Evaluation of Cultures of Percutaneous Core Needle Biopsy Specimens in the Diagnosis of Pulmonary Nodules

Abstract

The value of cultures of tissue obtained by image-directed core needle biopsy of lung nodules has not been determined. Of the 250 biopsies performed during a 5-year period in an area endemic for coccidioidomycosis, 225 (90%) were diagnostic. Granulomas were identified in 75 specimens, whereas 3 specimens revealed abscess. Ziehl-Neelsen stain was positive for acid-fast bacilli (AFB) in 2 cases. Spherules of Coccidioides immitis were seen in 54 of the biopsy specimens with granulomas. Microbiologic cultures were positive for C immitis in 5 (9.6%) of 52 biopsy specimens.Image-guided percutaneous core needle biopsy (CNB) is being increasingly performed in the diagnosis and treatment of solitary and multiple pulmonary nodules. Fine-needle aspiration (FNA) biopsy, which yields material for cytologic evaluation, is an established method with high sensitivity and specificity in the diagnosis of malignancy 1 ; cytologic examination alone, however, may not be definitive in categorizing a benign disease process.2 Since the initial report on the efficacy of percutaneous CNB in the United States by Parker et al 3 in 1989, many radiologists have advocated the use of the automated biopsy gun to obtain tissue samples for definitive histologic diagnosis. [4][5][6] Because the main differential diagnosis of a localized pulmonary lesion is an infectious process or a neoplasm, a portion of the CNB tissue is usually submitted for microbiologic cultures in an attempt to isolate and identify the causative infectious agent. tion, 10 have been found valuable, the usefulness of culturing a CNB specimen has not been evaluated.This study was conducted to determine the relative sensitivities of cultures and special stains for microorganisms in histologic sections of CNB specimens of pulmonary nodules. MATERIALS AND METHODSBetween July 1990 and June 1995, 250 imagedirected percutaneous CNBs were performed in the radiology department of the Carondelet St Mary's Hospital in Tucson, Ariz, an area endemic for coccidioidomycosis. A 20-gauge spring-loaded automated biopsy gun (Monopty; Bard, Covington, Ga) was used to obtain specimens for histologic evaluation. All biopsy procedures were performed by the coaxial technique, with initial localization accomplished by an 18-gauge thin-walled guiding needle. Fluoroscopic guidance was used in 237 procedures, and 13 were directed by computed tomography.The biopsy samples were collected and delivered in saline solution to the surgical pathology laboratory. A portion of the tissue was submitted to the microbiology laboratory for culturing; the remaining specimen was fixed in formalin and routinely processed. During sectioning, two slides containing contiguous ribbon of tissue were prepared at each level. One of the slides, representing one level of sectioning, was stained with hematoxylin-eosin,

Recent Advances in Our Understanding of the Environmental, Epidemiological, Immunological, and Clinical Dimensions of Coccidioidomycosis

“…As many as 30% of lung nodules biopsied in the area of endemicity are due to coccidioidomycosis (161). Histologic examination is more sensitive than culture for detection of coccidioidal lung nodules (162,163). Patients with asymptomatic lung nodules do not benefit from antifungal therapy (160).…”

Coccidioidomycosis pulmonary infection

“…Occasionally, a nodule may present a diagnostic dilemma, particularly when it occurs in persons who reside outside of endemic areas. In residents of endemic areas with solitary pulmonary nodules, between 33% and 51% may be due to cancer [14,15]. Because the radiographic appearance of coccidioidal nodules is frequently indistinguishable from that of lung carcinoma, it is not unusual for these patients to undergo lung resection, only to have pathologic examination reveal the characteristic spherules [6].…”

“…Because the radiographic appearance of coccidioidal nodules is frequently indistinguishable from that of lung carcinoma, it is not unusual for these patients to undergo lung resection, only to have pathologic examination reveal the characteristic spherules [6]. Core needle biopsy has been shown to be reliable at differentiating lesions that cause such nodules [15]; a confirmed diagnosis of coccidioides would save a patient an unnecessary lung resection.…”

“…However, cultures from these specimens are reportedly more sensitive, especially samples from patients with chronic progressive pneumonia [13]. In contrast, direct microscopic study of tissue specimens from transbronchial biopsy, fine-needle aspiration, or core needle biopsy of pulmonary nodules and cavitary lesions is more sensitive than culture, with a yield approaching 75% in some series [15,19]. Absence of granulomatous changes in fine-needle aspirate samples, inability to identify immature spherules, and misinterpretation of atypical epithelial cell change are common factors that lead to failure of diagnosis before surgical resection of pulmonary nodules [15,19,20].…”

Fungal infections of the lung

“…If cultural recovery of the organisms is not successful, bronchoscopy, transbronchial biopsy, throacscopic biopsy,or open-lung biopsy may be needed to make the diagnosis. Cultures of core needle biopsies are, however, insensitive in the detection of specific microorganisms [40]. Serologic testing is extremely valuable in establishing the diagnosis.…”