Epidemiology and clinical manifestations
Adrenocortical carcinoma is rare, yet it has distinct age and gender characteristics. Women are affected 2.5–3 times more often than men. There are two main peaks in incidence: the first decade of life (with 75% of affected children being under 5 years of age) and the 40–50 age group. In men, the pathology usually develops at an older age and is associated with a worse clinical prognosis.
The tumor is associated with several genetic abnormalities: Li-Fraumeni (Li-Fraumeni) and Beckwith-Wiedemann (Beckwith-Wiedemann) syndromes, as well as congenital adrenal hyperplasia.
The functional activity of the mass depends on the patient's age:
- In women and children, tumors are more often functioning. They lead to the development of Cushing's syndrome (Cushing's syndrome) or virilization.
- In adults, non-functioning forms predominate (hyperfunction is observed in only 30–40% of cases).
Overall, the most frequent endocrine manifestation is a combination of hypercortisolism and virilization. This pathology accounts for approximately 27% of all cases of ACTH-independent Cushing's syndrome.
Diagnostic Imaging: CT and MRI
Large adenomas may be visually indistinguishable from carcinomas, so specific imaging patterns are used for differential diagnosis.
Signs of carcinoma on computed tomography (CT):
- The mass is usually unilateral, with a diameter greater than 6 cm.
- The internal structure shows areas of extensive necrosis, fibrosis, hemorrhage, and punctate irregular calcifications.
- CT perfusion assessment (percentage of contrast washout after 10 minutes, washout) allows carcinoma to be distinguished from lipid-rich adenoma with 100% sensitivity and specificity.
Magnetic resonance imaging (MRI) and multislice CT (MSCT): These methods are optimal for assessing tumor spread. On MRI (T1-weighted fat-suppressed images), hyperintense areas of hemorrhage can be detected, and after contrast administration, heterogeneous enhancement with "cold" areas of necrosis is seen.
The tumor frequently invades the adjacent kidney, retroperitoneum, and major vessels. Coronal CT reconstructions reliably demonstrate a tumor thrombus extending into the lumen of the inferior vena cava (IVC). Meanwhile, the mass may displace and compress the liver without true invasion of its parenchyma.
Histological evaluation and prognosis
Reliable criteria of malignancy are considered to be only confirmed local invasion or the presence of distant metastases (liver — 60%, lungs and lymph nodes — 40% each). To assess malignant potential at the cellular level, pathomorphologists use the Weiss score (Weiss score) and its modifications.
The most accurate modern tool is the Helsinki score (Helsinki score, 2015), which outperforms the Weiss score.
Calculation formula: `3 × mitotic rate + 5 × presence of necrosis + Ki67 index` Where the mitotic rate is counted when values exceed 5 mitoses per 50 high-power fields, and the proliferation marker Ki67 is assessed in the most active zone. A value above 8.5 indicates high metastatic potential (sensitivity 100%, specificity 99.4%).
TNM staging (AJCC, 7th edition)
The primary tumor (T) staging system is critically important for choosing treatment tactics. A large mass with suspected invasion is an absolute contraindication to laparoscopic adrenalectomy.
| Grade | Description of the primary tumor (T) |
|---|---|
| T1 | Tumor ≤ 5 cm, not extending beyond the adrenal gland |
| T2 | Tumor > 5 cm, not extending beyond the adrenal gland |
| T3 | Any size, with local invasion (but without involvement of adjacent organs) |
| T4 | Invasion into adjacent organs (kidney, diaphragm, liver, pancreas, vessels) |
Involvement of aortic or retroperitoneal lymph nodes is designated as N1, and the presence of distant lesions as M1.
Briefly: answers to topical questions
What histological criteria are included in the Weiss score?
The Weiss score includes the following histological criteria for assessing malignancy:
- High nuclear grade — enlarged, oval, or segmented nuclei with coarse, hyperchromatic chromatin and easily discernible nucleoli (based on Fuhrman grade III or IV criteria).
- Mitotic rate — greater than 5 per 50 high-power fields.
- Atypical mitoses — aberrant chromosome distribution or an excessive number of mitotic spindles with a multipolar morphological structure.
How is the contrast washout percentage calculated in adrenal CT?
The contrast washout percentage is calculated by comparing tissue density values on scans obtained 60 seconds after contrast administration and delayed scans at 15 minutes. To calculate the Relative Contrast Enhancement Washout, the formula is used: % RCEW = [(CECT density at 60 sec - Delayed density) / CECT density at 60 sec] × 100. The Absolute Contrast Enhancement Washout percentage is also calculated using a formula based on density values in Hounsfield units (HU).
With which benign adrenal tumors is differential diagnosis of adrenocortical carcinoma performed?
Differential diagnosis of adrenocortical carcinoma is performed with the following benign adrenal masses:
- Adrenal adenoma (Adrenal adenoma) — the most frequent incidentaloma; large adenomas can be indistinguishable from carcinomas.
- Myelolipoma (Myelolipoma) — a benign mass composed of adipose tissue.
- Adrenal cyst (Adrenal cyst) — a rare benign condition, usually discovered incidentally.
- Nodular hyperplasia — a benign condition classified among non-functioning incidentalomas.
Class and exam questions
Can a large adenoma be clinically distinguished from adrenocortical carcinoma?
Based on size alone — no, because large adenomas and cancer can look similar. CT perfusion is required to assess contrast washout and look for specific signs of malignancy (necrosis, vascular invasion).
Why can adrenocortical carcinoma cause fever?
The tumor is characterized by rapid growth and frequently undergoes massive central necrosis, which causes a systemic inflammatory response and fever, mimicking an infectious process.
Which organs are most frequently affected by metastases in this pathology?
Metastases are most frequently found in the liver (about 60% of cases), as well as in regional lymph nodes and lungs (40% each).
What else to study on this topic
- ACTH-independent Cushing's syndrome
- CT perfusion (Washout) in adrenal diagnostics
- Tumor thrombosis of the inferior vena cava on CT
- Histological Weiss score
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