This presentation provides a comprehensive pathological review of adrenalectomy specimens, detailing the normal anatomy, function, and layers of the adrenal gland. The core focus is on distinguishing between three major differential diagnoses: benign Adrenal Adenoma, malignant Adrenal Cortical Carcinoma (ACC), and Pheochromocytoma. Clinical presentations, gross features (size, color, and weight), and relevant genetic syndromes are discussed for each entity. Crucial practical instruction is given on the proper grossing technique, emphasizing the importance of calculating the trimmed specimen weight—a critical factor for prognostic assessment (tumors under 50g are almost always benign, over 100g often malignant). The presentation concludes with a detailed overview of the pT staging system for ACC and the use of histologic scoring systems (Weiss Score and PASS) to predict malignant behavior.
Pathology Review: Adrenalectomy Specimens and Grossing Techniques
0:00 The Adrenal Gland: The specimen is an adrenalectomy, consisting of the adrenal gland (4-6g normal weight) and periadrenal soft tissue. Adrenal glands regulate metabolism, immune function, salt-water balance, and stress response.
1:54 Adrenal Cortex Layers and Function: The adrenal cortex (golden yellow, 2mm thick) has three layers, each producing different hormones:
Zona Glomerulosa (outer) produces mineralocorticoids.
2:27 Zona Fasciculata (middle) produces glucocorticoids.
Zona Reticularis (inner) produces androgens.
The inner Adrenal Medulla (red-brown) secretes catecholamines.
3:24 Differential Diagnosis: Adrenal Adenoma (Benign): This is the most common adrenal tumor, typically unilateral, solitary, golden yellow, weighing less than 50g and measuring less than 5 cm. It is often non-functional (incidentaloma) but can be associated with Conn or Cushing syndromes.
4:31 Differential Diagnosis: Adrenal Cortical Carcinoma (ACC - Malignant): The most common primary malignancy of the adrenal gland. Gross features include solitary, bulky, yellow-tan/red-brown masses, often featuring necrosis and hemorrhage. Average size is 10-12 cm, and weight typically exceeds 100g.
5:50 ACC Associated Syndromes: ACC risk factors include MEN1, Lynch Syndrome, and Li-Fraumeni. Takeaway: Von Hippel-Lindau (VHL) syndrome is not associated with ACC, but with pheochromocytoma.
6:58 Differential Diagnosis: Pheochromocytoma (Adrenal Medulla): Arises from chromaffin cells and presents clinically with hypertension, episodic headaches, sweating, and tachycardia. Associated with VHL and MEN 2.
7:41 The Pheochromocytoma 10% Rule: 10% are bilateral, 10% are extra-adrenal, 10% occur in children, and 10% are malignant.
10:45 Grossing Step 1: Weight and Malignancy Correlation: Accurate trimmed weight (adrenal gland + mass, with soft tissue removed) is crucial. Neoplasms <50g are almost always benign, while malignant tumors are typically >100g.
11:16 Grossing Step 2: Margins and Sectioning: Do not trim the fat before sectioning the mass entirely, as tumor extension into soft tissue is vital for staging. The resection margin should be inked black.
13:37 Sectioning Strategy: For small lesions (<2 cm), submit the entire mass. For larger lesions (>2 cm), submit representative sections, ensuring sections include the mass in relation to the resection margin, the adjacent uninvolved adrenal gland, and any soft tissue extension (if present).
15:51 pT Staging for ACC: T staging is based on size and invasion: T1 (≤5 cm, no invasion); T2 (>5 cm, no invasion); T3 (local invasion, e.g., into periadrenal fat); and 16:17 T4 (invasion into adjacent organs or major blood vessels like the Vena Cava).
17:28 Prognostic Factors: Distinguishing adenoma from ACC is difficult. The Weiss Score (based on features like mitotic rate, necrosis, capsular invasion) is used; 3 or more criteria suggest malignancy. ACC has a poor prognosis (5-year mortality 50-90%).