J Pathol Transl Med.  2017 Jan;51(1):49-55. 10.4132/jptm.2016.09.19.

Diagnostic Significance of Cellular Neuroglial Tissue in Ovarian Immature Teratoma

• Chai Y
• Woo CG
• Kim JY
• Kim CJ
• Khang SK
• Kim J
• Park IA
• Kim EN
• Kim KR

• KMID: 2367680
• DOI: http://doi.org/10.4132/jptm.2016.09.19

Abstract

BACKGROUND
Immature teratoma (IT) is a tumor containing immature neuroectodermal tissue, primarily in the form of neuroepithelial tubules. However, the diagnosis of tumors containing only cellular neuroglial tissue (CNT) without distinct neuroepithelial tubules is often difficult, since the histological characteristics of immature neuroectodermal tissues remain unclear. Here, we examined the significance of CNT and tried to define immature neuroectodermal tissues by comparing the histological features of neuroglial tissues between mature teratoma (MT) and IT.
METHODS
The histological features of neuroglial tissue, including the cellularity, border between the neuroglial and adjacent tissues, cellular composition, mitotic index, Ki-67 proliferation rate, presence or absence of tissue necrosis, vascularity, and endothelial hyperplasia, were compared between 91 MT and 35 IT cases.
RESULTS
CNTs with a cellularity grade of ≥ 2 were observed in 96% of IT cases and 4% of MT cases (p < .001); however, CNT with a cellularity grade of 3 in MT cases was confined to the histologically distinct granular layer of mature cerebellar tissue. Moreover, CNT in IT exhibited significantly higher rates of Ki-67 proliferation, mitoses, and necrosis than those in MT (p < .001). Furthermore, an infiltrative border of neuroglial tissue and glomeruloid endothelial hyperplasia were significantly more frequent in IT cases than in MT cases (p < .001).
CONCLUSIONS
Our results suggest that if CNT with a cellularity grade of ≥ 2 is not a component of cerebellar tissue, such cases should be diagnosed as IT containing immature neuroectodermal tissue, particularly if they exhibit an infiltrative border, mitoses, necrosis, and increased Ki-67 proliferation.

Keyword

Immature teratoma; Neuroectodermal; Neuroglia; Neuroepithelium; Ki-67; Ovary

MeSH Terms

Diagnosis
Female
Hyperplasia
Mitosis
Mitotic Index
Necrosis
Neural Plate
Neuroglia
Ovary
Teratoma*

Figure

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  Fig. 1. Cellular neuroglial tissue. The diagnosis of immature teratoma containing only cellular neuroglial tissue without distinct neuroepithelial tubules is often difficult since the histological characteristics of immature neuroectodermal tissues have not been clearly defined.

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  Fig. 2. Cellularity of neuroglial tissue in mature and immature teratomas. (A) Grade 1 referred to cellularity comparable to that of normal white matter or an inter-nuclear distance longer than 5 nuclear diameters. (B, C) Grade 2 applied to cases with either heterogeneous cellularity or with inter-nuclear distances similar to 2–4 nuclear diameters. (D) Grade 3 cellularity referred to cellularity comparable to that of the germinal matrix of the fetal brain or the granular layer of the normal adult cerebellum wherein nuclei touch each other, or an inter-nuclear distance shorter than 1 nuclear diameter.

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  Fig. 3. Histopathologic Features Of Mature Teratoma And Immature Teratoma. Neuroglial Cells In A Mature Teratoma Show A Smooth Border (A), And Comprise Polymorphous Cellular Components (C). They Show No Mitotic Activity (E) And No Coagulative Necrosis (G), But Do Exhibit Focally Glomeruloid Endothelial Proliferation (I) And Rare Ki-67– Positive Proliferating Cells (K). In Contrast, Cellular Neuroglial Cells In Immature Teratoma Show An Infiltrative Border (B) More Frequently, And Comprise Monomorphic Germinal Matrix-like Cells (D). They Also Show Frequent Mitoses (F), Coagulative Necrosis (H), Glomeruloid Endothelial Proliferation (J), And Increased Ki-67–positive Proliferating Cells (L).

Reference

1. Koulos JP, Hoffman JS, Steinhoff MM. Immature teratoma of the ovary. Gynecol Oncol. 1989; 34:46–9.

2. Gershenson DM, del Junco G, Silva EG, Copeland LJ, Wharton JT, Rutledge FN. Immature teratoma of the ovary. Obstet Gynecol. 1986; 68:624–9.

3. Boor PJ, Schoene WC. Fetal cerebellar tissue associated with a primitive neuro-epithelial tumor in an ovarian teratoma. Can J Neurol Sci. 1975; 2:139–41.

4. Kleinman GM, Young RH, Scully RE. Primary neuroectodermal tumors of the ovary: a report of 25 cases. Am J Surg Pathol. 1993; 17:764–78.

5. Talerman A, Vang R. Germ cell tumors of the ovary. In: Kurman RJ, Ellenson LH, Ronnett BM, eds. Blaustein’s pathology of female genital tract. 6th ed. New York: Springer;2011. p. 847–907.

6. Smith HO, Berwick M, Verschraegen CF, et al. Incidence and survival rates for female malignant germ cell tumors. Obstet Gynecol. 2006; 107:1075–85.

7. Gallion H, van Nagell JR Jr, Donaldson ES, Hanson MB, Powell DF. Immature teratoma of the ovary. Am J Obstet Gynecol. 1983; 146:361–5.

8. Sanes DH, Reh TA, Harris WA. Development of the nervous system. San Diego: Academic Press;2006. p. 57–85. 2nd.

9. Kierszenbaum AL. Histology and cell biology: an introduction to pathology. St. Louis: Mosby;2002. p. 199–225.

10. Ballabh P, Braun A, Nedergaard M. Anatomic analysis of blood vessels in germinal matrix, cerebral cortex, and white matter in developing infants. Pediatr Res. 2004; 56:117–24.

11. Dummula K, Vinukonda G, Xu H, et al. Development of integrins in the vasculature of germinal matrix, cerebral cortex, and white matter of fetuses and premature infants. J Neurosci Res. 2010; 88:1193–204.

12. Sugiyama T, Osumi N, Katsuyama Y. The germinal matrices in the developing dentate gyrus are composed of neuronal progenitors at distinct differentiation stages. Dev Dyn. 2013; 242:1442–53.

13. Baker PM, Rosai J, Young RH. Ovarian teratomas with florid benign vascular proliferation: a distinctive finding associated with the neural component of teratomas that may be confused with a vascular neoplasm. Int J Gynecol Pathol. 2002; 21:16–21.

14. Gaudin PB, Rosai J. Florid vascular proliferation associated with neural and neuroendocrine neoplasms: a diagnostic clue and potential pitfall. Am J Surg Pathol. 1995; 19:642–52.