immature teratoma

immature teratoma

Adults
A teratoma with both mature elements from all 3 germ-cell layers (ectodermal, mesodermal, and endodermal), and immature (embryonic, not foetal) tissues, most commonly of neural origin, consisting of primitive neurotubules, neuroepithelial rosettes, immature glial elements, immature ependyma, primitive muscle.

Prognosis
Relatively good if under age 15; guarded if adult (see table).

Grade, Immature teratoma
I)  ≤ 1 focus/slide contains immature tissue—low-grade.
II)  2–3 foci contains immature tissue—high-grade, adjuvant radiation therapy; survival possible.
III) 4+ foci contains immature tissue—high-grade, adjuvant radiation therapy; prognosis very poor.

Based on any immature tissue on any 1 slide at 40X (low-power field).

Children
Immature teratomas behave differently in children; grading is unnecessary, the only histological predictor of recurrence is the presence of foci of yolk-sac tumour (confirmed by IHC stains for CK, AFP, glypican 3, SALL4); immature neural tissue does not indicate malignancy in immature teratomas of infants as it does in adults.

immature teratoma

Malignant teratoma A teratoma that has mature elements from all 3 germ cell layers–ectodermal, mesodermal, and endodermal, and immature tissues, most commonly of neural origin; the neural tissues in ITs consist of primitive neurotubules, neuroepithelial rosettes, immature glial elements, immature ependyma
References in periodicals archive ?
A 36-year-old woman presented 6 years after oophorectomy for a right adnexal mass reported on histopathology as an immature teratoma.
Peritoneal gliomatosis has also been associated with GTS, with some suggestion that initial association of immature teratoma with peritoneal gliomatosis may predict future development of GTS.
reported 126 patients with SCT and the histology showed mature teratoma in 69%, immature teratoma in 20%, and endodermal sinus tumor in 11% of patients (8).
Mature or immature teratoma with additional malignant component
One important difference is that, unlike the situation in the adult testis or in congenital/pediatric GCT, the distinction between mature and immature teratoma is important in the adult mediastinum.
In the neonate, the diagnosis of an immature teratoma is is routinely based on the presence of immature neuroepithelium.
Histology identified an immature teratoma that was made up of tissue derived from various germ-cell layers and comprised mature glial/neurofibrillary tissue with scattered neurons predominant (figure 2).
Four histologic variants of teratoma are described: (1) mature teratoma, (2) immature teratoma, (3) teratoma with malignant transformation, and (4) monodermal teratoma.
The differential diagnosis of EWT includes metastatic Wilms tumor, embryonal rhabdomyosarcoma, immature teratoma, and malignant mixed mullerian tumor (MMMT).
One reported case of an immature teratoma admixed with a grade 1 endometrial adenocarcinoma was characterized by an admixture of squamous and mucinous epithelium, cartilage, bone, dental tissue, and a conspicuous immature neuro-epithelial component.
Immature teratomas are rare, but are considered malignant, and chemotherapy is warranted in such cases.
Immature teratomas are very rare and constitute only 1% of all teratomas.