Negative predictive value of imaging-guided abdominal biopsy results: cytologic classification and implications for patient management

Interventional uroradiology

With advances in imaging capabilities and percutaneous instruments, many urologic diseases that were once managed surgically are now managed with minimally invasive image-guided techniques. Interventional uroradiology has evolved from simple renal biopsies for diagnostic confirmation, to percutaneous management of stones, to ablation of renal and adrenal tumors. Central to this evolution is the close cooperation with the urologist and nephrologist, each of whom provides specific skill sets and knowledge that can be used to successfully manage the patient. The purpose of this article is to detail the wide range of image-guided interventional techniques, including a discussion of indications, methods, success rates, and complications.

Renal Masses in the Adult Patient: The Role of Percutaneous Biopsy

Although percutaneous renal mass biopsy with cross-sectional imaging guidance has long been considered to be safe and accurate, there have been recent advances in imaging, interventional, and cytologic techniques that have increased the role of percutaneous biopsy in the diagnosis of renal masses. Today, biopsy plays a fundamental role in the care of patients with a renal mass. Biopsy results are used to confirm the diagnosis of renal cancers, metastases, and infections, and there is increasing evidence to suggest that biopsy can help subtype and grade many primary renal cancers. Because a considerable fraction of small solid renal masses are benign and do not need treatment, there is an increasing need to diagnose them. Biopsy after a full imaging work-up can help prevent unnecessary and potentially morbid surgical and ablation procedures in a substantial number of patients. Although more data are needed to understand the overall accuracy of biopsy for the diagnosis of benign lesions, many can be diagnosed with the aid of biopsy findings. This article reviews reported experience with percutaneous renal mass biopsy, discusses the technical factors that contribute to results, and details seven specific clinical settings that should prompt the clinician to consider percutaneous biopsy when encountering a renal mass.

Efficacy of CT-guided percutaneous needle biopsy in the diagnosis of malignant lymphoma at first presentation

PURPOSE

The aim of this study was to evaluate retrospectively the accuracy and reliability of CT-guided percutaneous biopsy as an alternative to surgical biopsy in a selected population of patients without superficial enlarged lymph nodes and a final diagnosis of malignant lymphoma at first presentation.

METHODS

The results of 145 CT-guided needle biopsies in 137 patients with malignant lymphoma at its first presentation and without superficial enlarged lymph nodes were analyzed retrospectively. Biopsies were performed in 24 patients with Hodgkin's disease (HD) and 113 with non-Hodgkin lymphoma (NHL). Factors such as patient's sex, age, type of lymphoma and biopsy site were evaluated to detect factors that could influence the success rate of the procedure.

RESULTS

Biopsy specimens were diagnostic in 101 of the 113 patients with NHL and in 18 of the 24 patients with HD. Repeating of a previously nondiagnostic biopsy was successful in 7 out of 13 patients with NHL. No positive results were obtained, repeating the inconclusive biopsy in six patients with HD.

CONCLUSIONS

Our results suggest that percutaneous CT-guided biopsy is a useful and reliable tool in the diagnosis and classification of malignant lymphomas in patients without superficial lymphadenopathy and can be considered as an alternative to surgical sampling. However, little advantages were obtained, repeating previously inconclusive biopsies: In these cases, surgical sampling is mandatory.

Telomerase activity predicts malignancy in percutaneous image-guided needle biopsy specimens of the abdomen and pelvis

PURPOSE

To determine prospectively if assessment of telomerase activity in percutaneous needle biopsy specimens improves sensitivity and specificity in the diagnosis of abdominal and pelvic malignancy.

MATERIALS AND METHODS

The study was approved by the institutional review board, and written informed consent was obtained from all patients. A prospective double-blinded design was used to assess telomerase activity in abdominal and pelvic biopsy specimens from 99 patients (64 men, 35 women; age range, 22-87 years). After the clinical sample was retrieved, a study specimen from an extra needle pass was divided and independently analyzed for cytologic characteristics and telomerase activity. The final diagnosis was based on chart review at a minimum 1-year follow-up. Statistical analyses included sensitivity, specificity, and accuracy of cytologic examination and/or telomerase activity in predicting malignancy.

RESULTS

Data from study specimens indicated that the sensitivity, specificity, and accuracy of telomerase activity (n=99) in predicting malignancy were 55%, 79%, and 60%, respectively. For cytologic examination (n=86), the sensitivity, specificity, and accuracy in predicting malignancy were 74%, 94%, and 78%, respectively. Combining the two tests (n=86) and classifying a positive reading with either test as malignant improved sensitivity (83%) (P <.05) without altering specificity (76%). In 20 patients who had clinical sample reports that were classified as indeterminate, telomerase activity (n=20) yielded a higher sensitivity (62%) (P <.05) and similar specificity (86%) compared with cytologic examination (n=15), which yielded a sensitivity of 11% and a specificity of 83%.

CONCLUSION

In percutaneous biopsy specimens of the abdomen and pelvis, the combination of cytologic examination and telomerase activity yielded an increased sensitivity in predicting malignancy. In addition, assessing telomerase activity can help identify cancer even when cytologic results are indeterminate.

Evaluation of patients referred for percutaneous ablation of renal tumors: importance of a preprocedural diagnosis

OBJECTIVE

Percutaneous ablation of renal cell carcinoma has the potential to be as effective as partial nephrectomy. Because the entire tumor cannot be examined at pathology, diagnosis relies solely on imaging and percutaneous biopsy. Diagnoses of cancer have been rendered using imaging alone in some clinical trials of percutaneous ablation. If these trials inadvertently included benign masses, the efficacy of ablation was overestimated. Therefore, we sought to determine the prevalence of benign masses in a population of patients referred for percutaneous tumor ablation of presumed renal cell carcinoma.

SUBJECTS AND METHODS

Twenty-seven patients were referred by urologists for MRI-guided cryotherapy of suspected renal cell carcinoma. Renal masses ranged from 1.0 to 4.6 cm (mean, 2.2 cm) in diameter. The CT, MRI, and percutaneous biopsy findings were tabulated and compared with surgical and imaging follow-up.

RESULTS

Ten patients (37%) had a benign renal mass, including three angiomyolipomas, that had no evidence of fat on CT or MRI. Three masses were proven benign by biopsy, three by imaging, and four by a combination of biopsy and imaging. The masses in the remaining 17 patients were ablated. Biopsy revealed malignant cells in 10, suspicious cells in four, and atypical cells in two; one was nondiagnostic.

CONCLUSION

A substantial percentage of patients referred for percutaneous ablation of renal tumors had benign masses. If CT or MRI alone cannot be used to diagnose a benign entity, patients should undergo a biopsy before the treatment session.

Percutaneous biopsy of renal masses: sensitivity and negative predictive value stratified by clinical setting and size of masses

OBJECTIVE

The purpose of our retrospective study was to evaluate the sensitivity and negative predictive value of percutaneous biopsy of renal masses stratified by clinical setting and the size of the mass.

MATERIALS AND METHODS

We categorized 115 consecutive percutaneous biopsies of renal masses in 113 patients into four clinical settings and three groups of mass sizes. The sensitivity and negative predictive value were computed (with 95% confidence intervals [CI]) for each clinical setting and for each size group.

RESULTS

For all procedures (n = 115), the sensitivity and negative predictive value were 90% (95% CI, 81-95%) and 64% (95% CI, 44-81%), respectively. For patients with a known malignancy who presented with a renal mass (n = 55), the sensitivity and negative predictive value were 90% (95% CI, 78-96%) and 38% (95% CI, 10-74%), respectively. For patients with no known malignancy and suspected unresectable tumor (n = 36), the sensitivity and negative predictive value were 92% (95% CI, 76-98%) and 0%, respectively. For patients with no known malignancy who presented with a cystic mass (n = 16), the sensitivity and negative predictive value were 33% (95% CI, 2-87%) and 87% (95% CI, 58-98%), respectively. For patients who were not surgical candidates with a renal cell carcinoma (n = 8) that was thought to be resectable, both the sensitivity and negative predictive value were 100%. For masses 3 cm and less (n = 31), the sensitivity and negative predictive value were 84% (95% CI, 63-95%) and 60% (95% CI, 27-86%), respectively. For masses between 4 and 6 cm (n = 42), the sensitivity and negative predictive value were 97% (95% CI, 83-100%) and 89% (95% CI, 51-99%), respectively. For masses greater than 6 cm (n = 42), the sensitivity and negative predictive value were 87% (95% CI, 71-95%) and 44% (95% CI, 15-77%), respectively.

CONCLUSION

Percutaneous renal mass biopsy has a high sensitivity in three clinical settings: patients with a known malignancy, patients with no known malignancy and suspected unresectable tumor, and nonsurgical patients with a mass suspected to be a resectable renal cell carcinoma. Negative results in small (< or = 3 cm) and large (> 6 cm) masses should be viewed with caution.

Predictive value of benign percutaneous adrenal biopsies in oncology patients

PURPOSE

Percutaneous CT guided biopsy is accepted as a safe procedure for the diagnosis of indeterminate adrenal masses in oncologic patients. The purpose of this study was to evaluate the accuracy of a 'negative for tumour' adrenal biopsy in the oncologic patient population by assessing subsequent outcome including clinical course, size and imaging characteristics of the adrenal lesions on follow-up imaging studies and pathological findings at re-biopsy or following adrenal mass resection.

MATERIALS AND METHODS

Retrospective analysis of 225 oncological patients (FM, 128;87; age range 33-87 years, mean age 66 years) who had undergone CT guided biopsies of an adrenal mass over a 5-year period was performed. Those patients with a report consistent with 'negative for malignancy' were evaluated by reviewing the medical records for patient demographics, primary malignancy, histology of adrenal tumour, subsequent surgical interventions, repeat adrenal biopsy under image guidance, by open surgery or at autopsy, subsequent abdominal imaging in which the adrenal gland was imaged, and long-term outcome including hospital admissions, or death.

RESULTS

Of the 225 CT-guided adrenal biopsies performed, 41 (18%) were negative for neoplasm. The primary neoplasm in these 41 patients included lung cancer (n=32), breast (n=5), renal cell carcinoma (n=2), bladder (n=1), and prostate (n=1). The size of the adrenal lesions ranged from 2.8-5 cm. Of the 41 biopsies, which were negative for tumour; 10 were identified as adenomas and the rest showed benign adrenal cortical cells or hyperplasia on cytopathology and histopathology. Repeat biopsies were obtained in 13/41 (31%) patients; whereas 2/41 (5%) had their adrenal gland analyzed on post mortem examination. None of these 15 repeat evaluations yielded tumour.

CONCLUSION

In oncological patients, pathological analysis of tissue samples obtained by CT-guided percutaneous biopsy, suggesting benign aetiology, is reliable and predicts a benign course on long-term follow-up. A negative or benign pathology result for a CT guided percutaneous adrenal biopsy can be regarded as a true negative evaluation in oncological patients with no necessity to repeat the biopsy.

Image-guided coaxial fine needle aspiration biopsy with a side-exiting guide

PURPOSE

The aim of this study was to evaluate the diagnostic accuracy and complication rates of a side-exiting coaxial needle system for fine needle aspiration (FNA) biopsies.

METHOD

Between 1995 and 1998, 127 nonconsecutive biopsies were performed on 122 patients (74 males, 48 females). CT guidance was used in 111, ultrasound guidance was used in 14, and both were used in 2 biopsies. Patient history, biopsy site, needle performance, complications, and cytology results were recorded.

RESULTS

Diagnostic rate and accuracy were 92.9 and 99.2%, respectively. There were minor complications from 14 biopsies, and all of them arose from chest biopsies: pneumothorax in 13 of 47 and hemoptysis in 1 of 47. There were no major complications.

CONCLUSION

The side-exiting coaxial needle system is a safe and effective alternative to the conventional end-exiting coaxial needle system for performance of image-guided FNA biopsies.

Interventional radiology procedures in the liver. Biopsy, drainage, and ablation

Radiologically guided interventional procedures in the liver have continually increased, in number and variety, over the years. Factors promoting these advances include new technology, innovative ideas, and growing acceptance by clinicians and patients. Percutaneous biopsy and drainage procedures are firmly established techniques with low complication rates. Ablation by injected substances is useful for treating certain tumor types. The most exciting development is the introduction of percutaneous thermal techniques for tumor ablation. Although more experience is needed to optimize the use of focal thermal ablation, early results seem promising.