Pineal tumour panel (CSF-HCG, CSF-AFP, CSF placental-ALP)

Background

The pineal gland is composed of pineal cells and neuroglial cells, both of which can form neoplasms in the pineal region, as well as residual germ cells from primordial neural crest cell migration and cells derived from nearby structures.

Because of the wide variety of tissues in the pineal region, a tremendous diversity of malignant and benign tumours can develop. Pineal neoplasms are predominantly a childhood malignancy representing 3%-11% of all paediatric brain tumours compared to <1% of brain tumours in adults. Pineal region masses can cause syndromes of mass effect, including headache, aqueductal stenosis, hydrocephalus, Parinaud syndrome, or compressive hypothalamic syndromes such as diabetes insipidus and slowed growth.

Pineal region tumours are presently classified into 5 categories: germ cell tumours, pineal parenchymal cell tumours, glial cell tumours, papillary tumours of the pineal region, and miscellaneous tumours and cysts. Germinoma is the most common pineal tumour, representing up to 50% of pineal tumours in Europe, the United States, and Japan.

Particular serum and CSF biomarkers in conjunction with clinical and radiographic evidence of a pineal region mass can inform the decision to undertake stereotactic biopsy or surgical excision or to proceed straight to medical treatment. Workup of a pineal mass presently entails imaging followed by serum and CSF laboratory workup for germ cell tumour markers alpha-fetoprotein, β-hCG, and placental alkaline phosphatase. Whilst these markers can be somewhat helpful for diagnosis, but they are more useful for monitoring response to treatment.

Other Comments:

Panel includes HCG, AFP, placental ALP in CSF

Referred to North West London Pathology Lab: https://www.nwlpathology.nhs.uk/tests-database/human-chorionic-gonadotrophin-hcg-rapid-tumour-marker/