|Year : 2019 | Volume
| Issue : 3 | Page : 216-218
Mature cystic teratoma of renal pelvis: An unusual presentation at an uncommon site
Bhuvanagiri Srihari Balaji, Immanuel Sampath Karl
Department of Paediatric Surgery, CMC, Vellore, Tamil Nadu, India
|Date of Web Publication||6-Jun-2019|
Dr. Bhuvanagiri Srihari Balaji
Department of Paediatric Surgery, CMC, Vellore - 632 004, Tamil Nadu
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Teratoma of the kidney is uncommon. We report a case of a young boy with a large, right-sided retroperitoneal cyst suspected as lymphangioma causing hydronephrosis. His renal pelvis was dilated, containing purulent fluid, and a nephrectomy was performed. Histopathology revealed a mature cystic teratoma of the renal pelvis.
Keywords: Cystic, kidney, mature, teratoma
|How to cite this article:|
Balaji BS, Karl IS. Mature cystic teratoma of renal pelvis: An unusual presentation at an uncommon site. J Indian Assoc Pediatr Surg 2019;24:216-8
|How to cite this URL:|
Balaji BS, Karl IS. Mature cystic teratoma of renal pelvis: An unusual presentation at an uncommon site. J Indian Assoc Pediatr Surg [serial online] 2019 [cited 2020 Jul 12];24:216-8. Available from: http://www.jiaps.com/text.asp?2019/24/3/216/259748
| Introduction|| |
Teratomas are relatively uncommon tumors, occurring mostly in the ovaries, sacrococcygeal region, testes, central nervous system, and mediastinum and only rarely in other locations. Retroperitoneal teratomas comprise 3.5%–4% of all germ cell tumors in children. Primary renal teratoma is rare; only about 30 cases have been described.
| Case Report|| |
A 10-year-old male child presented with gradually progressive abdominal distension since infancy. On examination, he had a nontender, large, firm cystic mass extending from the costal margin up to the pelvis, predominantly occupying the right half of the abdomen, but also partly crossing the midline to the left. Both his testes were descended and normal. On evaluation, computed tomography (CT) scan revealed a retroperitoneal cystic mass measuring 28 cm × 18 cm × 12.3 cm extending from the right bare area of the liver and right posterior pararenal space up to the iliac vessels and the urinary bladder. It was displacing the right kidney and causing mild hydronephrosis. Multiple internal septations were noted within the superior part of the lesion. There were no calcifications or fat density [Figure 1], [Figure 2], [Figure 3].
|Figure 1: Mass extending from the bare area of the liver up to the urinary bladder|
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|Figure 2: Large retroperitoneal lesion crossing the midline anterior to the aorta|
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|Figure 3: Computed tomography image of the retroperitoneal cystic lesion and the normal functioning left kidney|
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The liver had no focal lesions. There was no vascularity on color Doppler. These features and the age of presentation indicated a retroperitoneal lymphangioma. The absence of fat density and calcifications were against a teratoma. Diethylenetriamine pentaacetic acid (DTPA) renogram revealed right hydronephrosis with severe parenchymal dysfunction (9% function). Tumor markers such as alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (HCG) were assessed as previous ultrasound scans done elsewhere had mentioned teratoma as one of the differentials in addition to lymphatic cyst or hydatid cyst. The tumor marker levels were found to be normal. Hematological and renal parameters were normal [Figure 4].
|Figure 4: Diethylenetriamine pentaacetic acid renogram showing poor function of the right kidney|
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Intraoperatively, the renal pelvis was found to be massively dilated containing 2 L of purulent fluid, and it was nonadherent to any adjoining structure. No separate mass lesion was identified. The ureter was normal. These on table findings indicated a probable pelvic-ureteric junction obstruction with secondary infection of the stagnated urine. In view of this and the poor renal function, a right nephrectomy was performed.
Gross examination revealed a cystic neoplasm adherent to the kidney measuring 22 cm in diameter and filled with cheesy yellow material and hemorrhage. Microscopy revealed a cystic neoplasm composed of fibrocollagenous wall lined by stratified squamous epithelium and containing mature adipose tissue, skeletal muscles, nerve bundles, pilosebaceous units, and hair shafts. There were no immature elements or evidence of malignancy. The stroma of the neoplasm was in continuity with the renal pelvic stroma. It was reported as mature cystic teratoma arising from the hilar region of the right kidney.
| Discussion|| |
Teratoma is one of the five major histologic subtypes of germ cell tumors. The others are yolk sac tumor, germinoma, embryonal carcinoma, and choriocarcinoma. By definition, teratomas contain tissue elements from all the three germ layers. Teratomas are histologically graded and classified as immature or mature depending on the presence or absence of primitive neuroepithelial elements. AFP and beta-HCG are tumor markers secreted by malignant germ cell neoplasms such as yolk sac tumor and choriocarcinoma respectively. Mature teratoma does not cause elevation of tumor markers, whereas immature teratoma could be associated with elevated AFP, especially if it contains microscopic foci of yolk sac tumor.
Retroperitoneal teratomas comprise 3.5%–4% of all germ cell tumors in children. They generally tend to be large and well circumscribed, with a variegated gross appearance on section reflecting the presence of diverse tissue elements. Immature teratomas tend to be more solid than mature ones. When a retroperitoneal teratoma occurs during infancy, it can be mistaken with Wilm's tumor, neuroblastoma or other intra-abdominal malignancies of infancy. Complete surgical excision is the treatment of choice, but it may not always be possible due to large tumor size or proximity to vital structures. Primary renal teratoma is a rare entity. Its presenting symptoms include abdominal mass, abdominal pain, anorexia, vomiting, constipation, and hematuria. Sometimes, they are incidentally detected.
Grossly, teratomas contain both solid and cystic areas. When a teratoma arising from the kidney is predominantly cystic, it can be mistaken with cystic lesions of the kidney or hydronephrosis. The differential diagnosis of cystic abdominal masses in children is not always possible preoperatively, and it is difficult to characterize them intraoperatively, especially when they are very large. Sometimes, their site of origin can be difficult to ascertain, when they distort the local anatomy.
Abdominal ultrasound is the imaging of choice for initial evaluation. Ultrasound would reveal a cystic or mixed solid-cystic or hyperechoic mass with occasional coarse foci of calcification. On plain X-ray, intrarenal teratomas can appear as large, unilateral abdominal masses with calcifications and at times crossing the midline. The presence of teeth or formed bony components such as phalanges on plain X-ray is pathognomonic of a teratoma. In the presence of these features, ultrasound alone might be sufficient to plan surgical excision. In the absence of these features, CT scan or magnetic resonance imaging is used for confirmation and further characterization.
On CT, mature teratoma of the retroperitoneum manifests as a complex mass containing a well-circumscribed fluid component, adipose tissue, and calcification. The presence of hypoattenuating fat within the cyst and calcifications in the cyst wall is highly suggestive of cystic teratoma. In our patient, the CT scan revealed a large retroperitoneal cystic lesion with internal septations but no fat or calcifications in the wall. These findings were more in favor of a cystic lymphangioma. An elongated shape and a crossing from one retroperitoneal compartment to an adjacent one were also characteristics of cystic lymphangioma.
Although we could not identify the pathology preoperatively, it did not affect management as the treatment of choice for cystic intrabdominal masses in children is complete surgical excision. Upfront excision without preoperative histological diagnosis is warranted if the lesion can be completely excised without significant morbidity as per imaging characteristics. Preoperative histological diagnosis is necessary if the lesion involves adjacent structures, thereby raising the suspicion of malignancy. The CT scan findings in our patient were in favor of a benign lesion, and it could be excised completely. Normal tumor marker levels were against a malignant germ cell neoplasm. The pathology was identified postoperatively to be a mature cystic teratoma, and surgical excision with negative margins is curative for this condition.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]