A case of salivary gland choristoma of the middle ear By DORIN HOCIOTA and TRAIAN ATAMAN (Bucharest) Ix the course of otological investigations there are occasional surprises. We present here a rare case of congenital malformation which could not be diagnosed until after surgery and later investigation. Patient B.K., a lawyer, aged 50 years, was admitted to our department on 17 September 1969, with a mixed type of hearing loss and tinnitus aurium. Examination showed dull thickened poorly mobile tympanic membranes. E.N.T. examination was otherwise negative. Audiometric examination showed a mixed type of hearing loss. The mastoid processes were rather acellular on X-ray examination. The provisional diagnosis was of a middle ear adhesive process. Exploration of the left ear was performed on 29 September 1969. A tympanomeatal flap was raised via a Rosens incision. A large bony lamina was found deep to the tympanic membrane with a broad base posteriorly in the pyramidal area, extending anteriorly to the head of the malleus. Deep to the bony lamina was a cystic swelling which appeared to occupy the whole of the tympanic cavity. The bony lamina was removed by chisel and drill, bringing into view the cystic swelling and a plane of cleavage between the cyst and the mucosa of the tympanic cavity (Fig. 1). We attempted to free the cyst from the periphery towards the centre from all directions, but this manoeuvre proved difficult due to hypertrophy of the malleus head. Intact removal of the cyst was not possible as it was adherent to the medial wall of the middle ear, so piecemeal removal was performed using forceps. The tympanic cavity had a poorly vascularized pale mucosa. The long process of the incus was blunted, and the stapes was absent. Ossicular muscles were also absent as were both the oval and round windows. Below the body of the incus and in the hypotympanum were seen bleeding fringes of tissue which were at first taken to be the remnants of the cyst. Their appearance, however, led us to suspect that the facial nerve had been damaged, and on examination we observed that the patient had developed a facial paralysis. On further inspection of the cyst and fringes we noticed that facial nerve fibres had been involved by the cyst, and it appeared that the cystic lining was supplied by perineural vessels. The fallopian aqueduct could not be seen. Because the oval and round windows were absent there was no 1065
Dorin Hociota and Traian Ataman
Bony lamina
Cyst
FIG.
I.
possibility for surgical improvement of the conductive hearing loss, and therefore we resorted to repair of the facial nerve. On the medial wall of the tympanic cavity part of the facial nerve was seen to be looped over the promontory. Because of this large curvature the ends of the facial nerve could be joined by diverting the nerve from its looped course. The third portion of the facial nerve was partially freed by lifting the bony plate. The severed ends were joined and covered in an aponeurotic cuff. Five weeks after surgery the paralysis of the temporo-facial nerve subsided, but the paralysis of the cervico-facial portion was unchanged. Histopathological examination (Dr. Gh. Vrejoiu) of the cystic formation showed an oedematous nodule, with the structure of a seromucosal salivary gland, covered by respiratory-type stratified epithelium. Fragments of the bony lamina had a compact osseous structure, with a welloutlined Haversian system. It thus became clear that we were dealing with an unusual congenital malformation of the tympanic cavity: absence of oval and round windows, absence of part of the ossicular chain, and an associated salivary gland adenochoristoma. We have conducted a review of the relevant literature, and now wish to discuss our findings in the light of the cases reported by other authors. Taylor, Martin, Steffen and House (1961) have reported similar cases. They carried out a biopsy on surgical exploration, but, because of the risk to the facial nerve, did no other surgery and consequently no further 1066
A case of salivary gland choristoma of the middle ear details are available. Noguera and Haase (1964) found a distorted ankylotic stapes in conjunction with a salivary gland choristoma. They carried out mobilization of the stapes footplate, and, using polyethylene tube, performed a malleoplatinal columellization. Brown (1964) noted a small choristoma between the tympanum and the incus without other anomalies. Although the choristoma was extirpated, deafness persisted. Caplinger and Hora (1967) found an adenochoristoma associated with hemi-facial atrophy—a low placed auricle, incudomalleal fusion, hypoplasia of the long process on the incus, absent stapes and oval window, and they suspected an anomaly of the course of the facial nerve because the site of emergence of the chorda-tympani could not be detected. Bruner (1970) gave a very clear cut description of a case of adenochoristoma, supplied by a stapedial artery, attached to the facial nerve deep to the body of the incus with a flat stapes, absent tensor tympani and a dehiscent slightly looped facial nerve. In our case a salivary gland choristoma occupied almost the whole of the tympanic cavity. There was an anomaly in the facial nerve course, the nerve making a loop as it crossed the promontory in a groove located anteriorly to the place where the windows should have been. The second part of the facial nerve canal, some of the third part, and the second elbow of the canal were absent. This kind of anomaly has been noted in the literature on two previous occasions only: firstly by Fowler (1961) with an associated microtia and, secondly, by Dickenson et al. (1968); in this case a normal aqueduct was present but this was occupied by fibrous tissue. The absence of oval and round windows has been encountered very seldom, but it has been noted by Ombredanne et al. (1971). Our case showed a subtympanic bone lamina in the area of the pyramid. Also the stapes and ossicular muscles were absent and there was hypoplasia of the long process of the incus. The association of these abnormalities is unique and possibly represents a syndrome. The relationship between the adenochoristoma and the other abnormalities in the tympanic cavity is in our view rather unclear. How is it possible for an element derived from the epiblast of the stomodeum (salivary gland choristoma) to arrive in the dorsal portion of the first branchial cleft? It seems that the phenomenon may have been caused by an aberrant parotid bud. Perhaps its presence in the tympanic cavity in, say, the third month of intra-uterine life induced the other abnormalities. However it is also possible that all the abnormalities developed at the same time. This case supports the hypothesis that the lateral wall of the tympanic portion of the fallopian aqueduct has a branchial origin. Therefore in the antefenestram course there is aplasia of the tympanic segment of the aqueduct and the lack of coalescence between the elements developed from the otic capsule and Reichert's branchial cartilage (Durcan, 1967).
Dorin Hociota and Traian Ataman In spite of a conductive hearing loss of 30-35 dB. throughout his life, the patient did not present until his cochlear threshold was affected by the onset of presbyacusis. We feel that an air /bone gap of such a degree is difficult to explain physiologically in the light of the abnormalities found in the middle ear (absence of windows and part of ossicular chain). It should be noted that the presence of tinnitus aurium is very seldom encountered in congenital phenomena. In our opinion this case is the most complete illustration to date of a salivary gland choristoma of the tympanic cavity associated with anomalies in the course of the facial nerve and the tympanic cavity contents. Summary The authors present a case of tympanic cavity salivary gland adenochoristoma in association with an abnormal course of the facial nerve, absence of the oval and round windows, absence of the stapes, hypoplasia of the long process of the incus, and the existence of a subtympanic bony lamina. Acknowledgements Assistance in the preparation of the manuscript was given by Mr. T. Heyworth and Dr. R. J. Bench, Royal Berkshire Hospital, Reading. REFERENCES BROWN, A. K. (1967) In: Caplinger and Hora. BRUNER, R. C. (1970) Archives of Otolaryngology, 3, 303. CAPLINGER, C. B., and HORA, J. F. (1967) Archives of Otolaryngology, 4, 365. DICKINSON, J. T., SRISOMBOON, F., and KAMERER, D. B. (1968) Archives of Oto-
laryngology, 4, 357. DURCAN, J. (1967) Archives of Otolaryngology, 86, 619. FOWLER, E. P. (1961) Laryngoscope, 8, 934. HOCIOTA, D., and ATAMAN, T. (1970) Comunicare la USSM, Sectia O.R.L.— Bucharest. Medical Centre of Phono-Audiology 30 Gh. Dinica. Street Sector VI Bucharest Roumania
1068
Dorin Hociota and Traian Ataman
Bony lamina
Cyst
FIG.
I.
possibility for surgical improvement of the conductive hearing loss, and therefore we resorted to repair of the facial nerve. On the medial wall of the tympanic cavity part of the facial nerve was seen to be looped over the promontory. Because of this large curvature the ends of the facial nerve could be joined by diverting the nerve from its looped course. The third portion of the facial nerve was partially freed by lifting the bony plate. The severed ends were joined and covered in an aponeurotic cuff. Five weeks after surgery the paralysis of the temporo-facial nerve subsided, but the paralysis of the cervico-facial portion was unchanged. Histopathological examination (Dr. Gh. Vrejoiu) of the cystic formation showed an oedematous nodule, with the structure of a seromucosal salivary gland, covered by respiratory-type stratified epithelium. Fragments of the bony lamina had a compact osseous structure, with a welloutlined Haversian system. It thus became clear that we were dealing with an unusual congenital malformation of the tympanic cavity: absence of oval and round windows, absence of part of the ossicular chain, and an associated salivary gland adenochoristoma. We have conducted a review of the relevant literature, and now wish to discuss our findings in the light of the cases reported by other authors. Taylor, Martin, Steffen and House (1961) have reported similar cases. They carried out a biopsy on surgical exploration, but, because of the risk to the facial nerve, did no other surgery and consequently no further 1066
A case of salivary gland choristoma of the middle ear details are available. Noguera and Haase (1964) found a distorted ankylotic stapes in conjunction with a salivary gland choristoma. They carried out mobilization of the stapes footplate, and, using polyethylene tube, performed a malleoplatinal columellization. Brown (1964) noted a small choristoma between the tympanum and the incus without other anomalies. Although the choristoma was extirpated, deafness persisted. Caplinger and Hora (1967) found an adenochoristoma associated with hemi-facial atrophy—a low placed auricle, incudomalleal fusion, hypoplasia of the long process on the incus, absent stapes and oval window, and they suspected an anomaly of the course of the facial nerve because the site of emergence of the chorda-tympani could not be detected. Bruner (1970) gave a very clear cut description of a case of adenochoristoma, supplied by a stapedial artery, attached to the facial nerve deep to the body of the incus with a flat stapes, absent tensor tympani and a dehiscent slightly looped facial nerve. In our case a salivary gland choristoma occupied almost the whole of the tympanic cavity. There was an anomaly in the facial nerve course, the nerve making a loop as it crossed the promontory in a groove located anteriorly to the place where the windows should have been. The second part of the facial nerve canal, some of the third part, and the second elbow of the canal were absent. This kind of anomaly has been noted in the literature on two previous occasions only: firstly by Fowler (1961) with an associated microtia and, secondly, by Dickenson et al. (1968); in this case a normal aqueduct was present but this was occupied by fibrous tissue. The absence of oval and round windows has been encountered very seldom, but it has been noted by Ombredanne et al. (1971). Our case showed a subtympanic bone lamina in the area of the pyramid. Also the stapes and ossicular muscles were absent and there was hypoplasia of the long process of the incus. The association of these abnormalities is unique and possibly represents a syndrome. The relationship between the adenochoristoma and the other abnormalities in the tympanic cavity is in our view rather unclear. How is it possible for an element derived from the epiblast of the stomodeum (salivary gland choristoma) to arrive in the dorsal portion of the first branchial cleft? It seems that the phenomenon may have been caused by an aberrant parotid bud. Perhaps its presence in the tympanic cavity in, say, the third month of intra-uterine life induced the other abnormalities. However it is also possible that all the abnormalities developed at the same time. This case supports the hypothesis that the lateral wall of the tympanic portion of the fallopian aqueduct has a branchial origin. Therefore in the antefenestram course there is aplasia of the tympanic segment of the aqueduct and the lack of coalescence between the elements developed from the otic capsule and Reichert's branchial cartilage (Durcan, 1967).
Dorin Hociota and Traian Ataman In spite of a conductive hearing loss of 30-35 dB. throughout his life, the patient did not present until his cochlear threshold was affected by the onset of presbyacusis. We feel that an air /bone gap of such a degree is difficult to explain physiologically in the light of the abnormalities found in the middle ear (absence of windows and part of ossicular chain). It should be noted that the presence of tinnitus aurium is very seldom encountered in congenital phenomena. In our opinion this case is the most complete illustration to date of a salivary gland choristoma of the tympanic cavity associated with anomalies in the course of the facial nerve and the tympanic cavity contents. Summary The authors present a case of tympanic cavity salivary gland adenochoristoma in association with an abnormal course of the facial nerve, absence of the oval and round windows, absence of the stapes, hypoplasia of the long process of the incus, and the existence of a subtympanic bony lamina. Acknowledgements Assistance in the preparation of the manuscript was given by Mr. T. Heyworth and Dr. R. J. Bench, Royal Berkshire Hospital, Reading. REFERENCES BROWN, A. K. (1967) In: Caplinger and Hora. BRUNER, R. C. (1970) Archives of Otolaryngology, 3, 303. CAPLINGER, C. B., and HORA, J. F. (1967) Archives of Otolaryngology, 4, 365. DICKINSON, J. T., SRISOMBOON, F., and KAMERER, D. B. (1968) Archives of Oto-
laryngology, 4, 357. DURCAN, J. (1967) Archives of Otolaryngology, 86, 619. FOWLER, E. P. (1961) Laryngoscope, 8, 934. HOCIOTA, D., and ATAMAN, T. (1970) Comunicare la USSM, Sectia O.R.L.— Bucharest. Medical Centre of Phono-Audiology 30 Gh. Dinica. Street Sector VI Bucharest Roumania
1068
