A 1-month old infant undergoes resection of a predominantly cystic sacrococcygeal mass along with the coccyx, following MRI diagnosis of a suspected mature germ cell tumor (MRI demonstrates multilobular cystic mass (arrows) consistent with mature cystic teratoma). The pathology on the resected specimen was “mature cystic teratoma containing fat and respiratory epithelium, completely excised”. The serum alpha fetoprotein (AFP) measured immediately prior to surgery was 420ug/l, which is within the normal range for a 1-month old. Postoperative followup during the first year should be:

 

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[size=20px]A AFP, clinical examination, US at 6 months of age

 

B 3-monthly AFP, clinical examination, US

 

C AFP, MRI at 1 year of age

 

D No scheduled follow up required

 

E AFP, clinical examination, US at 1 year of age [/size]

B

B

B

B

B

The most reliable answer is B.

B

B

B

Option B

B

B

B

B

correct answer

B 3-monthly AFP, clinical examination, US DISCUSSION

 

There are a number of factors which contribute to germ cell tumor (GCT) recurrence after resection including tumor histology, incomplete resection/tumor rupture, and failure to remove the coccyx.

 

Serum AFP is a well-established marker of malignancy, and its interpretation during the first few months of life when it is known to be physiologically elevated, in a patient who has undergone GCT resection can be confusing. Another poorly understood, but well documented phenomenon is the potential for a resected benign (mature or immature) GCT to have a malignant recurrence. A recently published meta-analysis of 22 studies identified a total of 999 patients with mature histology following SCT resection, from which there were 102 recurrences (10.2%). Of these, 57 (56%) proved to be malignant recurrences, and almost all were yolk sac tumors. The association of immature teratomas with malignant recurrence is even higher. This presumes the existence of a nest of malignant cells in a resected teratoma that is missed at initial pathologic review, or residual yolk sac tumor or residual benign teratoma that undergoes malignant transformation.

 

Following GCT resection in any newborn or infant, serum AFP and clinical (digital rectal) examination should be 3 monthly, until 3 years of age. Regular primary site imaging (usually ultrasound, but occasionally MRI or CT scan) is also recommended.

 

 

 

Recommended followup schedule following infant germ cell tumor resection