The differential diagnosis of adrenal incidentalomas with non-benign appearence on unenhanced computed tomography: a retrospective study

• 發表在: Alʹmanah Kliničeskoj Mediciny
• Main Authors: Irena A. Ilovayskaya, Anna Y. Lugovskaya, Alexey A. Glazkov, Timur A. Britvin, Larisa E. Gurevich, Valentina E. Shikina
• 格式: Article
• 語言: 俄语
• 出版: MONIKI 2025-07-01
• 主題: adrenal incidentaloma; pheochromocytoma; adrenocortical carcinoma; hormonally non-functioning adrenal adenomas; arterial hypertension; computed tomography; phenotype; differential diagnostics
• 在線閱讀: https://almclinmed.ru/jour/article/viewFile/17415/1738
• ISSN: 2072-0505; 2587-9294

Background: Сomputed tomography (CT) is considered as the gold standard for imaging the adrenal tumors. Tumor size and native density in unenhanced CT images are widely used to predict tumor malignancy, however, their diagnostic accuracy and the added value of clinical and anamnestic data remain uncertain. Objective: To identify clinical markers that possibly could differentiate pheochromocytoma (PCC), adrenocortical cancer (ACC), and hormonally non-functioning adrenal adenoma (NAA) in patients with adrenal masses of non-benign appearance on unenhanced CT. Methods: This was a single-center observational retrospective selective non-controlled study of 123 patients who underwent adrenalectomy between January 2011 and December 2023. All lesions showed native density ≥ 10 Hounsfield units [HU] or maximum diameter ≥ 4 cm, or both features on pre-operative CT. Histology examination confirmed 63 PCC, 30 ACC and 30 NAA. Clinical presentation, comorbidities, laboratory tests and imaging findings were reviewed. Results: Paroxysmal type of arterial hypertension (AH) was common across all groups; its presence did not aid discrimination. AH grade 3, however, prevailed in the patients with PCC only. Patients with an adrenal mass and AH grade 3 had the high probability of PCC presence (odds ratio, OR: 5.978, 95% confidence interval, CI [2.620–13.640]; p 0.001). AH grade distribution was similar in the ACC and NAA groups. Headache (57.1%), palpitations (48.3%) and a history of peptic ulcer disease (25.4%) were also characteristic of PCC. In contrast, generalized weakness and lumbar pain predominated in ACC (63.3% and 60%, respectively) and NAA (56.7% and 73.3%). Tumors with native density of ≥ 10 HU and size 4 cm (the malignant CT phenotype) were found in 90% (27/30) of ACC, 62% (39/63) of PCC, and 36.7% (11/30) of NAA cases. This CT appearance detected a malignant lesion (PCC or ACC) with 71% sensitivity and 63% specificity, while the chance to find NAA was low (OR: 0.237, 95% CI [0.097–0.555]; р 0.001). Tumors with native density ≥ 10 HU and tumor size of 4 cm were found in similar proportions in PCC (36.5%, 23/63) and NAA (30%, 9/30) groups, indicating a low probability of ACC (OR: 0.212, 95% CI [0.048–0.659]; р = 0.016) and focusing the differential diagnosis on PCC versus NAA. Tumors with native density 10 HU and size ≥ 4 cm were rare in PCC (1/63, 1.6%) and absent in ACC, yet presented in 10/30 (33.3%) NAA cases. This CT phenotype is associated with low risk of malignancy (OR: 0.022, 95% CI [0.001–0.123]; р 0.001), although insensitive (33%), it had a specificity of 98.9% for benign NAA. Conclusion: In adrenal tumors of the malignant CT phenotype, the differential diagnosis should be made between ACC and PCC, while the presence of NAA is highly unlikely. In tumors with native density of 10 HU and tumor size of 4 cm, the differential diagnosis should first consider PCC and NAA, while the chance to identify ACC is low. The adrenal masses with the native density of 10 HU and tumor size of ≥ 4 cm were strongly suggestive of benign NAA, with an exceedingly low risk of cancer.