Published online by Cambridge University Press: 27 August 2009
Introduction
Langerhans cell (LC) disease covers a wide range of clinical presentations with peaks of incidence in early and later life. What ties these disparate conditions together is their histopathology, which has as its bedrock the identification, in the tissues or fluids, of a population of abnormal Langerhans cell histiocytosis cells (LCH cells). Like all other laboratory tests, biopsy pathology must be subjected to the rules of sensitivity and specificity. Sensitivity relates to the incidence of false negative samples. Sampling is always an issue in biopsy pathology, but considerations of sensitivity relate to those features that are essential to the diagnosis so that ideally, all patients with LCH will be identified. Specificity in a diagnostic biopsy is concerned with false positive results, and deals with the differential diagnosis of those conditions most likely to be mistaken for LCH. Since LCH involves a multitude of different anatomical sites, each of which has unique issues of access, intrinsic anatomy and cell populations, as well as the other lesions characteristic to that site, the sensitivity and specificity of LCH diagnosis must be considered for each site.
The diagnostic criteria for LCH have been a moving target. Birbeck and colleagues first described intracytoplasmic inclusions in dermal LCs (Birbeck et al., 1961). Soon after Birbeck granules were found in histiocytosis X (Basset and Nezelof, 1966), tying histiocytosis X and dermal LCs together (Nezelof et al., 1973). Later CD1a was identified as a useful diagnostic marker for LCs and later for histiocytosis X (Murphy et al., 1983).
To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.