Langerhans’ cell histiocytosis of the temporal bone in children

Summary

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.

Introduction

Langerhans’ cell histiocytosis (LCH) refers to a group of diseases whose primary pathogenesis is an abnormal polyclonal proliferation of Langerhans cells [1]. Langerhans cells, which are macrophages that are normally present only in the dermis, are the hallmark of this disease [2]. It is a disease that possesses three overlapping states called eosinophilic granuloma (EG), Hand–Schuller–Christian disease (HSC), and Letterer–Siwe (LS) disease [3].

The incidence of LCH is around 5.4 per million. It is a rare entity with a male predominance [2]. Its peak incidence period is noted in children aged between 1 and 4 years, but it can affect patients of any age [1], [4].

The clinical presentation of LCH depends upon the site of involvement. It can range from a multi-focal to a solitary lesion. It usually affects the head and neck, mainly the skull base, in 60% of cases [3], [4]. The temporal bone is involved in 19–25% of cases and the involvement is bilateral in a third of all cases [2], [5]. The petrous ridge of the temporal bone is the most commonly affected area [5].

The LCH has an unpredictable natural history varying from a rapidly, fatal, progressive disease to spontaneous resolution [2]. However, the usual prognosis of the disease affecting the temporal bone is good in patients having limited organ involvement, with a survival rate of over 90% [1]. Age at presentation, multisystem involvement and vital organ dysfunction are the most relevant prognostic factors [2]. The outcome is worse in children younger than 2 years old.

The aim of this article is to present demographic data, with a review of the clinical presentation, work-up, treatment, and outcome of all paediatric patients diagnosed with a temporal bone LCH at the tertiary university medical center, Sainte-Justine hospital, over the last 23 years and also, to compare our results with those published in the literature.