Langerhans' cell histiocytosis of the temporal bone and skull base

Abstract

A 22-month-old boy was referred for evaluation of a slowly enlarging right postauricular mass. The mass was first noticed by his mother 3 weeks earlier, shortly after the patient was diagnosed with a right otitis media. The patient was on a second course of antibiotics for this episode of otitis, which had been his third or fourth episode in the previous 12 months. The child had otherwise been well and was afebrile. There was no report of otorrhea or drainage from the mass. The patient stayed with a babysitter during the day, and a few declawed cats were in the household. There was no history of prior ear surgery or exposure to tuberculosis. Physical examination revealed a healthyappearing child in no apparent distress. Cerumen filled the right ear canal, which when removed revealed a retracted eardrum with a middle ear effusion. The left tympanic membrane was normal. The right postauricular mass measured approximately 3 3 cm, was soft, and was mildly tender. Additionally, the skin overlying the mass was slightly erythematous. The remainder of the head and neck exam was completely normal aside from nontender right cervical adenopathy. A computed tomography scan of the soft tissues of the temporal bones and neck with contrast was obtained and revealed a mass 2 2 3.5 cm in the right mastoid (Fig 1). The mass extended through the tegmen into the posterior cranial fossa, elevating of the overlying dura and further extending laterally through the temporal bone into the postauricular soft tissues. The mass also appeared to be eroding the lateral wall of the posterior semicircular canal. Complete opacification of the mastoid air cells and the middle ear space was seen; however, the ossicular chain appeared intact (Fig 2). A second mass was noted within the right infratemporal fossa with the epicenter located about the pterygoid muscles and measured approximately 2 2 4 cm. The mass extended into the nasopharynx where it obliterated the fossa of Rosenmuller. It also extended anteriorly into the pterygoid plates and abutted the right maxillary sinus lateral wall. Multiple deep and superficial cervical chain lymph nodes, the largest of which measured 1.5 2.5 cm in diameter, were at the level of the carotid bifurcation in the right neck. The possible diagnoses included Langerhans’ cell histiocytosis (LCH), rhabdomyosarcoma, metastatic neuroblastoma, and, less likely, multiple myeloma. The patient was taken to the operating room for incisional biopsy of the right postauricular mass. In addition, hematology and oncology departments were consulted to carry out a bone marrow biopsy, since the possibility of rhabdomyosarcoma was raised. At surgery, a postauricular incision was made and flaps were raised over a well-encapsulated lesion that protruded through a cortical mastoid defect. The mass was transected completely at the level of the bony cortex, revealing a light brown material that appeared semi-necrotic and with the consistency of fat. No purulent fluid was found. A myringotomy was also carried out and revealed dirty brown fluid in the middle ear space. A tympanostomy tube was placed. Slides of the biopsy tissue stained with hematoxylin-eosin demonstrated a connective tissue matrix containing masses of histocytic cells and numerous eosinophils (Fig 3). The histiocytes had irregular nuclear contours and From the Department of Otolaryngology–Head and Neck Surgery, Eastern Virginia Medical School, Norfolk, VA. Address reprint requests to Craig S. Derkay, MD, Department of Otolaryngology–Head and Neck Surgery, 825 Fairfax Avenue, Suite 510, Norfolk, VA 23507 Copyright 2002,ElsevierScience (USA).All rights reserved. 0196-0709/02/2304-0001$35.00/0 doi:10.1053/ajot.2002.123452