DISCUSSION

With the rather large size of the tumor and the high HU value, two different diagnosis was considered, malignant pheochromocytoma and adrenocortical carcinoma. Given the rarity of ES/PNET arising from the adrenal gland, we did not initially consider it in the differential diagnosis. This patient exhibited no neuro-endocrine features of Cushing’s syndrome preoperatively. He had a loss of libido and generalized anxiety for 6 months prior to the operation and used benzodiazepine to self-medicate. 2 months before the operation, patient began to manifest gynecomastia, quickly developing to level 4 tanner. However, with rapid use of imaging technics like abdominal ultrasound and MDCT scan with contrast for evaluation of abdominal pain, we were able to quickly find the mass in the right adrenal gland. And while the diagnosis of the type of mass was not definitive, excising it was the right choice retrospectively. Later immunohistochemical studies was done to ascertain the pathology of the mass, leading us to PNET with the pathological evaluation being confirmed by two different pathologists. The diagnosis of PNET tumors is difficult and easily confused with poorly differentiated tumor. The diagnosis is currently based on a combination of light microscopic and immunohistochemical features. In particular, immunohistochemical staining positive for CD-99, neuron-specific enolase, synaptophysin and chromogranin supports its diagnosis[5].
PNET tumors, because they are neuroectodermal tumors, are expected to be functional and secretory. however, most of the functional tumors of the ewing sarcoma family are ACTH secreting[6-9]. While estradiol secreting adrenocortical carcinoma has been reported[10], to the best of our knowledge, no cases of cortisol and estradiol secreting PNET resulting in Cushing’s syndrome has been reported. This tumor was also a retroperitoneal mass which are rare even among PNET tumors arising from the adrenal gland. With no prior publication or report of such case, we believe this case to be the first of its kind to be reported.
In conclusion, here we report a case of adrenal PNET, which adds to the limited number of documented cases in literature. This case shows how different clinical manifestations could be expected from PNET and other neuroectodermal tumors. Our report adds to the few other cases of primary adrenal ES/PNET in the literature.