Case report and review of literature: immature teratoma with islets of a yolk-sac tumour: could it be omitted for years?

Keywords:

• Immature teratoma
• malignant ovarian germ cell tumour
• yolk-sac tumour
• endodermal sinus tumour
• surgery
• fertility-sparing treatment

Introduction

Among the ovarian germ cell neoplasms, the teratomas are the most common ones, comprising about 10–20% of all ovarian malignancies in women younger than 20 years (Iavazzo et al. 2017). Mixed malignant germ cell tumours represent a combination of two or more malignant components, observed in about 8% of all cases of malignant ovarian germ cell tumours (MOGCT). The most common combination is that of dysgerminoma with the yolk sac tumour (YST) (Rana et al. 2016). The YST component indicates higher malignant potential of the lesion, mandating more precautious therapeutical approach. Immature teratomas (IMTs) usually affect girls during the first two decades of life (Der and Seidu 2019). The most common symptoms are unspecific: pain, abdominal distension and masses (Wang et al. 2017). On radiographs, magnetic resonance imaging (MRI) and ultrasound scans, IMTs are typically larger (14–25 cm) than mature cystic teratomas (usually up to 7, 5 cm). In addition, they may have a prominent solid component in the cystic elements (Nishida et al. 2014).

Case report

A 24 years old, G0P0 woman, went for her first contraceptive counselling to her primary gynaecologist. On a pelvic examination, a palpable mass in her abdomen was detected, so she was referred to ultrasonography. The sonography revealed mixed mass that fills the pelvis and extends high to upper abdomen. The patient was referred to abdominal multislice computed tomography (MSCT) which demonstrated mixed density left ovarian neoplasm, with clear demarcation and no suspicious abdominal lymph nodes. Tumour markers CA 125 and AFP were in reference range. On presumptive clinical diagnosis of left-sided ovarian teratoma, the extended medial incision was made and left-side adnexectomy was performed. The tumour was partly cystic, partly solid, consisted of fat and soft tissue and abundant calcifications, mostly in the cranial parts of the tumour capsule. The contralateral ovary and the uterus were preserved. A complex adnexal tumour, 33 × 23 × 19 cm in size and 7162 g in weight was removed. There was no sign of infiltrative growth, nor visible or palpable suspicious lymph nodes. Peritoneal washings were performed and sent to cytology as well. Pathohistological diagnosis was of high grade IMTs (5th edition of WHO Classification 2020), with isolated islets of YST. Peritoneal washings revealed no atypical cells. Additional immunohistochemically reactions for SALL-4 and Gylpican-3 were performed. While SALL-4 exhibited marked nuclear positivity in questionable areas of YST, the Glypican-3 reaction was granular and weakly positive in single cell nests. The diagnosis of a mixed MOGCT with a predominantly IMTs and only a small amount of multifocal YST was established. The recommendation was to perform the second, laparoscopic surgery which should include infragastric omentectomy, peritoneal biopsies and ipsilateral pelvic lymphadenectomy. All the samples were free of tumour cells on subsequent histology. According to TNM Classification, the final tumour stage was pT1a N0 (0/1) L0 V0 Pn0 R0. After the surgery and analyses, the patient was advised to have regular three month check up with her gynaecologist and bi-annual abdominal MSCT evaluation. No chemotherapy was suggested due to patient’s uncompleted reproductive wishes. The patient recovered well and follows the advised regimen, five years so far without recurrence of the disease.

Discussion

Patients who do not present with pain, and experience steadier growth of a tumour, as it was the case with our patient, represent a more challenging diagnostic group. It has been suggested that alpha feto-protein (AFP) can be applied as a feasible tumour marker for the YST component of the tumour, because its level was elevated in >90% of YSTs (Chen et al. 2019). However, in our patient, the amount of secreted AFP was in normal range despite clear evidence of YST islets on histology (Perry et al. 2020). Combination of predominantly IMTs with islets of an YST, as it was documented in our patient, is extremely rare. Until now we did not find any published report on this combination. In literature, there are several reports about patients with MOGCT comprised with IMT, YST and embryonal carcinoma lines, occasionally referred to as the ‘polyembryoma’ (Ulbright 2005). Generally, it is recommended for the IMT patients of stage I and G1 to be treated with surgery alone, because the prognosis is good (RCOG 2016). The primary goal to be as conservative as possible is usually achieved with unilateral oophorectomy, peritoneal washing, omental biopsy, and selective removal of enlarged lymph nodes. Normal contralateral ovary should not be biopsied. Systematic lymphadenectomy is discouraged, while it did not provide better outcomes (RCOG 2016). A combination of fertility-sparing surgical strategies and chemotherapy (BEP protocol) has been proven to preserve fertility, with a 94% 5-year survival rate (Cerovac et al. 2018). The most frequent sites of recurrence are the peritoneal cavity, the retroperitoneal lymph nodes and lungs. Therefore, the long-term follow-up strategy should include assessment of tumour markers at each visit. CT imaging of the pelvis, abdomen, and chest (if abnormal at presentation) should be performed 3 months after completion of chemotherapy and then as clinically indicated (RCOG 2016).

Gynaecological cancer is a very stressful experience for women and treatments can compromise fertility and sexual function. Quality of life and psychological wellbeing of patients are highly weakened after a cancer diagnosis. Fertility preservation techniques in women with MOGCT can play an important role in improving the quality of life of these patients. Long-term psycho-oncological support is strongly recommended especially in young patients (Laganà et al. 2017, Dessole et al. 2018, La Rosa et al. 2020).

Clinical as well as diagnostic pathohistological implications of our study refer to thinking about rare pathohistological forms of MOGCT and their combinations during clinical treatment, operative procedure, and pathohistological analysis. It is also important to apply basic oncological principles for fertility sparing surgery. Negative tumour marker values do not exclude the existence of MOGCT. Future studies about monitoring of survival and disease recurrence are necessary, as well as analysis of prevalence of the pathohistological entity described for the first time so far.

Our first case report to date, to the best of our knowledge, predominantly IMTs with islets of an YST is an example of successful fertility-sparing treatment in its early stages. However, fertility preservation in the cancer setting, known as oncofertility, became one of the hot topics in young patients with cancer.

Ethical approval

These is case report, for which there is no requirement of our institution to seek permission of the Ethics Committee to publish a paper. We obtained a required patient’s permission.

Consent form

The patient signed an informed consent statement.

Disclosure statement

Authors declare that there is no conflict of interest related to this article. All authors made a substantial contribution to the concept and design, acquisition, analysis and interpretation of data.

Additional information

Funding

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