Eosinophilic Granulomatous Disease (histiocytosis X)
Siavash K Kurdistani, MD candidate
Attending????
Presentation
A 16-year-old woman
with a 4-year history of smoking presented with a
a cough producing yellow-brown
sputum. The cough had persisted for 2 months.
Imaging Findings
PA chest radiograph
Chest CT
A posteroanterior (PA) chest radiograph demonstrates a moderate
pneumothorax on the left and a diffuse and bilateral
coarse reticulonodular interstitial pattern
mostly in mid-upper lung zones with cystic
changes. The costophrenic angles were
relatively sparred.
Computed tomograph (CT) of the chest confirmed the moderate pneumothorax on the left
and revealed innumerable bilateral cystic
lesions, predominantly in the middle and
upper lungs. The cysts were characterized
by thin walls and irregular margins. No
lymphadenopathy was noted.
Differential Diagnosis
Infections such as TB and histo should be
considered. Sarcoid (reticular opacities
with marked peribronchial thickening) and
pneumoconiosis are also included. Stage 4
sarcoidosis may produce similar cystic
lesions. Lymphangiomyomatosis (cysts with
thin walls and mostly in bases), idiopathic
pulmonary fibrosis (cystic or honeycomb
pattern distinctly peripheral and usually
basal), tuberous sclerosis and Wegner’s
should be considered. Cystic fibrosis causes
bronchiectasis. The following features are
particularly suggestive of pulmonary
histiocytosis X: minimal sx, relatively
normal pulmonary fx, radiographic
abnormalities, absence of hilar adenopathy,
PTX, predominantly upper lobe involvement,
diabetes insipidus, bone lesions.
Diagnosis
eosinophilic granulomatous disease (histiocytosis X)
Discussion
Histiocytosis X refers to a group of disorders
characterized by proliferation of a special
type of histiocytes called the Langerhans
cells, a member of the mononuclear
phagocytic system that is most commonly
found in the skin. These are reactive disorders
in which the non-neoplastic proliferation of
the Langerhans cells results from
disturbances in immunoregulation. The
members of histiocytosis X family are
Hand-Schüller-Christian disease, which is
characterized by the triad of membranous
bone defects; exophthalmous and diabetes
insipidus; and Letterer-Siwe disease, a
rapidly progressive and fatal multisystem
disease of infants and children; and
eosinophilic granuloma (EG) of the lung.
The term “eosinophilic granuloma” is a
misnomer, since the disorder is neither
truly granulomatous nor characterized
principally by eosinophils in the infiltrate.
Histologically, the cellular infiltrate is
interstitial and consists of a mixed population
of inflammatory cells including a variable
number of eosinophils, plasma cells, and
lymphocytes. The diagnostic cell is not
eosinophil, rather the Langerhans cell
(histicytosis-X cell). The infiltrate often has
a nodular appearance in early disease,
whereas more advanced disease is
characterized by extensive fibrosis and
prominent cyst formation. The radiographic
distribution is notable for an upper zone
predominance, and the pattern changes from
nodular to reticulonodular to cystic. This
corresponds to the evolutionary sequence of
pulmonary lesions: nodules, cavitated nodules,
thick-walled cysts, thin-walled cysts. Unlike
most of the other interstitial lung diseases,
EG is often associated with perservation of
lung volumes, presumably because of the
extensive cyst formation. EG most commonly
affects young and middle aged caucasians
(20-40) most of whom (>90%) are current
or past cigarette smokers. Many patients are
asymptomatic and are diagnosed incidentally.
A pneumothorax is seen in 14% of the
patients. In about half of cases, the outcome
is favorable with or without treatment;
respiratory symptoms disappear and CXR
normalizes. In 1/3, the disease is stable. In
20%, the disease progresses rapidly with
more cystic changes, airflow obstruction,
impairment of diffusing capacity, and the
development of respiratory failure. PTX
complicates the course of the disease.
Pulmonary arterial HTN may result from
extensive parenchymal destruction or
vasculitis. Treatment of EG of the lung is, in
general, unsatisfactory and controversial and
has included steroids and cytotoxic drugs.
Cessation of smoking is known to induce
complete radiographic clearing in some cases.
Antibiotics are used for a concurrent
infection, and pleurodesis is performed for
repeated pneumothoracies.
References
BraunerMW, Grenier P, Tijani K,
Battesti JP, Valeyre D. Pulmonary
Langerhans Cell Histiocytosis: evolution of
lesions on CT scans. Radiology 1997;204:497-502.
Moore AD, Godwin JD, et al. Pulmonay
Histiocytosis X: comparison of radiographic
and CT findings. Radiology 1989;172:249-254.
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PA chest radiograph
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