AJR 2000; 174:799-801
© American Roentgen Ray Society
Psyllium Aspiration Causing Bronchiolitis
Radiographic, High-Resolution CT, and Pathologic Findings
Michele M. Janoski1,
Gregory S. Raymond1,
Lakshmi Puttagunta2,
Godfrey C. W. Man3 and
James R. Barrie1
1
Department of Radiology and Diagnostic Imaging, Division of Thoracic Imaging,
University of Alberta Hospital, 8440-112 St., Edmonton, Alberta, T6G 2B7
Canada
2
Department of Laboratory Medicine and Pathology, University of Alberta
Hospital, Edmonton, Alberta, T6G 2B7 Canada.
3
Department of Medicine, Division of Pulmonary Medicine, University of Alberta
Hospital, Edmonton, Alberta, T6G 2B7 Canada.
Received June 2, 1999;
accepted after revision August 9, 1999.
Address correspondence to J. R. Barrie.
Introduction
Aspiration pneumonia is characterized radiographically by the presence of
air-space consolidation involving mainly the perihilar and dependent regions
of the lung [1]. Aspiration of
leguminous vegetables is a more specific entity described as a granulomatous
bronchiolitis and referred to as lentil aspiration pneumonia. Lentil
aspiration pneumonia usually results in a reticulonodular interstitial pattern
radiographically and centrilobular nodular opacities on high-resolution CT
[2,3].
We describe a case of psyllium aspiration causing a granulomatous
bronchiolitis and foreign body reaction. Follow-up high-resolution CT revealed
localized areas of air trapping suggesting the development small airways
disease, possibly constrictive bronchiolitis.
Case Report
A previously healthy 48-year-old woman accidentally inhaled approximately 1
teaspoon of psyllium (Prodiem; Novartis Consumer Health Canada, Mississauga,
Ontario, Canada)—medication for chronic constipation. In a few days the
patient began experiencing constitutional symptoms and a nonproductive cough.
The patient subsequently developed progressive shortness of breath with
deterioration of pulmonary function tests showing approximately 20% reduction
in lung diffusion capacity and evidence of moderate airways obstruction. Chest
radiography revealed a bibasilar, predominantly nodular, interstitial
abnormality (Fig. 1A).
High-resolution CT and bronchoscopy were performed 9 days after the
aspiration event. High-resolution CT, using 1-mm collimation at 10-mm
increments, showed a profusion of small, well-defined centrilobular nodules
and branching linear opacities with an appearance resembling a tree in bud
(Fig. 1B). These findings were
present in the lower lobes and, to a lesser extent, the right middle lobe and
lingula. On bronchoscopy the visualized airways were normal. Transbronchial
biopsy, brush biopsy, and bronchoalveolar lavage of the right lung were
performed. All cultures were negative.
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Fig. 1B. —48-year-old woman who aspirated psyllium granules. Targeted
high-resolution CT scan at level of lower right hilum reveals centrilobular
pattern of well-defined nodules, several of which are arranged in
"tree-in-bud" pattern (arrow).
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Because of persistence of abnormal radiologic and pulmonary function
findings, a right thoracoscopic lung biopsy was performed 1 month after the
aspiration event. Biopsy specimens revealed a granulomatous inflammatory
process centered on small airways at the level of the terminal and respiratory
bronchioles (Figs. 1C and
1D). A few giant cells were
present that contained foreign material, positive for periodic acid-Schiff,
consistent with a cellulosic material such as psyllium. As a therapeutic
trial, the patient was treated with steroids and bronchodilators. The steroids
were eventually tapered off after 1 month because the patient experienced
improvement both in symptoms and in pulmonary function tests. A follow-up
high-resolution CT scan 14 months after the aspiration event revealed slight
improvement in the number of centrilobular nodules
(Fig. 1E). However, focal areas
of decreased attenuation and vascularity were present with evidence of air
trapping on expiratory CT, findings suggestive of small airways disease,
possibly constrictive bronchiolitis (Figs.
1F and
1G).
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Fig. 1C. —48-year-old woman who aspirated psyllium granules. Photomicrograph
shows pulmonary artery (curved arrow) and accompanying bronchiole
(short straight arrow) with partial obliteration of airway lumen by
granulomatous inflammation (long straight arrow). Granulomatous
inflammation is restricted to small airways without significant involvement of
alveoli. (H and E, x80)
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Fig. 1D. —48-year-old woman who aspirated psyllium granules. Photomicrograph
shows granulomatous inflammation. Note multiple foreign body-type
multinucleated giant cells. One giant cell contains foreign material within
cytoplasm (arrow). (H and E, x520)
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Fig. 1E. —48-year-old woman who aspirated psyllium granules. High-resolution
CT scan at level of pulmonary hilum obtained 14 months after aspiration of
psyllium granules shows slight decrease in profusion of centrilobular nodules.
Note that mosaic perfusion has developed in interval.
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Fig. 1F. —48-year-old woman who aspirated psyllium granules. Inspiratory
(F) and expiratory (G) CT scans at lung base show that, on
G, geographic areas of air trapping have developed. Air trapping is
consistent with moderately extensive small airways disease and possibly
constrictive bronchiolitis.
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Fig. 1G. —48-year-old woman who aspirated psylliun granules. Inspiratory
(F) and expiratory (G) CT scans at lung base show that, on
G, geographic areas of air trapping have developed. Air trapping is
consistent with moderately extensive small airways disease and possibly
constrictive bronchiolitis.
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Discussion
Psyllium, derived from the seeds of the fleawort plant, is a commonly used
dietary fiber supplement and bulk laxative. Prodiem is a psyllium preparation
consisting of lightbrown, minty-tasting 2- to 3-mm granules. To our knowledge,
aspiration of psyllium has not been specifically described in the literature.
The findings of centrilobular nodules and branching linear opacity seen in our
patient are similar to the findings of lentil aspiration pneumonia as
described by Marom et al. [2,
3]. Lentil aspiration pneumonia
produces a characteristic pattern of microabscess formation followed by the
development of granulomatous inflammation
[2]. The diagnosis is made with
the pathologic confirmation of cellulose material. Radiographically, small, 1-
to 3-mm nodular opacities are typically seen, although nodules as large as 1
cm in diameter have been observed
[2,
3]. On high-resolution CT,
lentil aspiration pneumonia manifests as centrilobular nodules, some with the
tree-in-bud configuration [2,
3]. In patients with these
findings the tree-in-bud pattern reflects the presence of bronchiolar
impaction with secretions.
Constrictive bronchiolitis is usually the result of prior infection, toxic
fume inhalation, a drug reaction associated with connective tissue diseases,
or a complication of lung and bone marrow transplantations
[4]. It is rarely idiopathic.
To our knowledge, the high-resolution CT findings of constrictive
bronchiolitis after aspiration have not been previously described. In our
patient, the follow-up high-resolution CT revealed mosaic perfusion
accentuated with expiration, a finding suggestive of moderately extensive
small airways disease, possibly constrictive bronchiolitis given the initial
histologic appearances and serial radiologic changes.
In summary, our patient developed a tree-in-bud pattern, caused by
aspiration of psyllium, which is indicative of small airways disease. Our case
emphasizes the potential for a foreign-body reaction caused by aspiration,
resulting in a granulomatous bronchiolitis.
References
-
Armstrong P, Wilson AG, Dee P, Hansell DM. Imaging of
diseases of the chest, 2nd ed. St. Louis: Mosby,
1995:453-454
-
Marom E, McAdams H, Sporn T, Goodman P. Lentil aspiration
pneumonia: radiographic and CT findings. J Comput Assist Tomogr
1998;22:598-600[Medline]
-
Marom E, McAdams H, Erasmus J, Goodman P. The many faces of
pulmonary aspiration. AJR
1999;172:121-128[Abstract/Free Full Text]
-
Webb R, Muller N, Naidich D. High resolution CT of the
lung, 2nd ed. Philadelphia: Lippincott Raven,
1996:258-265
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Introduction
Case Report
