TABLE IV.
Definition of Organ Involvement in Langerhans Cell Histiocytosis
| Criteria | CNS risk lesions | Risk organ |
|---|---|---|
| Bone involvement | ||
| General bone involvement: all radiologically documented lesions, which are not mentioned below | ||
| Craniofacial bone involvement: lesions in the orbital, temporal, mastoid, sphenoidal, zygomatic, or ethmoidal bones; the maxilla or paranasal sinuses; or cranial fossa; with intracranial soft tissue extension | Yes | |
| Vertebral involvement without soft tissue extension, for example, vertebra plana | ||
| Vertebral involvement with intraspinal soft tissue extension or lesions in the odontoid peg | ||
| An abnormality on Tc bone scan or an MRI hypersignal, not correlated with symptoms, or with an X-ray image is not considered bony disease! | ||
| Central nervous system (CNS) involvement | Yes | |
| Tumoral: all intracerebral expansive lesions predominantly affecting the brain or meninges | ||
| Neurodegeneration on MRI: MRI imaging compatible with neurodegenerative diseasea, that is, abnormal signal intensity localized in the dentate nuclei or cerebellum or cerebral atrophy NOT explained by corticosteroids | ||
| Clinical neurodegeneration: presence of suggestive symptoms (either cerebellar syndrome or learning difficulty) with compatible MRI imaging | ||
| Ear involvement | ||
| Ear involvement with external otitis, otitis media, or otorrhea | Yes | |
| Eye involvement | ||
| Orbital involvement with proptosis or exophthalmos | Yes | |
| Hematopoietic involvement | Yes | |
| Mild (both of the following categories should be present) | ||
| Hemoglobin between 10 and 7 g/dl (not due to other causes, e.g., iron deficiency) | ||
| Thrombocytopenia with platelets between 100,000 and 20,000/mm3 | ||
| Severe (both of the following categories should be present) | ||
| Hemoglobin <7 g/dl (not due to other causes, e.g., iron deficiency) | ||
| Platelets <20,000/mm3 | ||
| Liver involvement (the patient can show a combination of these symptoms) | Yes | |
| Enlargement >3 cm below the costal margin at the mid clavicular line, confirmed by ultrasound or dysfunction documented by: hyperbilirubinemia >3 times normal hypoalbuminemia (<30 g/dl), γ GT increased >2 times normal, ALT (SGPT)–AST (SGOT) >3 times normal, ascites, edema, or intra hepatic nodular mass | ||
| Lung involvement | (Yes)b | |
| Typical imaging (nodules or cysts) on CT scan | ||
| Any atypical mass needs to be explored by BAL or biopsy in order to have histopathological/cytological diagnosis | ||
| Mucosa involvement | ||
| Oral involvement with lesions in the oral mucosa, gums | ||
| Genital or anal involvement | ||
| Pituitary involvement | ||
| Any pituitary hormone deficiency or tumor appearance in the hypothalamic-pituitary axis | ||
| Skin involvement | ||
| Any rash documented by histological examination or any lesion (erythematous and crusted macules, papules, or nodules, with or without ulceration, or petechiae, or seborrhea-like picture) compatible with the diagnosis, if LCH is confirmed by biopsy of another organ | ||
| Spleen involvement | Yes | |
| >3 cm below the costal margin at the mid clavicular line, confirmed by ultrasound | ||
ALT (SGPT), alanine transaminase (serum glutamic pyruvic transaminase); AST (SGOT), aspartate transaminase (serum glutamic oxaloacetic transaminase); BAL, bronchoalveolar lavage; CT, computed tomography; MRI, magnetic resonance imaging.
a
The term radiological neurodegeneration has been coined to describe a certain pattern of MRI findings, but this terminology may be misleading as it does not necessarily correlate with histopathology.
b
See section “Risk organs.”