Mature and immature teratomas arise primarily in the sacrococcygeal region of neonates and young children and in the ovaries of pubescent girls. These tumors are also less commonly found in the testicular region of boys younger than 4 years, the mediastinum of adolescents, and other sites.[1,2,3]
Although they comprise fewer than 1% of all gastrointestinal (GI) tumors, gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the GI tract. It has been estimated that there are 3,300 to 6,000 new GIST cases per year in the United States. A study based on Surveillance, Epidemiology and End Results (SEER) registry data found that the age-adjusted yearly incidence of GIST in the United States was 6.8 per million from 1992 to 2000. However, the...
The sacrococcygeal region is the primary tumor site for the majority of benign and malignant germ cell tumors (GCTs) diagnosed in neonates, infants, and children younger than 4 years. These tumors occur more often in girls than in boys; ratios of 3:1 to 4:1 have been reported. Sacrococcygeal tumors present in two clinical patterns related to the child's age, tumor location, and likelihood of tumor malignancy. Neonatal tumors present at birth protruding from the sacral site are usually mature or immature teratomas. Among infants and young children, the tumor presents as a palpable mass in the sacropelvic region compressing the bladder or rectum. These pelvic tumors have a greater likelihood of being malignant. An early survey found that the rate of tumor malignancy was 48% for girls and 67% for boys older than 2 months at the time of sacrococcygeal tumor diagnosis, compared with a malignant tumor incidence of 7% for girls and 10% for boys younger than 2 months at the time of diagnosis. The pelvic site of the primary tumor has been reported to be an adverse prognostic factor, which may be due to either delayed diagnosis because it was unappreciated at birth or incomplete resection at the time of original surgery.[5,6,7,8]
After successful resection, neonates diagnosed with benign mature and immature teratomas are observed with close follow-up exams and serial serum alpha-fetoprotein (AFP) determinations for several years to ensure that the expected physiological normalization of AFP levels occurs and to facilitate early detection of tumor relapse. A significant rate of recurrence among these benign tumors has been reported by several groups, ranging from 10% to 21%, with most relapses occurring within 3 years of resection.[4,9,10,11] While there is no standard follow-up schedule, follow-up should include scans and tumor markers for 3 years. Importantly, 43% to 50% of these recurrent tumors will be malignant and require adjuvant chemotherapy. With early detection, these malignant GCTs can be treated successfully with surgery and chemotherapy (overall survival, 92%). Complete resection of the coccyx is vital to minimize the likelihood of tumor recurrence; however, one study reported that 11 out of 12 patients with microscopic residual benign immature teratoma had no recurrence. Long-term survivors should be monitored for complications of extensive surgery, which include constipation, fecal and urinary incontinence, and psychologically unacceptable cosmetic scars.