ICD-10 Codes for Adrenal Nodule
The primary ICD-10 code for an adrenal nodule is D35.0 (Benign neoplasm of adrenal gland), which is appropriate for most incidentally discovered adrenal masses pending further characterization.
Primary Coding Options
The specific ICD-10 code selection depends on the clinical context and degree of characterization:
Benign Lesions
- D35.0 - Benign neoplasm of adrenal gland (most commonly used for adrenal incidentalomas and adenomas) 1
- D44.1 - Neoplasm of uncertain behavior of adrenal gland (for indeterminate masses requiring further workup) 1
Specific Benign Subtypes
- D35.0 also applies to:
Functional Adenomas
- E24.0 - Pituitary-dependent Cushing's disease
- E24.8 - Other Cushing's syndrome (for cortisol-secreting adenomas, 1-30% of incidentalomas) 1
- E26.0 - Primary hyperaldosteronism (for aldosterone-secreting adenomas, 2-7% of incidentalomas) 1
- D35.0 with E27.5 - Adrenomedullary hyperfunction (for pheochromocytomas, 1.5-14% of incidentalomas) 1
Malignant Lesions
- C74.0 - Malignant neoplasm of cortex of adrenal gland (for adrenocortical carcinoma, 1.2-12% of incidentalomas) 1
- C79.7 - Secondary malignant neoplasm of adrenal gland (for metastases, 0-21% of incidentalomas, though higher in patients with known extra-adrenal malignancy at 25-72%) 1, 3, 4
Other Adrenal Pathology
- E27.8 - Other specified disorders of adrenal gland (for adrenal cysts, 4-22% of incidentalomas) 1
- E27.49 - Other adrenocortical insufficiency (if bilateral involvement causes adrenal insufficiency) 4
Coding Strategy Based on Clinical Scenario
For initial presentation of an incidental finding: Use D35.0 or D44.1 depending on imaging characteristics (D35.0 if <10 HU on unenhanced CT confirming benign lipid-rich adenoma; D44.1 if >10 HU requiring further characterization) 1, 3, 5
After hormonal workup: Add appropriate functional codes (E24.8, E26.0, E27.5) if autonomous hormone secretion is confirmed 1, 3
After definitive characterization: Use specific codes based on final diagnosis (C74.0 for adrenocortical carcinoma if tumor >4 cm with irregular margins or heterogeneous appearance; D35.0 for confirmed benign adenoma) 1
Critical Coding Pitfalls to Avoid
Do not use malignancy codes (C74.0, C79.7) without pathologic confirmation or strong radiologic evidence, as most small adrenal nodules (<4 cm) are benign with malignancy prevalence of only 0.3% in nodules <4 cm and 0.06% risk for primary adrenocortical carcinoma in the general population 3, 6, 7
Avoid using "uncertain behavior" code (D44.1) for masses definitively characterized as benign (HU ≤10 on unenhanced CT), as these are definitively benign lipid-rich adenomas requiring no further workup 1, 3, 5
Include functional codes when appropriate, as approximately 5% of radiologically benign incidentalomas have subclinical hormone production requiring treatment 3, 5