CASE 12615 Published on 20.10.2015

Ovarian dysgerminoma with torsion

Section

Genital (female) imaging

Case Type

Clinical Cases

Authors

Parveen Sulthana M, Saravana Kumar S, Malathi V, Sekhar KS

Billroth hospitals
Department of Radiology
Lakshmi talkies road
Shenoy nagar
Chennai-600 030, India
Email:drspjkmc@gmail.com

Patient

21 years, female

Categories

Area of Interest Genital / Reproductive system female ; Imaging Technique MR

Procedure Diagnostic procedure ; Special Focus Neoplasia ;

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Clinical History

A 21-year-old female patient presented with pain in the right iliac fossa for the past week. She had regular menstrual periods. No history of vomiting.

Imaging Findings

A large lobulated T2W heterogeneously intermediate to hyperintense and T1W mildly hyperintense mass lesion was noted arising from the right ovary, extending up to the mid-abdomen on the right side. The lesion showed areas of restricted diffusion. Twisting of the right ovarian pedicle along with the right fallopian tube was seen. The medial component of the lesion showed marked T2W hyperintense signal with small peripherally placed follicles, likely to represent massive ovarian oedema. Mild ascites was noted. Based on the imaging appearance and patient's age, the possibility of a malignant germ cell tumour with torsion and massive ovarian oedema was suggested.

Discussion

The term 'dysgerminoma', first coined by Meyer in 1931 [1], describes a rare malignant germ cell tumour of the ovary, predominantly occurring in young women. Dysgerminomas comprise 0.5 to 2 % of all malignant ovarian tumours and pathologically they are composed of cells that are similar to primordial germ cells with no potential for further differentiation [2]. They are bilateral in 15% of cases. It is one of the most common tumours associated with pregnancy.
Elevated serum LDH levels are commonly seen with elevated HCG in 5% of cases. Clinically it presents as abdominal mass with or without abdominal pain.
The characteristic findings on MRI are multilobulated solid masses with prominent fibrovascular septa. Areas of necrosis, haemorrhage and speckled calcification can be present [3, 4].
Ovarian torsion occurs when there is twisting of the ovary and its vascular pedicle on its suspensory ligament, initially leading to venous and lymphatic obstruction, with subsequent ovarian oedema and enlargement. Later the arterial circulation is compromised, resulting in thrombosis, leading on to ischaemia and haemorrhagic infarction [5]. The common predisposing factors include physiologic cysts, endometriomas, benign or malignant neoplasms. MRI reveals an enlarged ovary with a central afollicular stroma and peripherally displaced follicles. Other reported features on imaging are ascites, deviation of the uterus to the side of the twist, engorged vessels on the twisted side, and thickening of fallopian tube [5, 6, 7]. Twisting of the vascular pedicle is a definitive sign but may be difficult to detect on MRI.
Massive ovarian oedema first described by Kalstone in 1969 is defined as an accumulation of oedema fluid within the ovarian stroma separating normal follicular structures. It can be primary or secondary. Secondary massive ovarian oedema occurs with an abnormal ovary associated with a mass [8].
Complications include torsion of the tumour and rupture. Many case reports of torsion of dysgerminoma of the ovary have been described in the paediatric age group in the literature with very few case reports in adults.
The patient underwent surgery and the histopathology report confirmed dysgerminoma. Our case illustrates the characteristic imaging findings of this tumour.

Differential Diagnosis List

Malignant germ cell tumour (dysgerminoma) from right ovary with torsion

Endodermal sinus tumour

Granulosa cell tumor

Final Diagnosis

Malignant germ cell tumour (dysgerminoma) from right ovary with torsion

References

[1] Meyer R (1931) The pathology of some special ovarian tumors and their relation to sex characteristics. Am J ObstetGynecol 22:697–713

[2] Lazebnik N, Balog A, Bennett S, Redline R, Liu J. (2009) Ovarian dysgerminoma: a challenging clinical and sonographic diagnosis. J Ultrasound Med Oct;28(10):1409-15 (PMID: 19778893)

[3] Jung SE, Lee JM, Rha SE, Byun JY, Jung JI, Hahn ST (2002) CT and MR imaging of ovarian tumors with emphasis on differential diagnosis. Radiographics Nov-Dec;22(6):1305-25 (PMID: 12432104)

[4] Tanaka YO, Kurosaki Y, Nishida M, et al (1994) Ovarian dysgerminoma: MR and CT appearance. J Comput Assist Tomogr 18:443–448 (PMID: 8188914)

[5] Duigenan S, Oliva E, Lee SI (2012) Ovarian torsion: diagnostic features on CT and MRI with pathologic correlation. AJR Am J Roentgenol Feb;198(2):W122-31 (PMID: 22268201)

[6] Chang HC, Bhatt S, Dogra VS. (2008) Pearls and pitfalls in diagnosis of ovarian torsion. Radiographics Sep-Oct;28(5):1355-68 (PMID: 18794312)

[7] Rha SE, Byun JY, Jung SE, Jung JI, Choi BG, Kim BS, Kim H, Lee JM. (2002) CT and MR imaging features of adnexal torsion. Radiographics Mar-Apr;22(2):283-94 (PMID: 11896219)

[8] Praveen R, Pallavi V, Rajashekar K, Usha A, Umadevi K, Bafna U. (2013) A clinical update on massive ovarian oedema - a pseudotumour?. Ecancermedicalscience May 14;7:318 (PMID: 23717339)

Case information

URL:	https://www.eurorad.org/case/12615
DOI:	10.1594/EURORAD/CASE.12615
ISSN:	1563-4086

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Sagittal T2W MRI

Sagittal T2W MRI shows a large mild heterogenously intermediate signal intensity abdomino-pelvic mass lesion with lobulated margins and few irregular T2W hyperintense areas within.

Sagittal T2W MRI shows an enlarged ovary (*) with marked hyperintense signal of the stroma and peripherally placed follicles.

Figure 2

Axial T2W MRI

Axial T2W MR image showing a lobulated mild hyperintense mass lesion.

Axial T2W MR image showing twisting (white arrow) of the right ovarian vascular pedicle.

Figure 3

Diffusion-weighted MRI

Diffusion-weighted MR image showing areas of hyperintense signal within the mass lesion that showed hypointense signal on ADC in keeping with restricted diffusion.

ADC map showing hypointense signal of the lesion.

Figure 4

Cine axial MR images

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Axial cine MRI showing a large heterogeneous mass lesion in the right adnexa with twisting of the ovarian vascular pedicle.

Figure 5

Axial T2W MRI with and without fat sat

Markedly enlarged ovary with T2W hyperintense signal and peripherally placed follicles along the medial aspect of the lesion in keeping with massive ovarian oedema. * points to the enlarged ovary with oedema.

Figure 6

Coronal T2W MRI

Coronal T2W MR image showing the large heterogeneous signal intensity mass lesion with twisting (white arrow) of the ovarian vascular pedicle. Minimal free fluid is also noted.

Figure 7

Axial T1W MRI

Axial T1W MR image showing a lobulated hypointense mass lesion in the right lower abdomen. * points to the enlarged ovary along the medial aspect of the lesion.