Erdheim–Chester disease presenting with an intramedullary spinal cord lesion

Abstract

Erdheim–Chester disease (ECD) is a rare form of nonLangerhans histiocytosis characterized by multi-systemic xanthogranulomatous infiltration. The disease commonly affects the skeleton, but may also involve the skin, viscera including the cardiovascular system and lungs, as well as the central nervous system [1–4]. Diagnosis is based on histopathology typically showing infiltration by histiocytes expressing CD68, but not CD1a [3]. In the nervous system, ECD commonly affects the neurohypophysis resulting in diabetes insipidus. Extrahypophyseal nervous system involvement is seen in about a third of ECD patients and includes intra-axial infiltrative lesions, meningioma-like masses, and periarterial infiltration [3, 5, 6]. Spinal cord involvement may occur due to extramedullary masses [3, 7, 8] but intra-axial cord lesions are rare and only a single patient has been described [9]. We report a case of ECD presenting with progressive spastic paraparesis caused by an intramedullary cord tumor. A 31-year-old female was referred to our clinic with a 10-year history of slowly progressive gait difficulties due to a spinal cord mass. She also complained of polydipsia, polyuria, and irregular menstruation. Clinical examination revealed spastic paraparesis with extensor plantar responses and normal sensory function. There was saccadic smooth pursuit in all directions and horizontal nystagmus on lateral gaze, but no other signs of cerebellar dysfunction. She had multiple periorbital xanthelasma-like lesions (Fig. 1). She did not complain of skeletal pain. MRI of the brain revealed symmetrical high T2 signal in the cerebellar white matter, sparing the dentate nuclei. There was calcification of the dentates and globus pallidus (Fig. 1). MRI of the spine showed diffuse, non-contrast enhancing, low T1 and T2 signal changes in multiple cervical and thoracic vertebrae. There was a fusiform masslesion of the thoracic cord showing inhomogeneously high T2 signal intensity and partial contrast enhancement (Fig. 2). Scintigraphy with technetium 99 and fluorodeoxyglucose positron-emission tomography (FDG-PET) showed pathological tracer uptake in the epiphyses of long bones, several cervical and thoracic vertebra (corresponding to signal changes on the MRI) and parts of the facial skeleton. Skeleton radiograms showed moderate hyperostosis of the skull and sclerotic changes in the epiphyses of the long bones (Fig. 1). A computed tomography (CT)-guided biopsy of the 9th thoracic vertebra was performed. Histology revealed a hypercellular bone marrow with focal fibrosis and infiltration C. Tzoulis (&) I. O. Gjerde Department of Neurology, Haukeland University Hospital, 5021 Bergen, Norway e-mail: chtzoulis@yahoo.com; charalampos.tzoulis@helsebergen.no