Prognostic indicators for sensorineural hearing loss in temporal bone histiocytosis.

OBJECTIVE: Our review aims: (1) to highlight the suspicion of sensorineural hearing loss (SNHL) in temporal bone Langerhans' cell histiocytosis (LCH); (2) to assess the evolution of SNHL in this pathology; (3) to identify radiologic findings of the otic capsule invasion by LCH; (4) to determine prognostic factors for SNHL in temporal bone LCH. METHODS: We performed a literature review through MEDLINE for SNHL in temporal bone LCH related articles that were published between 1954 and 2008. We identified 12 related studies of which 18 patients were noted. We also added our case to this series. The information from the reports was analyzed to characterize the clinical and demographic data and to focus on the sensorineural hearing aspect of the disease and on the damage of the semicircular canals (SCC) and the cochlea. RESULTS: Ten percent of patients with temporal bone LCH presented SNHL. The mean age of patients is 3.5 years among children and 35.5 years among adults. Male to female ratio is 1:1.14. There were 13 unilateral cases, 6 bilateral cases and 1 case of multisystemic histiocytosis. Cochlea and SSCs were involved in 4 and 20 temporal bones, respectively. The lateral SCC is the most frequently eroded canal. In 23 ears hearing level was reported: 15 ears had a SNHL and the remaining was a mixed or a conductive hearing loss type. 10 ears suffered from a profound hearing loss and none of them improved after treatment regardless otic capsule affected structures. In all cases of normal hearing, moderate hearing loss and severe hearing loss before treatment cochlea have not been affected. However a single or two semicircular canals invasions have been noted. Where it is reported (15 out of 25 temporal bone) there was a radiological healing of the otic capsule lesion after treatment. Remineralization occurs 6 months after treatment. CONCLUSION: In LCH, hearing loss level before treatment can be considered as a prognostic indicator for hearing in response to treatment. Even though bone mineralization is essential for a hearing improvement, radiological healing is not a prognostic factor for better hearing level after treatment.

Langerhans' cell histiocytosis of the temporal bone in children.

OBJECTIVE: Langerhans' cell histiocytosis (LCH) is a rare pathology that implies an abnormal proliferation of these kinds of cells associated with a granular infiltration that affects different structures of the human body, including the temporal bone. The authors present their series of LCH of the temporal bone in children at the Sainte-Justine university hospital. The twofold objective of this study is to illustrate the clinical presentation, management and prognosis of this disease, and to compare these results with previously reported series. METHODS: A retrospective study was conducted between 1984 and 2007 with patients diagnosed and treated for a LCH of the temporal bone at the Sainte-Justine university hospital, a paediatric tertiary care center. A chart review was performed to obtain demographic, clinical, paraclinical, and therapeutic data. They were analysed and compared to other published series. Through a MEDLINE query, we found that since 1966, 50 articles dealing with a LCH of the temporal bone have been published. RESULTS: Fifty-nine cases of LCH were diagnosed and among them, 10 children had temporal bone involvement. They were four females and six males with a mean age of 3.28 years. The two most frequent clinical manifestations were the presence of a mass in the temporal region (70%) and otitis (60%). Two of our patients had a unifocal lesion of the temporal bone implicated. Eight patients had a multisystem involvement among which, two showed evidence of organ dysfunction. In 80% of cases, the diagnosis was made by immunohistochemical findings of the S-100 protein and/or the CD1 antigen. The common radiological finding on a skull CT scan is a lytic lesion in the temporal bone. Seven patients were treated by chemotherapy, two were treated by radiotherapy as a primary treatment, and one received radiotherapy for a recurrence on the pituitary gland. Finally, one patient was treated with local steroid injections. Two patients had a recurrence. All our patients were in total remission on a mean average of 1.6 years after the diagnosis. Our results concord with other studies in which the prognosis of unifocal bone disease is excellent and children with a multifocal disease have a survival rate of 65-100%. CONCLUSION: LCH is a rare disease. A high-index suspicion should be raised in the context of a temporal mass, chronic otitis, and otorrhea. A biopsy is recommended in the presence of a temporal bone lytic lesion. Chemotherapy is the preferred therapeutic modality.