Adrenal Cortical Hyperplasia

CLINICAL FEATURES

• Can be diffuse, localized with formation of one or more nodules;

• Almost always bilateral;

• Most cases of diffuse cortical hyperplasia are ACTH dependent, over production from the pituitary gland or a lung tumor;

• Most cases of nodular cortical hyperplasia are unrelated to ACTH production, and are ACTH independent or adrenal dependent;

• A dominant macronodule might be regarded as an adenoma even without symptoms or coexistence of diffuse or micronodular hyperplasia.

GROSS FINDINGS

• Often bilaterally diffuse or multiple nodules;

• Nodules are commonly extrusions of cortex, may project in a hemispheric or "detached" nodule depending on the plane of section;

• The nodules appear discrete and sharply demarcated, and some dominant macronodules may appear encapsulated.

MICROSCOPIC FINDINGS

• Variable architectural patterns: alveolar, trabecular, gyriform ribbon-like, pseudoglandular;

• Nodules are not well-demarcated and blend almost imperceptibly with the adjacent hyperplastic cortex;

• Some nodules are almost entirely composed of lipid-rich cells (yellow nodules grossly);

• Variable mixture of pale-staining, lipid-rich vacuolated cells and lipid-depleted cells with compact, eosinophilic cytoplasm;

• Rarely cells with "ballooned" vacuolated cytoplasm are present;

• Nuclear pleomorphism is often inconspicuous and mitotic figures are rare;

• Pseudoglandular foci may be present with stringy lightly basophilic material, but PAS- and glycogen-;

• Occasionally, lipomatous or myelipomatous foci, or rare bony metaplasia.

CLASSIFICATION

• Diffuse hyperplasia

• Nodular hyperplasia

  • Micronodular (<1.0cm)

  • Macronodular (>1.0cm)

  • Combined micronodular and macronodular

• Combined diffuse and nodular hyperplasia

• Macronodular hyperplasia with marked adrenal enlargement

• Primary pigmented nodular adrenocortical disease: part of Carney's syndrome

• Incidental pigmented nodules

DIFFERENTIAL DIAGNOSES

• Adrenal adenoma: usually single, unilateral and well-demarcated.

REFERENCES

• AFIP, tumor of the adrenal glands and extra-adrenal paraganglia, series 3;

• Rosai and Ackerman's Surgical Pathology, 9th edition.