Abstract
Objective
This study aimed to analyze the clinical features of patients who underwent surgery for secondary acquired cholesteatoma (SAC).
Materials and methods
The subjects were 30 patients who underwent surgery for SAC in 30 ears. We investigated the age distribution, sex, tympanic membrane (TM) findings, temporal bone pneumatization, morphology of TM epidermis invasion, extent of cholesteatoma invasion, ossicular erosion, surgical methods and surgical results.
Results
There were 10 males (33.3%) and 20 females (66.6%), with a mean age 54.9 years. The TM perforation was medium-sized or larger in 27 ears (90%). Temporal bone pneumatization was poor or bad in 90% (18/20) of the evaluated ears. The cholesteatoma invaded from the malleus manubrium to the promontory in 23 ears (76.7%). There were no patients in whom the cholesteatoma invaded the antrum or mastoid. The ossicles were affected in 19 ears (63.3%). Ossiculoplasty with a columella on the stapes was the most frequent procedure, performed for 16 ears (53.3%). There were no hearing results with a postoperative air-bone gap of more than 31 dB.
Conclusions
Although SAC is rare, it is important for the clinician to keep this type of cholesteatoma in mind.
1
Introduction
Most cases of acquired middle ear cholesteatoma are considered to develop due to retraction or adhesion of the tympanic membrane (TM). However, there are some cases in which the TM epidermis invades the medial surface of the TM from the margin of its perforation, without any retraction or adhesion. This is called secondary acquired cholesteatoma (SAC). To the best of our knowledge, few studies of SAC have been reported in the literature. Although SAC is quite rare, it is an actual clinical entity and clinicians must be aware of its existence.
The objective of this study was to analyze the clinical features of patients who underwent surgery for SAC.
2
Materials and methods
The subjects were 30 patients with SAC in 30 ears, for which operations (primary surgery) were performed at the Jikei University Hospital, Tokyo, Japan, from July 1989 through December 2011. The patients were followed for at least 1 year after their last operation. The presence or absence of a history of otitis media was not taken into consideration.
There are no definitive criteria for SAC. We used the following criteria to diagnose SAC in this study: (1) presence of perforation of the pars tensa, without any TM retraction or adhesion; (2) TM epidermis invading from the margin of the perforation to the medial surface of the TM; and (3) removal of the invaded TM epidermis requires a surgical procedure in the tympanic cavity.
We analyzed the following features: the age distribution, sex, TM findings, temporal bone pneumatization, morphology of TM epidermis invasion, extent of the cholesteatoma invasion, ossicular erosion, surgical methods and surgical results.
2
Materials and methods
The subjects were 30 patients with SAC in 30 ears, for which operations (primary surgery) were performed at the Jikei University Hospital, Tokyo, Japan, from July 1989 through December 2011. The patients were followed for at least 1 year after their last operation. The presence or absence of a history of otitis media was not taken into consideration.
There are no definitive criteria for SAC. We used the following criteria to diagnose SAC in this study: (1) presence of perforation of the pars tensa, without any TM retraction or adhesion; (2) TM epidermis invading from the margin of the perforation to the medial surface of the TM; and (3) removal of the invaded TM epidermis requires a surgical procedure in the tympanic cavity.
We analyzed the following features: the age distribution, sex, TM findings, temporal bone pneumatization, morphology of TM epidermis invasion, extent of the cholesteatoma invasion, ossicular erosion, surgical methods and surgical results.
3
Results
3.1
Age distribution and sex
There were 10 males (33.3%) and 20 females (66.6%), with a mean age of 54.9 years (range, 27–71 years), with the largest number being 50 to 59 years of age ( Fig. 1 ). Twenty-two patients (73.3%) were 50 years or older.
3.2
Size of tympanic membrane perforation
The TM perforation was assessed as total (almost no remaining, intact TM) in 10 of the 30 ears (33.3%), large (involving more than 3 tympanic quadrants) in 5 (16.7%), medium (involving 2 tympanic quadrants) in 12 (40%) and small (involving a single tympanic quadrant) in 3 (10%).
Thus, the perforation was medium or larger in size in 90% (27/30 ears) of the patients.
3.3
Preoperative diagnosis
Based on the preoperative TM findings or CT findings, 19 of the 30 (63.3%) ears were diagnosed as cholesteatoma, and 11 (36.7%) were diagnosed as chronic otitis media or tympanosclerosis without cholesteatoma.
3.4
Preoperative findings of calcification
Calcification surrounding the TM or the ossicles was found in 12 (40%) of the 30 ears. Seven of those 12 ears had been diagnosed as chronic otitis media or tympanosclerosis without cholesteatoma preoperatively.
3.5
Temporal bone pneumatization
In this study, the degree of temporal bone pneumatization was classified as good (good development of air cells), poor (suppressed development of air cells), or bad (no development of air cells). The result of classification in 20 patients for whom data were available was good in 2 (10%), poor in 11 (55%) and bad in 7 (35%).
3.6
Morphology of TM epidermis invasion
Based on the site and pattern of invasion of TM epidermis, the morphology of the cholesteatomas was classified into two types. In type 1, the TM epidermis has invaded from the malleus manubrium to the promontory. In type 2, the TM epidermis has invaded from the edge of the perforation along the inner surface of the TM. Twenty-three of the 30 ears (76.7%) were classified as type 1, and the remaining 7 as type 2 (23.3%).
3.7
Extent of cholesteatoma invasion
Based on our analysis of the surgical findings, we classified the extent of invasion by the cholesteatoma into three types: localized within the inner surface of the TM (the cholesteatoma invasion ends at the inner surface of the TM), extends to the mesotympanum, or reaches the attic. There were no ears in which the cholesteatoma invaded to the antrum or mastoid.
In 17 (73.9%) of the 23 ears with type 1 SAC, the cholesteatoma reached the attic. On the other hand, in 6 of the 7 (85.7%) type 2 ears, the cholesteatoma did not invade past the mesotympanum. That is, it was localized within the inner surface of the TM in 3 ears and invaded to the mesotympanum in 3 ears. In the final (14.3%) type 2 ear, the cholesteatoma reached the attic ( Table 1 ).
| Extent of cholesteatoma invasion | Type 1 23 ears | Type 2 7 ears | Total 30 ears |
|---|---|---|---|
| Localized within the inner surface of the TM | 2 (8.7%) | 3 (42.8%) | 5 (16.7%) |
| Extending to the mesotympanum | 4 (17.4%) | 3 (42.8%) | 7 (23.3%) |
| Reaching the attic | 17 (73.9%) | 1 (14.3%) | 18 (60%) |
3.8
Ossicular erosion
Table 2 shows the findings regarding ossicular erosion. The ossicles were affected in 19 (63.3%) of the 30 ears. In particular, there was some destruction of the incus in 18 ears (60%).
