Related Case: Adrenal mass 1

CLINICAL FEATURES

• May or may not have functional activity;

• Incidence in US: ~1/1,000,000;

• M:F=1:1.5;

• Age: 40-50 years;

• Rarely bilateral;

• 15-38% cases had metastases on initial presentation;

• Most common clinical presentations: abdominal or flank pain, discomfort, or fullness, mass;

• Imaging studies: often large with low intensity areas of necrosis, irregular contour, calcification.

GROSS FINDINGS

• Average weight 510 - 1120 grams;

• Coarsely lobulated appearance with soft, bulging pale-tan or yellow-white nodules;

• Often necrosis, hemorrhage and cystic changes.

MICROSCOPIC FINDINGS

• Architecture: variable, commonly a broad trabecular growth pattern with anastomosing columns and cords of cell, 10-20 or more cells wide, separated by delicate, gaping sinusoids lined by an attenuated endothelial layer; other patterns include nesting, alveolar, solid or diffuse arrangement, and rarely spindle or sarcomatous pattern; occasional myxoid foci;

• Cytology: some tumor cells have lipid-depleted or acidophilic, compact cytoplasm; some contain abundant lipid-rich, pale-staining cytoplasm; cell borders are fairly well defined;

• Nuclei: striking nuclear pleomorphism and hyperchromasia (alone is not sufficient for a diagnosis of malignancy!), occasional hyperlobated or multinucleate with prominent nucleoli or pseudoinclusions;

• Intracytoplasmic hyaline globules: round to oval, refractile, deeply eosinophilic and PAS+;

• Relative common mitoses and atypical mitoses;

• Invasion: vascular invasion, capsular invasion;

• Necrosis: broad and confluent;

• Stromal alterations: broad fibrous bands intersect the tumor and subdivide the tumor into irregular nodules; dystrophic calcifications in 20 cases; myxoid changes, lipomatous or myelipomatous metaplasia.

CRITERIA FOR MALIGNANCY

• A tumor is defined as adrenocortical carcinoma when three or more of the following criteria are met: (1) high nuclear grade, (2) mitotic rate 6 or more per 50 high power fields, (3) atypical mitosis, (4) clear cells less than 25%, (5) a diffuse architecture pattern in more than one-third of the tumor, (6) confluent necrosis, (7) venous invasion, (8) sinusoidal invasion, and (9) capsular invasion;

• Usually large: >100 grams

VARIANTS

• Oncocytic adrenal cortical carcinoma

• Adrenal carcinosarcoma

• Adrenal cortical blastoma

DIFFERENTIAL DIAGNOSES

IMMUNOHISTOCHEMISTRY AND SPECIAL STAINS

• Positive: vimentin, inhibin, Melan-A (Mart-1, A103), Synaptophysin, BCL2, Calretinin (focally);

• Negative: cytokeratin, CD10, RCC, EMA, CEA, Chromogranin;

• Cytokeratin: negative or focally positive.

ELECTRON MICROSCOPIC FINDINGS

• Compact eosinophilic cells have sparse lipid droplets and occasional small, irregular microvillous extension of the cytoplasm;

• Mitochondria are variable with most abundance in the oncocytic type carcinoma.

REFERENCES

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

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

• Sasano H, Suzuki T, Moriya T. Recent advances in histopathology and immunohistochemistry of adrenocortical carcinoma. Endocr Pathol. 2006 Winter;17(4):345-54.

• Differential Immunoprofiles of Hepatocellular Carcinoma, Renal Cell Carcinoma, and Adrenocortical Carcinoma: A Systemic Immunohistochemical Survey Using Tissue Array Technique. Appl Immunohistochem Molecul Morphol, Volume 13(4).December 2005.347-352.

• Melan A (A103) is expressed in adrenocortical neoplasms but not in renal cell and hepatocellular carcinomas. Appl Immunohistochem Mol Morphol. 2003 Dec;11(4):330-3.