惡性潛能未定之腎上腺皮質嗜酸細胞瘤案例報告

江長和¹、張延驊^1,2、黃志賢^1,2 

¹臺北榮民總醫院 泌尿部

²國立陽明交通大學醫學院泌尿學科 書田泌尿科學研究中心

A Case Report: Oncocytic Adrenocortical Tumor of Uncertain Malignant Potential

Chang Ho Chiang¹, Yen-Hwa Chang^1,2, William J. Huang^1,2 

¹ Department of Urology, Taipei Veterans General Hospital 

² Department of Urology, College of Medicine and Shu-Tien Urological Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan 

Introduction:

Oncocytic tumors are rare neoplasms composed of epithelial cells with abundant acidophilic, granular cytoplasm. They had been reported in variable organs including kidneys, thyroid, parathyroid, salivary and pituitary glands, ovaries, and lungs. The incidence of oncocytic adrenocortical tumors of uncertain malignant potential is unknown because the disease is extremely rare with only few cases reported in the literature. Herein, we report a case of oncocytic adrenocortical tumor of uncertain malignant potential in a young female patient.

Case report:

A 39-year-old female had past medical history of anemia, hypothyroidism and asthma. She suffered from chronic intermittent abdominal pain and left flank pain for about 5 years and computed tomography (CT) scan in other hospital revealed a heterogeneous, faint enhancing mass lesion sized 10x7.7 cm at left supra-renal region with no enlarged lymphadenopathy in the whole abdomen.

She came to our out-patient clinic for second opinion. Lab data including blood, urine routine and blood biochemistry study were in normal range. Her adrenal hormone profiles (ACTH/cortisol, PRA/aldosterone, sex hormones, plasma catecholamine, 24 hours urine VMA/catecholamine), thyroid function profiles were all WNL. She then underwent transabdominal adrenalectomy under the impression of huge left adrenal non-functioning tumor with minimal (30 cc) blood loss and uneventful recovery.

Grossly, a tumor 10.1 x 6.6 x 3.0 cm in size attaching to adrenal gland (measuring 5.2x1.7x1.6 cm). The tumor cut surface showed a solid dark red appearance with some brown mucinous component. Sections of the tumor revealed no venous or capsular invasion, no increase of mitosis rate nor atypical mitosis. Immunohistochemically, the tumor cells are immunoreactive for melan-A, while non-reactive for calretinin and inhibin A. Besides, staining for SDHB shows intact cytoplasmic expression and the Ki-67 labeling index is 3. Based on the diagnostic algorithm for oncocytic adrenocortical tumors which included three major criteria and four minor criteria, the tumor is classified as oncocytic adrenocortical tumor of uncertain malignant potential because of match to one of four minor criteria, large size (>100 mm) and/or high weight (>200 g).

The patient had an uneventful recovery and was discharged 6 days after surgery under stable condition. She was under regular follow-up including physical examination, biochemistry and imaging study (CT or abdominal ultrasound). There was no evidence of recurrence at five years after surgery.

Conclusion:

The incidence of oncocytic adrenocortical tumor of uncertain malignant potential is very low. Most cases are non-functioning and usually are detected incidentally. Since the definite diagnosis can only be made histopathologiclly and adrenalectomy is the mainstay of therapy. Little is known about the long-term outcome of oncocytic adrenocortical tumors. Our case has been followed up for five years with no evidence disease. Based on the case report, we recommend interval image follow up is mandatory for this rare adrenal tumor.