Multiple myeloma concealed by adrenal Cushing syndrome: a case report and review of the literature

BACKGROUND: Cushing syndrome coexisting with multiple myeloma has been previously described in a few reports. Overlapping clinical manifestations can lead to misdiagnoses. CASE PRESENTATION: We presented an extremely rare case of a 33-year-old Thai woman with concomitant kappa light chain myeloma with adrenal Cushing syndrome, both of which were related to skeletal manifestations. A precedence report indicated that treatment of the Cushing syndrome could exacerbate the myeloma symptoms. Therefore, we were faced with the dilemma of which disease should be addressed first. We decided to treat our patient with a combination chemotherapy followed by an autologous stem cell transplant. Subsequently, a left laparoscopic adrenalectomy was successfully undertaken. CONCLUSION: We have reported the first association between adrenocorticotropic hormone-independent Cushing syndrome resulting from a left autonomous cortisol-secreting adrenal adenoma, and multiple myeloma. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13256-018-1731-y) contains supplementary material, which is available to authorized users.