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Radiol Case Rep
Radiol Case Rep
Radiology Case Reports
1930-0433
Elsevier

S1930-0433(24)00750-7
10.1016/j.radcr.2024.07.163
Case Report
Intraabdominal mature cystic teratoma in a 20-year-old male: A rare case
Santiana Leni MD a
Khairuddin Rais MD rais.khairuddin@gmail.com
a⁎
Hernowo Bethy S. MD, PhD b
a Department of Radiology, Faculty of Medicine, Universitas Padjadjaran, Dr. Hasan Sadikin General Hospital, Bandung, Indonesia
b Department of Anatomical Pathology, Faculty of Medicine, Universitas Padjadjaran, Dr. Hasan Sadikin General Hospital, Bandung, Indonesia
⁎ Corresponding author. rais.khairuddin@gmail.com
21 8 2024
11 2024
21 8 2024
19 11 51195123
26 6 2024
26 7 2024
28 7 2024
© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.
2024

https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Teratomas are the most prevalent type of germ cell tumors and usually display benign characteristics. Mature cystic teratomas consist of a varied mixture of mature tissue types that originate from squamous epithelium and skin adnexal structures. It is most commonly found in female gonads. A mature teratoma located in the abdomen of an adult male patient is exceptionally uncommon. In this case, we report a rare case of intra-abdominal mature cystic teratoma in an adult male.

Keywords

Computed tomography scan
Mature cystic teratoma
Mesentery
Intraabdominal
Young adult
Ultrasonography
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pmcIntroduction

Teratomas, categorized within the spectrum of germ cell tumors (GCTs), consist of a range of cellular or organoid components that resemble the typical derivatives found in multiple germ layers. These tumors can develop at any age, from infancy to adulthood [1]. They develop from versatile cells and consist of a broad range of tissues that are unrelated to the organ or location where they form [2]. Teratomas are the most prevalent type of germ cell tumors and usually display benign characteristics [3]. Teratomas are divided into 3 categories, namely mature (benign), immature (malignant), and monodermal or highly specialized [1]. Mature cystic teratomas comprise a diverse assortment of mature tissue types, originating from squamous epithelium and skin adnexal structures [3]. These tumors are typically located in gonads but can occasionally be found elsewhere. The most common extragonadal sites are the sacrococcygeal and presacral regions. Mesenteric teratomas, on the other hand, are extremely rare, with an incidence of about 1 in 27,000 to 100,000 admissions [4,5]. Mature cystic teratomas are predominantly found in females, constituting about 10%-20% of all ovarian tumors. In males, they are extremely rare, comprising less than 1% of teratomas [1]. A mature teratoma located in the abdomen of an adult male patient is exceptionally uncommon [6]. In this case, we present a rare case of a mature cystic teratoma within the abdomen of an adult male. We emphasize the significance of multimodal imaging in recognizing the distinctive features associated with mature teratomas.

Case presentation

A 20-year-old male presented with painless progressive abdominal enlargement felt for the past 3 years. The complaint was accompanied by a sensation of bloating and fullness. There were no defecation and urination problems.

Abdominal ultrasound examination revealed a large unilocular fluid-filled cystic mass measuring 23 × 17 × 20 cm in the right upper quadrant and mid-abdomen with internal echogenic debris and multiple floating spherical masses (Fig. 1A). Internal vascularity is absent on color Doppler examination, with posterior acoustic enhancement confirming the cystic nature of the mass (Figs. 1B and C). The origin of the mass is indeterminate, either from the liver or mesentery, with evidence of mass effect on the surrounding viscera such as the liver and right kidney.Fig. 1 (A) US image of the right upper to mid abdominal quadrant shows a large unilocular fluid-filled cystic mass with internal echogenic debris (solid arrow) and multiple floating spherical masses (dashed arrow), posterior acoustic enhancement indicating a cystic nature of the mass was also noted, (B and C) color Doppler showed absent internal vascularity.

Fig 1

Abdominal computed tomography (CT) scan revealed a circumscribed, large (22 × 19 × 21 cm), thinly encapsulated abdominal cystic mass with internal septation, calcification, and numerous internal nondependent 3–5-cm spheroid masses with fat density, exerting mass effect on the liver and the surrounding abdominal viscera, such as the right kidney, the stomach, and small intestines. The fluid within the cyst was simple, measuring 13 HU. The spheroid masses were nonenhancing and hypoattenuating (averaging between −14 HU and –10 HU) when compared with the surrounding fluid (Fig. 2).Fig. 2 (A) Axial, (B) coronal, and (C) sagittal contrast-enhanced abdominal CT shows a large thinly encapsulated abdominal cystic mass with internal septation (solid arrow), calcification (arrowhead), and numerous internal nondependent spheroid masses with fat density (dashed arrow) (not clearly identified as in ultrasound), with exerting mass effect on the liver (L) and surrounding abdominal viscera, such as the right kidney (RK), pancreas (P), bowel (B), and small intestines (SI).

Fig 2

Pathologic evaluation was performed on the patient's tumor tissue. On macroscopic examination, the cystic tissue appears brownish-white, rubbery, with a smooth outer surface and brownish patches on the inner surface, with wall thickness ranging 0.3–1 cm. Smaller tissues, with an average size of 1.5 cm in diameter, were composed of hair and teeth, with yellowish butter-like material. Microscopic examination (Fig. 3) showed that the cyst wall consisted of ectoderm components in the form of keratinized stratified squamous epithelium, hair follicles, sebaceous glands, and sudoriferous glands. Mesoderm components were found in the form of adipocytes and osteocytes. Endoderm components consisted of columnar pseudostratified epithelium, seromucous glands lined with columnar epithelium. The pathological examination supported intraabdominal mature cystic teratoma.Fig. 3 Histopathological examination shows mesoderm component in the form of adipocytes (A) and bone tissue with normal osteocytes (B), endoderm component, which consist of columnar pseudostratified epithelium and seromucous glands lined with columnar epithelium (C) ectoderm elements in the form of keratinized stratified squamous epithelium and skin adnexa (D) (H-E stain; original magnification; x100).

Fig 3

Discussion

Germ cell tumors (GCT) are exceptionally rare, with an incidence of about 12 cases per 1 million individuals under the age of twenty [5]. Teratoma, typically a germ cell tumor arising from the gonads, is usually found in females of reproductive age. Germ cells migrate from the yolk sac to the genital ridge via the hindgut during development, explaining the occurrence of teratomas in unusual locations [7]. Mature teratomas are considered congenital neoplasms that contain tissue from multiple germ cell layers—endoderm, mesoderm, and ectoderm. These tumors are characterized by their well-differentiated tissue types and lack of immature components [6].

In this patient, according to the abdominal ultrasound examination result, it was unclear whether the mass was from the liver or mesentery. Teratomas or the liver are rare, with only 25 cases of true liver teratomas reported in the radiology literature [8]. Mesenteric teratomas are also extremely rare, with fewer than 25 reported cases, primarily documented as single case reports. They predominantly occur in infants, children, and young adults [2].

Mature cystic teratomas in adult males typically manifest as large tumors, measuring 5 to 10 cm in diameter. These tumors exhibit a diverse composition of tissues, resulting in a heterogeneous appearance, comprising solid, cartilaginous, and cystic areas. Microscopically, they reveal collections of specialized cells or organoid structures embedded within a fibrous or myxoid stroma, including neural tissue, muscle bundles, cartilage islands, squamous epithelium, and fragments reminiscent of various organs like the thyroid gland, bronchial epithelium, and intestinal or brain tissue. These elements may exhibit either mature characteristics resembling adult tissues or immature features akin to fetal or embryonic tissue [1].

On imaging, mature cystic teratomas typically present as cystic masses enclosed in a clear capsule containing sebaceous fluid. While predominantly unilocular, they can also be multilocular. These teratomas commonly include fat components, calcifications, like teeth or bone, and frequently contain floating masses of hair or soft tissue [6,9]. In this patient, the tumor also contains hair, teeth, osteocytes, and cartilage. The most specific indicator of a mature teratoma is the presence of intratumoral fat, either as sebum or macroscopic fat. Typically, mature teratomas generate and contain epithelial and sebaceous elements. Fat and sebum should display consistent imaging characteristics across all modalities. These include hypoattenuation (usually less than −20 HU) on CT scans, high signal intensity on T1-weighted and fast spin-echo T2-weighted MR images, and low signal intensity on fat-saturated MR images [6]. In this patient, the spheroid masses revealed by abdominal CT scan showed a nonenhancing and nonhypoattenuating appearance compared with the surrounding fluid, which gives an overview of the appearance of fat and sebum.

The diagnosis should involve the utilization of conventional abdominal tumor diagnostic techniques, including ultrasonography (US) and computed tomography (CT) [2]. Ultrasound is essential in assessing the contents of mature cystic teratomas. While mature cystic teratomas may present with diverse appearances on ultrasound, they are typically identified by the presence of echogenic sebaceous material and calcification. Computed tomography (CT) provides enhanced sensitivity in assessing the impact of these cysts on adjacent organs, particularly the intestine [2,10]. Computed tomography (CT) is highly effective in imaging anatomical features of teratomas. A plain CT scan can reveal a soft tissue or fat-density mass, sometimes showing rim calcification or tooth-like components [5,11]. An accurate diagnosis of mesenteric tumors can only be achieved through open laparotomy, as preoperative diagnosis, even with CT, is only 25% accurate. Surgery is essential not only to confirm the diagnosis definitively but also to prevent potential complications [2,12]. Total cystectomy is the preferred treatment, with reports of successful laparoscopic procedures. Nonsurgical management is advised for asymptomatic lesions under 6 cm due to slow growth rates [2,13]. Radiation therapy could also serve as a treatment alternative for tumors containing significant quantities of germinoma, as it is generally responsive to radiation [6,14].

Rarely, mature teratomas can lead to complications such as rupture, infection, malignant transformation, hormone excretion (such as struma ovarii), and torsion in ovarian teratomas. Large tumors can cause mass effects on nearby structures. Rupture may result in sebaceous content leakage into the peritoneum, causing granulomatous peritonitis. Malignant transformation occurs in 2%-3% of cases, predominantly in children, with squamous cell carcinoma being the most common. Other potential cancers include adenocarcinomas, sarcomas, and carcinoids. Concerning signs for malignancy include irregular wall thickening, irregular margins, and invasion of adjacent structures [6,10,15,16].

Conclusion

Intraabdominal mature cystic teratoma in an adult male is extremely rare. Even though histopathological examination is needed for confirmation of the diagnosis, imaging modalities such as ultrasound and CT scan, which was done in our case, may help in identifying characteristics and components suggestive for mature teratomas, especially if not found in the common location.

Patient consent

I confirm that written informed consent for the publication of this case report has been obtained from the patient.

Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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