Learning objectives
To broaden the differentials of benign histiocytic disorders by reviewing their main primary and secondary causes in diagnostic imaging,
focusing the chest findings.
Background
The prototype of the primary histiocytic disorders is Langerhans cell histiocytosis.
Despite being the most common amongst them,
it is mandatory to know its variants along with some other important primary conditions.
The etiology of this group remains unknown and involves antigen-presenting cells and mediators of host immune system.
Secondary causes occur as a histiocytic response to an insult,
affecting the lung alone or associated with a wider systemic process.
This second group of disorders is further classified whether histiocytic response plays a major role...
Findings and procedure details
We have gathered special cases from our institution to illustrate the spectrum of the main primary and secondary histiocytic disorders affecting the lungs,
reviewing these diseases and their natural history,
with emphasis on the radiological findings.
Malignant conditions will not be addressed in this study.
1.
Primary Histiocytosis
1.1 Langerhans Cell Histiocytosis
Langerhans cell histiocytosis (LCH) is the most common disorder in the dendritic cell group.
However,
it is still a rare disease and it is characterized by proliferation and infiltration of Langerhans cells in...
Conclusion
The diseases displayed here are fairly rare,
making their diagnosis quite challenging,
since they usually do not come forth as our key differentials.
Knowing the imaging spectrum of histiocytic disorders is imperative,
especially for cardiothoracic radiologists,
in order to better assist the semiotics of such a challenging set of diseases,
resulting in an even earlier diagnosis and,
therefore,
a more favorable outcome.
References
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N.L.
Muller,
C.I.S.
Silva.
Imaging of the Chest.
Expert Radiology Series.
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2008;
2.Ahuja et al.
Histiocytic Disorders of the Chest: Imaging Findings.
RadioGraphics 2015; 35:357–370;
3.
Zaveri et al.
More than Just Langerhans Cell Histiocytosis: A Radiologic Review of Histiocytic Disorders.
RadioGraphics 2014; 34:2008–2024;
4.
D.
Vargas et al.
Cardiothoracic Manifestations of Primary Histiocytoses.
Br J Radiol.
2016 Dec;89(1068);
5.
S.S.
Siegelman.
Taking the X out of Histiocytosis X. Radiology 1997; 204 (2): 322 - 324;
6.
C.
Antunes,
B.
Graça,
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Donato....