Adrenal Cortical Carcinoma

Adrenal cortical carcinoma (also known as adrenocortical carcinoma) is a malignant neoplasm that originates from the adrenal cortex. It is rare, with an estimated incidence of 1–2 per million population.

There is a bimodal age distribution, with increased incidence in children younger than 5 years of age and in adults in their 30s and 40s. Adrenal cortical carcinomas are more common in women, in whom the tumors tend to be well-differentiated and functional. The tumors are also more likely to be functional in children (>85%) compared to adults (< 30%). Functional tumors can secrete cortisol (Cushing syndrome), androgens (virilization), estrogens (feminization), and/or aldosterone (Conn syndrome). The "and/or" in the previous sentence is meant to indicate that unlike benign adrenal cortical tumors, which tend to secrete a single class of steroid, adrenal cortical carcinomas can secrete various types of steroids. Indeed, rapidly progressing Cushing syndrome, often with virilization, is a characteristic presentation in adults.

Unfortunately, most tumors in adults are non-functional, and patients typically present late with mass effect from a large tumor, with 30% of patients presenting with metastatic disease.

Most cases are sporadic; however, adrenal cortical carcinomas have been associated with Li-Fraumeni syndrome, Carney complex (not to be confused with the Carney triad), Beckwith-Wiedemann syndrome, familial adenomatous polyposis, and multiple endocrine neoplasia, type 1.

Imaging findings at CT include a large (> 4 cm) hemorrhagic and necrotic mass with small areas of fat (from cortisol and its fatty precursors in functional tumors) and calcification (seen in ~30% of patients.

Smaller lesions may be homogeneous on unenhanced CT, but demonstrate heterogeneous enhancement and central low attenuation from necrosis.

MRI findings include a heterogeneous mass with areas of T1 hyperintensity corresponding to hemorrhage. The lesions are predominantly T2-hyperintense. Foci of intracellular lipid corresponding to cortisol and its fatty precursors can be demonstrated as non-uniform areas of signal loss on chemical shift imaging.

References

Bharwani N, Rockall AG, Sahdev A, Gueorguiev M, Drake W, Grossman AB, Reznek RH. Adrenocortical carcinoma: the range of appearances on CT and MRI. AJR Am J Roentgenol. 2011 Jun;196(6):W706-14.