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Keywords
Blastomycosis, EUS, mediastinal mass
Introduction
Endosonographic evaluation of the mediastinum
has developed rapidly. EUS is particularly well suited to
determine the etiology of masses identified in the posterior
mediastinum. The following case report is an unusual presentation
of pulmonary Blastomycosis diagnosed by EUS-FNA.
Methods for EUS Capture
EUS was performed with the linear array
Pentax FG36UX.
Case/Body
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Figure 1A
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Figure 1B
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Figure 2
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Figure 3
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A 46-year-old woman from northern Wisconsin
presented with a non-productive cough and right posterior
chest pain. She was initially seen by her primary care provider
and was treated for bronchitis with antibiotics. Her symptoms
did not improve. She denied weight loss. She denied hemoptysis.
She had no upper gastrointestinal symptoms.
Her past medical history was notable for diabetes mellitus
and hypothyroidism. Her past surgical history included a cholecystectomy
and an appendectomy.
Her social history was significant in that she smoked two
packs of cigarettes per day. Her current medications included
synthroid, glucotrol, and insulin.
Her physical exam was unremarkable. There was no peripheral
adenopathy. Her lung exam was normal.
A chest x-ray showed a possible right hilar mass. A CT scan
of the chest demonstrated a 3.2 cm by 2.7 cm right hilar mass.
No parenchymal lesion was identified.
She underwent a bronchoscopy which was normal. Boncho-aveolar
lavage was negative, and EUS was requested to further evaluate
and obtain cytology.
In the mid-esophageal position imaging in the right hilum,
an irregular mass with inhomogeneous echo characteristics
was identified (Figure 1A). A representative Visible Human
image from the same approximate location is shown in Figure
1B, in which the esophagus is in the center, with the aorta
below, and the right mainstem bronchus above.
Wilson-Cook 22 gauge FNA was used to collect material for
both cytology and cell block preparations. The cytology demonstrated
histiocyte clusters consistent with a granuloma (Figure 2).
The cell block showed dimorphic budding yeasts consistent
with blastomycosis (Figure 3). No culture was done given the
clinical presentation, and the highly supportive cytologic
findings. The patient was treated with 6 months of Itraconazole
200 mg p.o. b.i.d. with a good clinical response. A follow-up
chest x-ray at 8 weeks showed improvement radiographically.
Discussion/Summary Statement
EUS has gained popularity in evaluating
mediastinal masses. Panelli et al. retrospectively reviewed
their experience with EUS and EUS guided FNA of posterior
mediastinal masses and concluded that this modality is an
effective means to evaluate the mediastinum (1). A variety
of indications for mediastinal sampling exist. The most common
being preoperative evaluation of patients with known or suspected
lung cancer. Non-malignant diagnoses can be made at EUS and
include reactive lymphadenopathy (often in a smoker), sarcoidosis,
and infections involving the mediastinum. This appears to
be the first reported case of Blastomycosis being diagnosed
by EUS-FNA.
Blastomycosis is a fungal infection caused by a thermal dimorphic
fungus. Most cases in the United States are reported to occur
in the Great Lakes region and the southeastern portion of
the United States. A large outbreak was reported in Wisconsin
with isolation of Blastomyces Dermatitidis in the soil at
a beaver dam (2). Pulmonary manifestations are the most common
clinical presentation of Blastomycosis. The skin, bones, and
genitourinary systems are the most frequent extrapulmonary
systems involved with this entity (3).
Treatment options for Blastomycosis include Itraconazole (mild
to moderate disease) and Amphotericin B (life-threatening
disease). Treatment duration varies from 6 months to 1 year
(3).
This case represents an unusual example of a right hilar mass
secondary to Blastomycosis, responsive to anti-fungal treatment,
diagnosed by EUS-FNA.
This case also illustrates the importance of performing cell
block preparations at EUS-FNA as additional information can
be obtained with this technique.
References
1. Panelli F, Erickson RA, Prasad VM. Evaluation
of mediastinal masses by endoscopic ultrasound and endoscopic
ultrasound-guided fine needle aspiration. AJG
2001;96:401-8.
2. Klein BS, Vergeront JM, Weeks RJ et al.
Isolation of Blastomyces dermatitidis in soils associated
with a large outbreak of blastomycosis in Wisconsin.
NEJM 1986;314:529-34.
3. Chapman SW, Bradsher Jr., RW, Campbell
DG et al. Practice Guidelines for the Management of Patients
with Blastomycosis. Clinical Infectious Diseases
2000;30:679-83.
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