Figure 1
CT of the liver
CT of the liver showing a rather rounded well-circumscribed hepatic focal lesion of fat attenuation value.
Unusual case of fatty liver metastasis from a pathologically proven immature ovarian teratoma
SectionAbdominal imaging
Case TypeClinical Cases
AuthorsIslam A. Shehata, Shaima Fattouh, Awad A. Ahmed, Haney Sami
Connected authors
21 years, female
Clinical History
A 21-year-old female patient presented with vague lower abdominal pain and frequency of micturition. No other relevant symptoms. Laboratory findings revealed an elevated Alfa-feto protein level. Abdominal and pelvic CT was requested to investigate the cause of the abdominal pain.
Imaging Findings
Abdominal CT revealed a well-circumscribed hypodense lesion of fat attenuation value in the right hepatic lobe (segment VIII). The lesion measured about 4 x 3 cm in axial dimensions and did not show significant contrast enhancement (Fig. 1). Careful examination of the hepatic focal lesion revealed a peripheral minute calcification (Fig. 2). No other hepatic lesions were detected.
Pelvic CT revealed a left para-uterine complex cystic mass lesion, likely of adnexal origin (Fig. 3). The lesion measured about 8 x 7 cm along its maximum axial dimensions. The lesion showed hypodense areas of fat attenuation value and minute mural calcification (Fig. 4). The lesion exerted mass effect in the form of compression and right-sided displacement of the urinary bladder as well as displacement of the pelvic bowel loops. No CT evidence of direct infiltration of any of the pelvic organs.
Metastatic work-up revealed additional metastatic pulmonary nodules (not shown).
Pelvic CT revealed a left para-uterine complex cystic mass lesion, likely of adnexal origin (Fig. 3). The lesion measured about 8 x 7 cm along its maximum axial dimensions. The lesion showed hypodense areas of fat attenuation value and minute mural calcification (Fig. 4). The lesion exerted mass effect in the form of compression and right-sided displacement of the urinary bladder as well as displacement of the pelvic bowel loops. No CT evidence of direct infiltration of any of the pelvic organs.
Metastatic work-up revealed additional metastatic pulmonary nodules (not shown).
Discussion
Background:
Ovarian tumours are generally classified into epithelial tumours, germ cell tumours, sex cord-stromal tumours and metastatic tumours [1]. Ovarian teratomas are the most common germ cell tumours. They contain mature or immature tissues of germ cell origin [2]. Mature cystic teratomas, also known as dermoid cyst, are the most common ovarian neoplasm removed at surgery [2]. On the other hand, immature teratomas are considered a rare entity, accounting for less than 1 % of ovarian teratomas. They demonstrate malignant behaviour [2].
Clinical perspective:
Most ovarian teratomas are asymptomatic. Some patients may experience vague abdominal pain or non-specific symptoms. Teratomas are common among young age groups (mean age 30 years) [3].
Imaging perspective:
The presence of hypodense areas of fat attenuation value with or without calcification is virtually diagnostic of teratomas on CT [2]. Mature cystic teratomas are dominantly cystic and commonly unilocular. They show an internal projection called Rokitansky nodule which may contain hair, bone or even teeth [4, 5]. Immature teratomas are complex cystic masses with more solid components and smaller fat foci that may be difficult to distinguish. Calcifications are more scattered and patients are usually younger (usually during the first two decades of life) [2]. It is noteworthy to mention that ultrasound is an ideal imaging tool for initial investigation of pelvic masses in young female patients. Ultrasound is non-ionizing and readily available. The multi-cystic nature of the complex pelvic mass is well-depicted [6]. Fat loculi appear as echogenic areas, and foci of calcification can be seen as more echogenic spots with possible acoustic shadowing.
Outcome:
This patient had surgical excision of the malignant teratoma and received chemotherapy. Histopathology confirmed the diagnosis of malignant ovarian teratoma.
Take home message:
The finding of elevated Alfa-feto protein +/- Beta human chorionic gonadotropin in a young female patient with adnexal mass is virtually diagnostic of ovarian malignant germ cell tumour [6]. These tumour markers should be measured in all young ladies presenting with pelvic masses [6]. Ovarian malignant teratoma is a rare entity. Malignant teratomas have a clinical malignant behaviour and have less fat and more solid component with more scattered calcification than benign cystic teratomas (dermoid cyst). While metastasis usually shows histo-pathological differentiation similar to that of the primary tumour, this case is a good example of how a metastatic liver deposit showed similar imaging criteria as the primary ovarian tumour; containing fat and calcification as well.
Ovarian tumours are generally classified into epithelial tumours, germ cell tumours, sex cord-stromal tumours and metastatic tumours [1]. Ovarian teratomas are the most common germ cell tumours. They contain mature or immature tissues of germ cell origin [2]. Mature cystic teratomas, also known as dermoid cyst, are the most common ovarian neoplasm removed at surgery [2]. On the other hand, immature teratomas are considered a rare entity, accounting for less than 1 % of ovarian teratomas. They demonstrate malignant behaviour [2].
Clinical perspective:
Most ovarian teratomas are asymptomatic. Some patients may experience vague abdominal pain or non-specific symptoms. Teratomas are common among young age groups (mean age 30 years) [3].
Imaging perspective:
The presence of hypodense areas of fat attenuation value with or without calcification is virtually diagnostic of teratomas on CT [2]. Mature cystic teratomas are dominantly cystic and commonly unilocular. They show an internal projection called Rokitansky nodule which may contain hair, bone or even teeth [4, 5]. Immature teratomas are complex cystic masses with more solid components and smaller fat foci that may be difficult to distinguish. Calcifications are more scattered and patients are usually younger (usually during the first two decades of life) [2]. It is noteworthy to mention that ultrasound is an ideal imaging tool for initial investigation of pelvic masses in young female patients. Ultrasound is non-ionizing and readily available. The multi-cystic nature of the complex pelvic mass is well-depicted [6]. Fat loculi appear as echogenic areas, and foci of calcification can be seen as more echogenic spots with possible acoustic shadowing.
Outcome:
This patient had surgical excision of the malignant teratoma and received chemotherapy. Histopathology confirmed the diagnosis of malignant ovarian teratoma.
Take home message:
The finding of elevated Alfa-feto protein +/- Beta human chorionic gonadotropin in a young female patient with adnexal mass is virtually diagnostic of ovarian malignant germ cell tumour [6]. These tumour markers should be measured in all young ladies presenting with pelvic masses [6]. Ovarian malignant teratoma is a rare entity. Malignant teratomas have a clinical malignant behaviour and have less fat and more solid component with more scattered calcification than benign cystic teratomas (dermoid cyst). While metastasis usually shows histo-pathological differentiation similar to that of the primary tumour, this case is a good example of how a metastatic liver deposit showed similar imaging criteria as the primary ovarian tumour; containing fat and calcification as well.
Differential Diagnosis List
Immature ovarian teratoma with fatty hepatic metastasis.
Lipoma of the liver
Fatty hamartoma of the liver (e.g: with tuberous sclerosis)
Final Diagnosis
Immature ovarian teratoma with fatty hepatic metastasis.
References
[1] Koonings PP, Campbell K, Mishell DR Jr, Grimes DA. (1989) Relative frequency of primary ovarian neoplasms: a 10-year review. Obstet Gynecol 74(6):921-6. (PMID: 2685680)
[2] Outwater EK, Siegelman ES, Hunt JL. (2001) Ovarian teratomas: tumor types and imaging characteristics. Radiographics 21(2):475-90 (PMID: 11259710)
[3] Comerci JT Jr, Licciardi F, Bergh PA, Gregori C, Breen JL. (1994) Mature cystic teratoma: a clinicopathologic evaluation of 517 cases and review of the literature. Obstet Gynecol 84(1):22-8 (PMID: 8008317)
[4] Caruso PA, Marsh MR, Minkowitz S, Karten G. (1971) An intense clinicopathologic study of 305 teratomas of the ovary. Cancer 27(2):343-8 (PMID: 5100397)
[5] Matz MH. (1961) Benign cystic teratomas of the ovary. A review. Obstet Gynecol Surv 16:591-605. (PMID: 14471483)
[6] Shaaban AM1, Rezvani M, Elsayes KM, et al. (2014) Ovarian malignant germ cell tumors: cellular classification and clinical and imaging features. Radiographics 34(3):777-801 (PMID: 24819795)
Case information
| URL: | https://www.eurorad.org/case/11975 |
| DOI: | 10.1594/EURORAD/CASE.11975 |
| ISSN: | 1563-4086 |
Figure 2
CT of the liver
CT of the liver showing a minute hyperdense calcific focus (arrow) at the periphery of the hepatic focal lesion.
Figure 3
Coronal CT of the abdomen and pelvis
Coronal reformatted images of the abdomen and pelvis showing a complex cystic left pelvic mass lesion (arrows) that is seen compressing and displacing the urinary bladder (UB) to the right.
Figure 4
Coronal CT of the abdomen and pelvis
The complex cystic pelvic mass lesion showed hypodense foci of fat attenuation value (white arrows) as well as a minute peripheral calcific focus (red arrow).
CT of the liver
CT of the liver showing a rather rounded well-circumscribed hepatic focal lesion of fat attenuation value.
Department of Diagnostic Radiology, Cairo University, Egypt
Department of Diagnostic Radiology, Cairo University, Egypt
CT of the liver
CT of the liver showing a minute hyperdense calcific focus (arrow) at the periphery of the hepatic focal lesion.
Department of Diagnostic Radiology, Cairo University, Egypt
Department of Diagnostic Radiology, Cairo University, Egypt
Coronal CT of the abdomen and pelvis
Coronal reformatted images of the abdomen and pelvis showing a complex cystic left pelvic mass lesion (arrows) that is seen compressing and displacing the urinary bladder (UB) to the right.
Department of Diagnostic Radiology, Cairo University, Egypt.
Department of Diagnostic Radiology, Cairo University, Egypt.
Coronal CT of the abdomen and pelvis
The complex cystic pelvic mass lesion showed hypodense foci of fat attenuation value (white arrows) as well as a minute peripheral calcific focus (red arrow).
Department of Diagnostic radiology, Cairo University, Egypt
Department of Diagnostic radiology, Cairo University, Egypt