International Medical Journal Vol. 27, No. 4, pp. 391 - 392 , August 2020

INTERNAL MEDICINE

Extragonadal Mixed Germ Cell Tumour in Anterior Mediastinal

Allen Shiun Chat Chai, Nani Draman, Siti Suhaila Mohd Yusoff

ABSTRACTIntroduction: Presentations of anterior mediastinal mass ranges from asymptomatic to symptomatic with respiratory symp-

tom and from benign to malignant. Frontline health workers have high chance to detect these since chest radiography is avail-able at primary care level. However, early detection remains difficult and consequently poor prognosis.

Objective: To describe a case of extragonadal mixed germ cell tumour in anterior mediastinum in a young man and discuss the difficulties toward early detection of mediastinum mass.

Method: A case of mixed germ cell tumour of anterior mediastinum is described, followed by discussion on challenges with early detection.

Results: Patient with anterior mediastinal malignant tumour can remain asymptomatic despite having large mass. There is no effective screening method for it at the moment, such as yearly chest imaging or periodic tumour markers testing.

Conclusion: Further research is needed to explore the strategy toward early detection of anterior mediastinal mass.

KEY WORDSAnterior Mediastinal mass, mediastinal mass, extragonadal germ cell tumour, primary care

Received on September 22, 2019 and accepted on November 1, 2019Department of Family Medicine, School of Medical Sciences, Universiti Sains Malaysia16150 Kubang Kerian, Kelantan, MalaysiaCorrespondence to: Nani Draman(e-mail: drnani@usm.my)

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INTRODUCTION

Extragonadal germ cell tumours (EGGCTs) are neoplasms com-posed of two or more types of germ cell without the presence of primary gonadal tumour. It represents 5-10% of total germ cell tumour (GCTs), with an incidence around 1 in 1,000 000 population1).

Mediastinum is the common site for EGGCTs. Two thirds of medi-astinal mass are malignant in nature, and anterior mediastinum consists 50% of the total mediastinal mass2). Symptomatic cases are more fre-quent in malignant masses and located in anterior mediastinum3).

We present this case report and discuss the differential diagnoses and problems with early detection.

MATERIALS AND METHODS

A 23 years old, final year dental student, healthy with no history of known medical illness, presented to emergency department with first episode, acute left sided severe chest pain with a pain score of 8/10 and relieved by leaning forward. Otherwise, he did not complain of short-ness of breath, reduced effort tolerance, cough, or other constitutional symptoms. There is no personal history and family history of malignan-cy. He neither smokes nor drinks. His medical examination done 4 years ago, prior entering dentistry school, including chest X-ray were normal.

During examination, he was in sitting and leaning forward position to alleviate his pain. Apart from tachycardia and in pain, other vital signs were within normal range. Respiratory examination revealed tra-chea deviation to the right side and physical examination suggestive of left lower zone collapse. Examinations of other system were unremark-able.

Electrocardiogram showed sinus tachycardia with no ischemic

changes. Chest X-ray showed widened mediastinal region with left lung collapse (Figure 1). CT-thorax revealed left anterior mediastinum mass, measuring 8.5 cm X 8.1 cm X 7.5 cm. There was obliteration of fat plane between the mass and the left ventricle and left pulmonary artery (Figure 2). Serum lactate dehydrogenase (LDH) showed 458 U/L. Tumour markers showed alpha feto-protein (AFP): 123.52 ng/ml and beta human chorionic gonadotropin (β-hCG) level: 47 iU/L. CT-guided biopsy revealed germinoma with teratomatous element.

His condition deteriorated and succumbed one month after diagno-sis was made.

RESULT AND DISCUSSION

Anterior mediastinum is the most common site for EGGCT, fol-lowed by retroperitoneum (30-40%)4). Apart from germ cell tumour, oth-ers differential diagnoses, can be recalled with the mnemonic T's, name-ly Thymus (Thymoma), Thyroid (ectopic thyroid masses), Thoracic aorta and Terrible lymphoma.

The variety presentations of EGGCT make early detection difficult. In mediastinum, patients can remain asymptomatic until the late stage of the illness, as seen in this case report. Similar to EGGCT in other site, its presentation ranges from asymptomatic to non-specific abdominal pain and even unexpected sudden death due to brain metastasis5).

The main obstacle toward early detection is this particular patient is he remains asymptomatic despite having a large mass (8.5 cm) in the mediastinum. It is probably because mediastinum provides potential space for tumour to grow before causing compressive symptoms. To the best of our best knowledge, the duration from asymptomatic to symp-tomatic state is unknown. Apart from respiratory symptoms, others being reported symptoms in the literature, such as fever, weight loss and venous thrombosis6) which were not presented in our case.

C 2020 Japan Health Sciences University & Japan International Cultural Exchange Foundation

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Few tumour markers and blood tests aid in diagnosis. Elevation of AFP suggests germ cell tumour; elevation of β-hCG suggests choriocar-cinoma; while elevation of both, as shown in this case suggest mixed germ cell tumour. Elevation of LDH level is non-specific as it elevates in other diseases7). Tumour markers, although help in the diagnosis and recurrence detection during follow up, are not the recommended tools of screening.

Imaging would probably enable detection of the mediastinum tumour at an early stage. In this case, his current chest radiography showed a huge mass, which was not seen in the chest radiography taken 4 years ago. This leads to our enquiry whether yearly chest radiography could have changed his outcome.

To our best knowledge, the prevalence of incidental finding of ante-rior mediastinal mass via chest radiography is not known. In the Framingham Heart Study, the prevalence of anterior mediastinal mass is 0.9%. via CT scan8). However, further studies are needed to explore the usefulness, cost-effectiveness and mortality reduction with plan chest radiography or CT-thorax as a screening modality for mediastinum masses.

CONCLUSION

Early detection of anterior mediastinum mass remains a great chal-lenge. The current imaging modalities, such as chest radiography and CT scan are helpful. However, further studies are needed to explore new strategies.

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Figure 1. Chest radiograph showed homogenous opacity lesion at left middle zone. The lateral boarder of the lesion appears contiguous with left heart boarder inferiorly suggestive of mediastinal in origin

Figure 2. Heterogenous hypodense soft tissue lesion at the left anterior mediastinal region with left pleural effusion.