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.