Shift from Conn's syndrome to Cushing's syndrome in a recurrent adrenocortical carcinoma

Adrenocortical tumors may originate from the zona glomerulosa, zona fasciculata, or zona reticularis and be associated with syndromes due to overproduction of mineralocorticoids, glucocorticoids, or androgens respectively. We report an unusual case of recurrent adrenocortical carcinoma (ACC), which seems to contradict the paradigm of functional adrenal zonation.

A male patient presented with severe primary aldosteronism due to an ACC, which relapsed after adrenalectomy and adjuvant mitotane therapy. After removal of the tumor recurrence and eight cycles of chemotherapy with etoposide, doxorubicin and cisplatin, the patient presented again with ACC masses, but in association with overt Cushing's syndrome and normal aldosterone levels.

Extensive pathologic examination showed that this shift in steroid hormone production was paralleled by an attenuation of tumor cell atypia and polymorphism, whereas gene expression profile analysis demonstrated a change in expression of adrenal steroidogenic enzymes. Moreover, cancer progression was associated with overexpression of the inhibin-alpha subunit, which could have contributed to the phenotypic changes.

This case of recurrent ACC demonstrates that adrenocortical cells can reverse their differentiation program during neoplastic progression and change their specific hormone synthesis, as a consequence of modifications in the expression profile of steroidogenic enzymes and cofactors. We hypothesize that this shift in steroid hormone secretion is a consequence of chromosome amplification induced by chemotherapy. These findings, besides opening new perspectives to study adrenocortical cell plasticity and potential, demonstrate how conventional clinical and pathologic evaluation can be combined with genomic analysis in order to dissect thoroughly the biology of cancer.