Epidemiology of Pineal Region Tumors in Children

Incidence and Prevalence

• Pineal region tumor incidence is 0.1–0.3 /100,000 / year (73): Tumors of the pineal region account for 0.4–1% of all intracranial tumors.  The incidence of pineal region tumors is higher in children, in whom 3–8% of intracranial tumors occur in the pineal region (36).  Epidemiological characteristics vary on the basis of tumor type. 
• Germinoma incidence is 0.1 / 100,000 / year (73): Pineal germ cell tumors are more common than pineal parenchymal tumors.  Germinoma is the most common pineal region tumor, accounting for up to 60% of intracranial germ cell tumors with a US incidence of 0.1 per 100,000 per year (8,25,37,41). In Japan its incidence is 5 fold higher (76).

Age Distribution

• Bimodal distribution of pineal tumors in teens and 30s: Pineal region tumors demonstrate a bimodal age distribution.  Most children with pineal region tumors present between 10 and 20 years of age (mean age of presentation, 13 years), while adults are typically diagnosed at age 30 years or older (73).
• Germinomas peak in adolescence: Most germinomas occur in the first three decades of life, with peak incidence in adolescence concordant with the onset of puberty (41, 61).
• Nongerminomatous germ cell tumors in the first two decades: Nongerminomatous germ cell tumors (NGGCTs), which include embryonal carcinomas, endodermal sinus tumors, and choriocarcinomas, affect males in the first two decades of life.  Choriocarcinomas affect younger patients, mean age 8 years, while embryonal carcinomas and endodermal sinus tumors occur at mean ages of 14 and 17 years, respectively (73).
• Teratomas in the first two decades: Teratomas are typically diagnosed within the first two decades of life and tend to occur in much younger children than do other germ cell tumors (73).
• Pineal parenchymal tumors show variable age distribution:  Pineoblastomas occur in infancy and childhood, although cases of neonatal and adult pineoblastomas have been reported (62).Pineocytomas occur more frequently in young adults (24).

Sex Predilection

• Germ cell tumors: Germ cell tumors of the pineal region demonstrate a male:female ratio of 4:1 (61). 
• Pineoblastomas: Pineoblastomas are slightly more common in males, with a male:female ratio of 2:1 (73).

Geographic Distribution

• More common in Asia: Germ cell tumors comprise a higher proportion of primary intracranial neoplasms in Japan, Taiwan and South Korea (2-11%) compared to incidence in Western countries (0.4-3.4%) (50,76). Pineal germinomas are 5 times more common in Japan than in Western countries (76).

Risk Factors

• None identified.

Relationships to Other Disease States and Syndromes

• Retinoblastoma and pineoblastoma: Pineoblastoma can occur in association with bilateral retinoblastoma, a condition known as trilateral retinoblastoma.  This condition is thought to be due to a mutation of a tumor suppressor gene on chromosome 13 (45).