Anthony Kodzo-Grey Venyo*
Abstract
Myelolipomas of the Adrenal Gland (MLOAs) are un-common benign tumors that tend to be found in the adrenal gland but occasionally foci of MLOAs could be found in other extra-adrenal sites. MLOAs consist of mature adipocytes and normal haematopoietic tissue and may contain precursors of red blood and white blood cells including megakaryocytes. MLOAs were previously most commonly diagnosed at autopsy and as incidentalomas at laparotomies for other conditions. MLOAS tend to be more common in the right adrenal gland. MLOAs may be asymptomatic, or in some cases they may present with loin pain, abdominal pain, nausea and vomiting which are non-specific and larger MLOAs may be associated with sudden hemorrhage requiring emergency admission. Radiological imaging with ultrasound scan, CT scan and MRI scan of abdomen are means by which MLOAs con be identified. The adrenal lesions may be hypo-echogenic, mixed-echogenic or hyper-echogenic and at times with foci of calcification. CT scan evidence of fat density component of the adrenal lesion tends to be diagnostic of MLOA but diagnosis can be confirmed by histopathological examination of radiological imaging of mature adipocytes admixed with myeloid/haematopoietic elements. Even though MLOAs tend to be non-functional by themselves; nevertheless, they tend on 10% of occasions to be associated with endocrine disorders some of which include Cushing syndrome, congenital adrenal hyperplasia, primary hyperaldosteronism (Coon syndrome). And for this reason serum cortisol, metanephrine, normetanephrine and vanillylmandelic levels form part of the routine investigation. Treatment options for MLOAS include: conservative/expectant management foe small lesions. Active/surgical treatment for (a) small MLOAs that are increasing in siz on subsequent radiological imaging, (b) Symptomatic MLOAs, MLOAs that are 6 cm or larger, (d) MLOAs associated with hemorrhage, (e) in situations when malignancy cannot be excluded. Various types of active treatment available include: Laparoscopic adrenalectomy (excision of the whole adrenal gland); Laparoscopic excision oftumor(partial-adrenalectomy), leaving intact the normal looking adrenal gland; Laparotomy and open adrenalectomy (excision of the whole adrenal gland); Laparotomy and open excision oftumor(partial-adrenalectomy), leaving intact the normal looking adrenal gland; Selective angiography and super-selective embolization of feeding artery to the MLOA. Considering the fact that MLOAs tend to be benign generally they should be managed in such a way as to minimize morbidity and if the diagnosis is established radiologically and the options of management should include: conservative approach; partial adrenalectomy, or selective angiography and super-selective embolization of the MLOA. The outcome of MLOAs following all the treatment options tends to be good. Total adrenalectomy could be undertaken in cases when malignancy cannot be excluded. The differential diagnosis include: retroperitoneal liposarcoma, fat-containing adreno-cortical carcinoma, teratoma of the adrenal gland, and angiomyolipoma of the kidney.