Temporal Bone Langerhans Cell Histiocytosis Presenting as Isolated Ataxia in a Pediatric Patient: Case Report and Literature Review

Langerhans cell histiocytosis (LCH) is a rare hematopoietic disorder characterized by granuloma formation in various body systems, with a corresponding variety of presenting symptoms. Head and neck disease accounts for ~60% of pediatric LCH, with temporal bone involvement in 4–16% of cases. Pediatric temporal bone LCH typically presents with a temporal bone mass, otorrhea, and hearing loss. Vestibular symptoms are very rare at presentation and are more often related to central nervous system (CNS) extension or treatment effects. We present a case of isolated ataxia as the presenting symptom for a pediatric patient with temporal bone LCH.

We present a 22-month-old girl who presented with new onset of falling and difficulty walking. Imaging with computed tomography (CT) and magnetic resonance imaging (MRI) showed a strongly contrast enhancing mass lesion within the right petrous bone with soft tissue obliteration of the middle ear cavity and mastoidal air cells with concomitant osseous destruction of the tegmen tympani, posterior contour of the petrous bone as well as dehiscence of the osseous coverage of the superior semicircular canal ([Figs. 1], [2], and [3]). Hearing was normal at the time of presentation. A mastoidectomy and biopsy of the mass confirmed the diagnosis of LCH with S100 and CD1a antigen positivity. Specimen genetic testing was positive for BRAF V600E mutation. Positron emission tomography showed involvement of the liver, spleen, and lymph nodes. She was treated with cytarabine chemotherapy with complete resolution of her ataxia symptoms. CT after treatment showed normalized aeration of the middle ear and mastoidal air cells including remineralization of the tegmen tympani, posterior contour of the petrous bone and osseous coverage of the superior semicircular canal.

Pediatric otolaryngologists should maintain a high index of suspicion for a temporal bone lesion in the setting of new onset ataxia, even in the absence of a palpable temporal bone mass and otorrhea. The radiological aspects of this case are of particular interest, as the lytic bone lesions typical for LCH resulted in erosion of the temporal bone tegmen, posterior cortex, and portions of the superior and posterior semicircular canals, resulting in opacification of the mastoid air cells and middle ear. Given that the patient presented with ataxia and did not exhibit any nystagmus, indicating a central rather than a peripheral source of ataxia, the patient's presenting symptoms may have been related more to cerebellar issues, either from mass effect or direct LCH cerebellar involvement. The fact that this patient has had LCH extension into the temporal bone puts her at greater risk of additional CNS manifestations. This patient did not present with diabetes insipidus (DI), a common CNS symptom of LCH, but development of DI in pediatric patients has been found to be associated with neurogenerative sequelae, resulting in increased disability and the need for intensive life-long medical management. Increased length of chemotherapy has been shown to reduce risk of DI in these patients, and this should be taken into consideration when planning the chemotherapy regimens for pediatric patients.

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
15 February 2022