auditiva. There exist few case reports on IP of the middle ear. It is characterized
by a locally destructive growth and a tendency towards malignant transformation, which
represents a challenge to treat by the attending ENT and other specialists.
