Chest
Volume 132, Issue 5, November 2007, Pages 1579-1583
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Original Research
ORGANIZING PNEUMONIA
Focal Organizing Pneumonia on Surgical Lung Biopsy: Causes, Clinicoradiologic Features, and Outcomes

https://doi.org/10.1378/chest.07-1148Get rights and content

Background

Organizing pneumonia (OP) is a histologic pattern that is morphologically distinctive but nonspecific and can be seen in diverse clinical settings. Focal OP has been described as a discrete form of OP, but relatively little is known regarding this clinicopathologic entity.

Methods

We sought to clarify the clinicoradiologic presentation, underlying causes, and outcomes associated with focal OP by retrospectively reviewing 26 consecutive cases diagnosed by surgical lung biopsy over an 8-year period from January 1, 1997, to December 31, 2004.

Results

All patients presented with an unifocal opacity detected on chest radiography (20 patients) or CT scans (6 patients). At the time of presentation, 10 patients (38%) had symptoms, including cough, shortness of breath, or chest pain; 16 patients were asymptomatic. Contrast-enhancement CT scanning or positron emission tomography (PET) scan was performed in 11 patients, and the results were positive in all. Surgical procedures included wedge resection in 21 patients (81%), segmentectomy in 3 patients (11%), and lobectomy in 2 patients (8%). Three case of focal OP (12%) were related to infections, but the remaining cases were cryptogenic. Follow-up over a median interval of 11 months (range, 1 to 71 months) yielded no recurrence of OP.

Conclusions

The radiologic features of focal OP are often indistinguishable from those of lung cancer, and include positivity on contrast-enhancement CT scan and PET scan. Most cases of focal OP are cryptogenic, and infection is identified in a minority of cases. Surgical resection alone appears to suffice in the management of cryptogenic focal OP.

Section snippets

Materials and Methods

Patients with OP diagnosed by surgical lung biopsy at the Mayo Clinic in Rochester, MN, from January 1, 1997, to December 31, 2004, were identified by a computer-assisted search of medical records. There were 203 patients whose surgical lung biopsy specimens demonstrated OP; 26 patients (13%) presented with a unifocal lesion on chest imaging and were included in the study group. This study was approved by the Institutional Review Board of the Mayo Foundation.

Demographics and Clinical Presentation

The median age of the patients was 66 years (range, 36 to 86 years); 11 patients (42%) were women (Table 1). Seven patients were current smokers (27%). No other relevant exposure was elicited except for one patient who worked as a welder. Ten patients (38%) had symptoms, as listed on Table 1; the remaining 16 patients (62%) were asymptomatic. Twenty patients (77%) had no relevant findings on physical examination; the remaining 6 patients were noted to have bibasilar crackles or wheezes, which

Discussion

OP is a nonspecific histopathologic lesion and can be associated with various clinical contexts and radiologic patterns. In this study, we focused on OP presenting as a unifocal lesion on chest imaging (ie, focal OP), which accounted for 13% of cases of OP diagnosed from surgical lung biopsy specimens at our institution over an 8-year period. Other studies61617 have reported similar rates of focal OP among their case series of OP. The majority of our patients with focal OP were asymptomatic,

References (20)

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The authors have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

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