Abstract

Teratomas are neoplasms that originate from germ cells and form somatic tissues during various stages of maturation and differentiation. Retroperitoneal teratoma is a rare disease in the adult population, with an incidence of 0.003%. In general, this condition tends to be asymptomatic and is frequently detected incidentally through imaging or during clinical examinations. We report a case of laparoscopic excision of a mature retroperitoneal teratoma in a young male at a military hospital. A 19-year-old soldier presented at the emergency department with recurrent abdominal pain and constipation. After consulting the general surgery team, a mature teratoma was suspected based on the predominance of hypoattenuating fat and the presence of mixed solid and cystic components. The mature teratoma was laparoscopically excised, and the patient was discharged in a satisfactory medical condition on postoperative day 26, without any complications. Surgical excision is strongly recommended when teratomas are detected in adults.

Keywords: Retroperitoneal Teratoma; Male Teratoma; Laparoscopic Excision; Military Hospital

Introduction

Teratomas are neoplasms that arise from the germ cells of all three primitive embryonic layers (ectoderm, mesoderm, and endoderm) and forms somatic-type tissues at various stages of maturation and differentiation [1]. There are numerous theories about teratomas; nowadays, the Germ Cell Theory is the most widely accepted. According to the Germ Cell Theory, these cells undergo differentiation to give rise to the tissue components of the mesoderm, ectoderm, and endoderm. The migratory potential of germ cells might be responsible for the anatomical variations observed in these tumors and their predilection for development in the gonads and midline structures [2]. Teratomas typically manifest as nodular and firm masses with variable combinations of cystic and solid components. The cysts may be occupied by keratinous material, clear serous, or mucoid fluid. Additionally, solid regions might contain gray-white nodules, indicative of cartilage, and consist of various types of tissues, including adipose tissue, hair, muscle, and bone [3]. Common locations for Extragonadal teratomas commonly occur in central structures along the midline, such as the intracranial pineal gland, anterior mediastinum, retroperitoneum, and sacrococcygeal regions [4]. Primary retroperitoneal teratomas constitute 1-11% of retroperitoneal neoplasms and predominantly manifest in neonates. As per the literature, there is a bimodal distribution, with a first peak observed during the initial 6 months of life, followed by another peak in early adulthood. Approximately half of the retroperitoneal teratomas are identified within the first year of life, with less than 20% detected in patients over 20 years of age [5,6]. In the adult population, retroperitoneal teratoma is a rare case; case reports in the literature describe their unique presentation. The estimated adult incidence is 1 in 40,000-63,000, and 1.4-6.3 patients per year have been described in major hospitals [7]. Here, we report a case of laparoscopic excision of a mature retroperitoneal teratoma in a young male at a military hospital.

Case Presentation

A 19-year-old soldier presented to the emergency department with recurrent abdominal pain and constipation. The patient had no relevant past medical history and family history. Physical examination results were unremarkable, with no abdominal tenderness or fullness. A digital rectal examination revealed no palpable mass. In addition, laboratory test results were within normal ranges. Abdominopelvic computed tomography (APCT) was performed immediately to determine the cause of abdominal pain. APCT revealed a noninvasive retroperitoneal mass located within the perirectal area. It measured approximately 6.3 × 8.3 cm, and the rectum deviated to the left side owing to the presence of a large mass (Figure 1A and 1B). After consulting the general surgery team, a mature teratoma was suspected based on the predominance of hypoattenuating fat and the presence of mixed solid and cystic components. Laparoscopic mass excision was planned, and the mass was observed on the right side of the sigmoid colon (Figure 2A). The anterior peritoneal reflection was dissected to encounter a large mass, which was circumferentially dissected from the surrounding tissue and completely removed (Figure 2B). After the removal of the mass, we confirmed preservation of the vas deferens and ureters (Figure 2C). Peritoneum was closed with barbed suture material using the laparoscopic technique (Figure 2D), and a closed suction drain was inserted into the excision area. No other intra-abdominal organ abnormalities were observed. Grossly, the specimen displayed an outer surface that appeared coarse and irregular surface (Figure 3A). The intracystic components were sebaceous and mucinous fluids along with multiple hair shafts (Figure 3B). Under microscopic examination, the lesion was identified as a cystic structure lined with keratinized stratified squamous epithelium and skin appendages, including hair shafts (Fig. 4A and 4C). Cortical bone, bone marrow tissue, and cartilaginous tissue (Figure 4B and 4D) also showed no indications of malignancy or immature components. All laboratory findings normalized on postoperative day (POD) 5, and the APCT showed no complications on POD 7. The patient was discharged in good medical condition on POD 26, without any complications.

Figure 1: APCT finding of retroperitoneal mature teratoma. A. Axial view of the retroperitoneal teratoma located within the peri-rectum area without invasion, approximately 6.3x8.3cm mass. B. Coronal view shows left-sided deviation of the rectum due to teratoma.