Prenatal Diagnosis of Teratoma in a Torqued Undescended Testis Masked as Unclear Intra-Abdominal Mass

Introduction

Constantly improving ultrasound technologies facilitate prenatal detection of various fetal diseases, including low-incidence disorders that are typically diagnosed postnatally, such as testicular teratoma. These can appear as an unclear cystic intra-abdominal structure, caused by an undescended torqued testis. In the case of such uncertain cystic intra-abdominal lesions, a cryptorchidism could lead the investigator to narrow the possibilities to the urogenital tract.

Herein, we report the second case of a prenatally detected cystic-solid lesion being a testicular teratoma by a torqued undescended testis and the seventh case of a prenatally seen testicular teratoma. In late gestation, a structured evaluation of the testes would be beneficial to detect such malformations.

Case Report

A 24-year-old woman, gravida 3 para 0, was referred to our department at 30+3 weeks with an undefined cystic intra-abdominal mass in a male fetus. Ultrasound examination confirmed the predominantly cystic tumor with a small solid central part (8 × 13 mm), measuring a total size of 30.4 × 22.9 × 30.2 mm, without vascular flow. The tumor was located between the right lower renal pole and the bladder ([Fig. 1]). In its largest sagittal extension, the tumor reached into the right middle abdomen and was in cranial contact with the lower liver edge. Based on clinical features, a peritoneal cyst or mesenteric cyst was suspected. Further sonographic examinations at 34+4 and 40+0 weeks showed no signs of progress. At 40+2 weeks, a 3660-g male fetus with Apgar scores of 9, 10, and 10 at 1, 5 and 10 min, respectively, was delivered vaginally.

Fig. 1 Prenatal ultrasound images demonstrating teratoma in a torqued undescended testis at 30+3 (1 a) and 34+5 weeks of gestation (1 b and 1 c, respectively). The filled arrow indicates the cystic part and the dotted arrow the solid part of the torqued testis. The continuous arrow points to the fetal urinary bladder (1a). The intraabdominal tumor measures a total size of 28.9 × 21.7 mm, and the solid part measures a total size of 13.2 × 8.5 mm (1 b and c).

Postnatal ultrasound examination confirmed the prenatal findings. Moreover the heterogeneous, well-defined round mass (19 × 26 × 23 mm) showed central calcifications, as well as intralesional septations with an absence of vascular flow. There was no evidence of affected lymph nodes, ascites, intestinal or urinary tract obstructions. An abdominal teratoma was assumed and laparotomy was performed on day 8 of life.

A 28 × 22 × 16 mm beige-colored hard tumor, which most closely resembled a torqued testis, was completely resected. Histological diagnosis was teratoma in a necrotic right testis with focal inclusion of mature cell bone and cartilage tissue without evidence of malignancy. Necrotic changes were attributed to prenatal torsion.

The infant recovered well and was dismissed on the third day after surgery with normal serum AFP (preoperative 7311 ng/ml vs. 1660 ng/ml on the third postoperative day) levels.