Collision Glial Neoplasms Arising in an Ovarian Mature Cystic Teratoma: A Rare Event

Low-Grade Glioma within Mature Cystic Teratoma in a Patient with Anti-N-Methyl-D-Aspartate Receptor Encephalitis: A Case Report

Introduction

Mature cystic teratoma (MCT) is a common type of ovarian tumors that can, in rare cases, undergo malignant transformation. It has been discovered that MCT patients may experience psychiatric symptoms due to the presence of anti-N-methyl-D-aspartate receptor (NMDAR) antibodies, which is the underlying cause of autoimmune encephalitis. Here, we present the first documented case of a patient with anti-NMDAR encephalitis who also had a morphology of low-grade glioma within MCT.

Case Report

A 45-year-old woman presented with seizures, altered consciousness, abnormal NMDAR antibody IgG titers, and abnormal brain MRI findings confirm the diagnosis of anti-NMDAR encephalitis. Physical examination revealed an oval mixed echo mass measuring 54 × 37 mm in the left adnexal area on ultrasound of the uterine appendage. The patient underwent laparoscopic left ovarian and fallopian tube resection. The pathological gross examination revealed a pile of grayish-red cystic and solid fragmented tissue measuring 7 × 6 × 2.2 cm. Histological examination revealed characteristic components of MCT. Furthermore, the solid component of the gross tissue showed proliferative and densely arranged astrocytes with cellular atypia, which were positive for GFAP and Olig-2, negative for IDH1 and EMA. And the Ki67 index was approximately 10%, suggesting the presence of low-grade glioma lesions. The patient was diagnosed with malignant transformation of MCT into a morphology of low-grade glioma, not otherwise specified. After the removal of the ovarian tumor, the patient's psychiatric symptoms improved.

Conclusions

Low-grade glioma within MCT is a rare occurrence, and the presence of this malignant transformation in patients with anti-NMDAR encephalitis is even more uncommon.

Mature ovarian teratoma with gliomatosis peritonei: A rare case report

Gliomatosis peritonei (GP) is rarely observed along with mature ovarian teratoma. However, it is important to recognize the benign nature of GP when associated with mature ovarian teratoma. Treatment for primary tumor and long-term follow-up is vital.

Dentigerous Equine Teratoma in a Stallion: Surgical Management and Clinicopathology

Teratoma is a rare germ cell testicular cancer composed of cells that are not normally present in the site where it originates. These tumors are rarely described in horses, where they may develop due to cryptorchidism. Teratomas consist of cells originating from different germinal layers, arising from germinal multi-potential cells with differentiation defects, and can simultaneously contain several tissues from two or more embryonic layers. Testicular teratomas are described in horses, cats, dogs, wild boars, bulls, and humans. In the rare descriptions found in literature of testicular teratoma in stallions, they occur frequently in cryptorchid testicles, as a consequence of congenital neoplasm. To our knowledge there is no other report of a dentigerous equine teratoma in a stallion. We describe here a successful laparoscopic removal of a testicular teratoma and its clinic-pathological features.