Germ-cell tumours: SAQ

This newborn has the classic presentation of a sacrococcygeal teratoma, the commonest solid tumour of the newborn, and the task is to assess for the acute compromise, to confirm the diagnosis with the imaging and the serum markers, and to plan the surgery and the surveillance in a specialist paediatric surgical and oncology centre. [1]

Question 1 (10 marks)

Outline your immediate assessment and the diagnostic pathway for this two-day-old infant with a sacrococcygeal mass and a markedly elevated serum alpha-fetoprotein. [11]

A full-mark answer covers the recognition of the acute compromise, the imaging, the interpretation of the alpha-fetoprotein against the age, and the histological pathway that delivers the named diagnosis. [3]

Recognition and the first decision (2 marks). A sacrococcygeal mass in a newborn is a sacrococcygeal teratoma until the imaging proves otherwise. The first priority is to assess for the high-output cardiac failure and the cardiovascular compromise that a large and highly vascular tumour can produce through the vascular steal, because the unrecognised failure is the threat to the circulation. The neonatal team, the paediatric surgery and the oncology are alerted at once. [1]

Resuscitation (2 marks). The newborn with the large tumour and the cardiac compromise is admitted to the neonatal intensive care, with the cardiovascular support and the careful fluid management. The rupture of the tumour and the bleeding into the lesion are managed with the transfusion and the emergency surgery. The airway, the breathing and the circulation are secured before the definitive imaging. [11]

Diagnostic imaging (3 marks). The ultrasound confirms the solid mass and the relationship to the sacrum and the coccyx, and the magnetic resonance imaging is the standard that defines the internal and the external components, the Altman type, and the relationship to the rectum, the bladder and the sacral plexus. The computed tomography of the chest is added when the malignant component is suspected, to stage the metastatic disease. [11]

Serum markers and the age correction (3 marks). The serum alpha-fetoprotein, the beta-human chorionic gonadotropin and the lactate dehydrogenase are sent, and the markedly elevated alpha-fetoprotein in the two-day-old must be interpreted against the physiological neonatal elevation. The alpha-fetoprotein is very high at birth, in the tens of thousands of nanograms per millilitre, it falls with a half-life of about five to seven days, and it reaches the adult range by the age of eight to twelve months. A raised beta-human chorionic gonadotropin would be significant, as it is not physiologically elevated. The marker trend is followed serially. [3]

Question 2 (10 marks)

Discuss the surgical and oncological management of the sacrococcygeal teratoma, including the principle of the coccygectomy, the management of the malignant component, and the surveillance of the recurrence and the malignant transformation. [2]

A full-mark answer reproduces the surgical principle, the role of the chemotherapy, and the surveillance that catches the recurrence and the transformation early. [11]

The coccygectomy (4 marks). The complete surgical resection is the foundation of the cure, and the complete removal of the coccyx, the coccygectomy, is mandatory at the primary resection and not optional. The retained coccyx harbours the residual germ cell elements that regrow the tumour, and the failure to remove the coccyx is the single strongest predictor of the local recurrence and the subsequent malignant transformation into the yolk sac tumour. The Altman type guides the surgical approach, with the type four presacral lesion demanding the meticulous pre-sacral dissection. [11]

The benign versus the malignant disease (2 marks). The mature teratoma is the benign lesion cured by the complete resection with the coccygectomy, and it needs no chemotherapy. The malignant component, most often the yolk sac tumour, declares with the alpha-fetoprotein that fails to fall appropriately against the age, and it is managed with the platinum-based PEB chemotherapy of the cisplatin, the etoposide and the bleomycin in addition to the surgery. [3]

The chemotherapy (2 marks). The intermediate and the higher-stage malignant tumour receives the PEB regimen in three to four cycles, with the carboplatin substituted in the low-risk regimen to reduce the cisplatin ototoxicity and nephrotoxicity. The marker fall with each cycle tracks the response, and the bleomycin pulmonary fibrosis and the cisplatin ototoxicity are the toxicities that drive the surveillance. [4]

The surveillance (2 marks). The recurrence and the malignant transformation are the long-term pitfalls that the surveillance is built to catch. The alpha-fetoprotein is monitored serially, and the magnetic resonance imaging is performed at the intervals, because the recurrence most often declares at the primary site and the malignant transformation into the yolk sac tumour is the feared late event. The audiology, the renal function and the pulmonary function are monitored in the child who received the chemotherapy. [11]