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Letters Reply: Adrenal Biopsy Is Recommended to Differentiate Benign Versus Malignant Metastasis of Primary Adrenal Lesions We thank Dr. Pfister [1] for his interest in our article [2] and for sharing an interesting and unusual case of a patient with bilateral enlarged hyperfunctioning adrenal glands with masslike appearance of one of the glands. We agree that percutaneous biopsy has excellent sensitivity and specificity in diagnosing adrenal metastasis. Percutaneous biopsy is usually performed with CT guidance and has been shown to be safe, with 85–96% diagnostic accuracy and a complication rate of 3–9% [3–5]. However, we do not agree with the blanket statement by Dr. Pfister [1] that “radiologic assessments on the basis of CT… are not sufficient for the diagnostic analysis of adrenal nodules. Moreover, … adrenal biopsies are strongly recommend to determine the status of metastasis or primary adrenal lesion….” Routine contrast-enhanced CT images are often insufficient to characterize adrenal masses, which we discussed in our article [2]; however, unenhanced CT and adrenal CT with washout have been shown to be highly accurate in characterizing adrenal masses, eliminating the need for biopsy [6, 7]. Indeed, advances in adrenal imaging have led to a decreased need for adrenal biopsy [3], and its role has evolved, mainly to confirm or exclude malignancy in the few cases in which imaging findings are inconclusive, or when an adrenal mass is enlarging [8]. The case presented by Dr. Pfister is highly unusual, and the large adrenal mass was appropriately biopsied given its suspicious imaging appearance in the setting of bilateral adrenal enlargement, presumed renal cancer, and a strong family history of congenital adrenal hyperplasia. We also realize that no imaging study is 100% specific, and a small fraction of benign adrenal lesions can be metabolically active [9]. As more adrenal incidentalomas are discovered because of increased use of imaging and improved spatial resolution of imaging devices, there has been a focus on optimizing
the workup, particularly given the high prevalence of benign disease. One of the factors to consider in the adrenal workup is its morphology on the original imaging examination, and the focus of our study was to assess whether imaging appearance on the original contrast-enhanced CT (not dedicated adrenal imaging) can help triage the workup. We found that adrenal masses with irregular margins or a thick enhancing rim are likely to be malignant but that smooth margins and homogeneous density can be seen in both benign and small malignant adrenal masses and are insufficient for characterization [2]. Congenital adrenal hyperplasia is an uncommon entity, usually diagnosed during childhood or the neonatal period and confirmed biochemically. Imaging workup is uncommon. On imaging, the adrenal glands may be diffusely enlarged, but occasionally masslike nodules can be present [10–12], potentially posing a diagnostic problem. In summary, we stress that on routine contrast-enhanced CT, adrenal masses with imaging features associated with malignancy are frequently malignant, whereas benign and small malignant adrenal lesions can both appear benign. In contrast to the author’s suggestion, most adrenal masses can be successfully characterized by dedicated adrenal imaging, precluding biopsy for diagnosis. Julie H. Song William W. Mayo-Smith Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI DOI:10.2214/AJR.14.12637 WEB—This is a web exclusive article.
References 1. Pfister C. Adrenal biopsy is recommended to differentiate benign versus malignant metastasis of primary adrenal lesions. (letter) AJR 2014; 203:[web]W340–W341 2. Song JH, Grand DJ, Beland MD, Chang KJ,
Machan JT, Mayo-Smith WW. Morphologic features of 211 adrenal masses at initial contrast-enhanced CT: can we differentiate benign from malignant lesions using imaging features alone? AJR 2013; 201:1248–1253 3. Paulsen SD, Nghiem HV, Korobkin M, Caoili EM, Higgins EJ. Changing role of imaging-guided percutaneous biopsy of adrenal masses: evaluation of 50 adrenal biopsies. AJR 2004; 182:1033–1037 4. Silverman SG, Mueller PR, Pinkney LP, Koenker RM, Seltzer SE. Predictive value of image-guided adrenal biopsy: analysis of results of 101 biopsies. Radiology 1993; 187:715–718 5. Welch TJ, Sheedy PF II, Stephens DH, et al. Percutaneous adrenal biopsy: review of a 10-year experience. Radiology 1994; 193:341–344 6. Boland GW, Lee MJ, Gazelle GS, et al. Characterization of adrenal masses using unenhanced CT: an analysis of the CT literature. AJR 1998; 171:201–204 7. Caoili EM, Korobkin M, Francis IR, et al. Adrenal masses: characterization with combined unenhanced and delayed enhanced CT. Radiology 2002; 222:629–633 8. Berland LL, Silverman SG, Gore RM, et al. Managing incidental findings on abdominal CT: white paper of the American College of Radiology Incidental Findings Committee. J Am Coll Radiol 2010; 7:754–773 9. Boland GWL, Dwamena BA, Sangwaiya MJ, et al. Characterization of adrenal masses by using FDG PET: a systematic review and meta-analysis of diagnostic test performance. Radiology 2011; 259:117–126 10. Giacaglia LR, Mendonca BB, Madureira G, et al. Adrenal nodules in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency: regression after adequate hormonal control. J Pediatr Endocrinol Metab 2001; 14:415–419 11. Harinarayana CV, Renu G, Ammini AC, et al. Computed tomography in untreated congenital adrenal hyperplasia. Pediatr Radiol 1991; 21:103– 105 12. Falke TH, van Seters AP, Schaberg A, Moolenaar AJ. Computed tomography in untreated adults with virilizing congenital adrenal cortical hyperplasia. Clin Radiol 1986; 37:155–160
AJR 2014; 203:W342 0361–803X/14/2033–W342 © American Roentgen Ray Society
W342
AJR:203, September 2014
Letters Reply: Adrenal Biopsy Is Recommended to Differentiate Benign Versus Malignant Metastasis of Primary Adrenal Lesions We thank Dr. Pfister [1] for his interest in our article [2] and for sharing an interesting and unusual case of a patient with bilateral enlarged hyperfunctioning adrenal glands with masslike appearance of one of the glands. We agree that percutaneous biopsy has excellent sensitivity and specificity in diagnosing adrenal metastasis. Percutaneous biopsy is usually performed with CT guidance and has been shown to be safe, with 85–96% diagnostic accuracy and a complication rate of 3–9% [3–5]. However, we do not agree with the blanket statement by Dr. Pfister [1] that “radiologic assessments on the basis of CT… are not sufficient for the diagnostic analysis of adrenal nodules. Moreover, … adrenal biopsies are strongly recommend to determine the status of metastasis or primary adrenal lesion….” Routine contrast-enhanced CT images are often insufficient to characterize adrenal masses, which we discussed in our article [2]; however, unenhanced CT and adrenal CT with washout have been shown to be highly accurate in characterizing adrenal masses, eliminating the need for biopsy [6, 7]. Indeed, advances in adrenal imaging have led to a decreased need for adrenal biopsy [3], and its role has evolved, mainly to confirm or exclude malignancy in the few cases in which imaging findings are inconclusive, or when an adrenal mass is enlarging [8]. The case presented by Dr. Pfister is highly unusual, and the large adrenal mass was appropriately biopsied given its suspicious imaging appearance in the setting of bilateral adrenal enlargement, presumed renal cancer, and a strong family history of congenital adrenal hyperplasia. We also realize that no imaging study is 100% specific, and a small fraction of benign adrenal lesions can be metabolically active [9]. As more adrenal incidentalomas are discovered because of increased use of imaging and improved spatial resolution of imaging devices, there has been a focus on optimizing
the workup, particularly given the high prevalence of benign disease. One of the factors to consider in the adrenal workup is its morphology on the original imaging examination, and the focus of our study was to assess whether imaging appearance on the original contrast-enhanced CT (not dedicated adrenal imaging) can help triage the workup. We found that adrenal masses with irregular margins or a thick enhancing rim are likely to be malignant but that smooth margins and homogeneous density can be seen in both benign and small malignant adrenal masses and are insufficient for characterization [2]. Congenital adrenal hyperplasia is an uncommon entity, usually diagnosed during childhood or the neonatal period and confirmed biochemically. Imaging workup is uncommon. On imaging, the adrenal glands may be diffusely enlarged, but occasionally masslike nodules can be present [10–12], potentially posing a diagnostic problem. In summary, we stress that on routine contrast-enhanced CT, adrenal masses with imaging features associated with malignancy are frequently malignant, whereas benign and small malignant adrenal lesions can both appear benign. In contrast to the author’s suggestion, most adrenal masses can be successfully characterized by dedicated adrenal imaging, precluding biopsy for diagnosis. Julie H. Song William W. Mayo-Smith Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI DOI:10.2214/AJR.14.12637 WEB—This is a web exclusive article.
References 1. Pfister C. Adrenal biopsy is recommended to differentiate benign versus malignant metastasis of primary adrenal lesions. (letter) AJR 2014; 203:[web]W340–W341 2. Song JH, Grand DJ, Beland MD, Chang KJ,
Machan JT, Mayo-Smith WW. Morphologic features of 211 adrenal masses at initial contrast-enhanced CT: can we differentiate benign from malignant lesions using imaging features alone? AJR 2013; 201:1248–1253 3. Paulsen SD, Nghiem HV, Korobkin M, Caoili EM, Higgins EJ. Changing role of imaging-guided percutaneous biopsy of adrenal masses: evaluation of 50 adrenal biopsies. AJR 2004; 182:1033–1037 4. Silverman SG, Mueller PR, Pinkney LP, Koenker RM, Seltzer SE. Predictive value of image-guided adrenal biopsy: analysis of results of 101 biopsies. Radiology 1993; 187:715–718 5. Welch TJ, Sheedy PF II, Stephens DH, et al. Percutaneous adrenal biopsy: review of a 10-year experience. Radiology 1994; 193:341–344 6. Boland GW, Lee MJ, Gazelle GS, et al. Characterization of adrenal masses using unenhanced CT: an analysis of the CT literature. AJR 1998; 171:201–204 7. Caoili EM, Korobkin M, Francis IR, et al. Adrenal masses: characterization with combined unenhanced and delayed enhanced CT. Radiology 2002; 222:629–633 8. Berland LL, Silverman SG, Gore RM, et al. Managing incidental findings on abdominal CT: white paper of the American College of Radiology Incidental Findings Committee. J Am Coll Radiol 2010; 7:754–773 9. Boland GWL, Dwamena BA, Sangwaiya MJ, et al. Characterization of adrenal masses by using FDG PET: a systematic review and meta-analysis of diagnostic test performance. Radiology 2011; 259:117–126 10. Giacaglia LR, Mendonca BB, Madureira G, et al. Adrenal nodules in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency: regression after adequate hormonal control. J Pediatr Endocrinol Metab 2001; 14:415–419 11. Harinarayana CV, Renu G, Ammini AC, et al. Computed tomography in untreated congenital adrenal hyperplasia. Pediatr Radiol 1991; 21:103– 105 12. Falke TH, van Seters AP, Schaberg A, Moolenaar AJ. Computed tomography in untreated adults with virilizing congenital adrenal cortical hyperplasia. Clin Radiol 1986; 37:155–160
AJR 2014; 203:W342 0361–803X/14/2033–W342 © American Roentgen Ray Society
W342
AJR:203, September 2014
