CASE 11546 Published on 27.01.2014
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Mature benign cystic teratoma of the right adrenal gland in a 21-year-old female patient: A case report

Section

Uroradiology & genital male imaging

Case Type

Clinical Cases

Authors

Sally Emad-Eldin, Youstina G. Shokry, Ahmed Zein, Sameh A. Z. Hanna

Department of Diagnostic and Intervention Radiology,
Cairo University Hospitals,
Kasr Al-Ainy,
Cairo, Egypt.
Connected authors
Patient

21 years, female

Categories
Area of Interest Abdomen ; Imaging Technique CT
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Clinical History
A 21-year-old female patient presented with abdominal pain of 6 months duration. Physical examination revealed a palpable, non-tender right flank mass. All laboratory investigations were unremarkable.
Imaging Findings
Abdominal CT examination with IV contrast showed a large right side retroperitoneal mass lesion, measuring about 8x10x12 cm in its maximum diameters. The mass appeared heterogeneous with mixed soft tissue (arrow head) and fat content (arrow). Tiny calcific foci were also seen at the wall of the lesion. The right adrenal gland was indistinct. The mass was displacing the liver, right kidney, renal vein and IVC with no signs of infiltration. (Fig.1)

Upon surgical exploration a freely mobile tumour originating from the right adrenal gland was identified. The patient underwent complete surgical resection of the lesion. Grossly the lesion had well-circumscribed borders and rubbery consistency. The cut-section was soft and yellowish with areas of cystification filled with yellowish pasty material. (Fig.2)
Microscopically the cyst walls were lined with keratinzed squmaous epithelium, it shows lobules of mature adipocytes entangling bony trabeculae, blood vessels, mature glial tissue. No evidence of malignancy was identified.
Discussion
The adrenal gland as the origin of a teratoma is extremely rare, only few cases are reported [1-4]. According to degree of maturation, teratomas are classified as mature, immature and malignant teratomas [5]. A mature teratoma is an adult-type tumour consisting of differentiated elements [6]. Most mature teratomas are cystic, and therefore called dermoid cysts [2]. They are usually benign, although they have potential for malignant transformation [3].
Retroperitoneal teratomas have bimodal peak in incidence (first 6 months of life and early adulthood) [5]. The retroperitoneum provides a large space to grow, so tumours are large at the time of presentation. They may cause abdominal or back pain, or may be asymptomatic and discovered incidentally. Cystic teratomas may rupture and cause sudden onset of abdominal pain, ascites, and peritonitis [7].
The morphologic features of mature teratoma extend from predominantly cystic to completely solid [8].The characteristic imaging findings are a well-defined, fat-containing mass with heterogeneous density/signal, fat-fluid level or calcification [9]. Calcifications present as punctate, shard-like or linear-strand high densities in mature teratomas. If the attenuation of calcification is higher than cortical bone, this sign strongly suggests that teeth are contained in the lesion [9].
CT and MRI can reliably detect fat. [9] CT better distinguishes between fat and calcified masses [10], whereas MRI offers better soft tissue resolution, identification of benign and malignant neoplastic features, and superior tumour staging [11]. The diagnosis is often made on the basis of imaging [5]. However, a definitive diagnosis requires histopathology [12].
Differentiation of a retroperitoneal teratoma in the para-adrenal area from a true adrenal teratoma is tricky. Generally, the exact location is difficult to define [13]. In our case, because the normal adrenal gland could not be recognized, the mass was thought to be a neoplasm arising from adrenal gland. Based on its characteristic CT findings, a diagnosis of teratoma was considered.
As fat-contained mass arising from the adrenals, myelolipoma must be considered firstly in the differential diagnosis. Other tumours as angiomyolipoma, lipoma and liposarcoma are very rare [9]. Compared to them teratomas are more heterogeneous and calcification is more common [2, 14].
Complete surgical resection and close follow-up are the recommended therapy and required for definitive diagnosis [5, 15]. Prognosis is excellent after complete excision with 100% overall 5-year survival rate [16].
Primary mature cystic teratoma of the adrenal gland can present as a large retroperitoneal mass, with the characteristic imaging findings of complex mass with fat and calcification.
Differential Diagnosis List
Mature benign cystic teratoma of the right adrenal gland
Adrenal myelolipoma
Retroperitoneal lipoma
Retroperitoneal liposarcoma
Final Diagnosis
Mature benign cystic teratoma of the right adrenal gland
Case information
URL: https://www.eurorad.org/case/11546
DOI: 10.1594/EURORAD/CASE.11546
ISSN: 1563-4086
Figure 1

Abdominal CT with IV contrast reconstructed in coronal & sagittal planes.

Abdominal CT with IV contrast reconstructed in coronal & sagittal planes.
There is a large right-side retroperitoneal mass. The mass appears heterogeneous with mixed soft tissue (arrow head) and fat content (arrow). Tiny calcific foci are seen at the wall of the lesion.
Abdominal CT with IV contrast reconstructed in coronal & sagittal planes.
The right adrenal gland is indistinct.
Abdominal CT with IV contrast reconstructed in coronal & sagittal planes.
The mass is displacing the right kidney, IVC and renal vein with no signs of infiltration.
Figure 2

Photograph of the gross surgical specimen of the lesion

Photograph of the gross surgical specimen of the lesion
Photograph of the gross surgical specimen of the lesion opened in the operating room and demonstrating soft and yellowish cut section of the lesion with the yellowish pasty material that filled the lesion.