Mature teratoma of the pancreas diagnosed by fine-needle aspiration

Mature teratoma of the pancreas diagnosed by fine-needle aspiration

Arab Journal of Gastroenterology 12 (2011) 92–93 Contents lists available at ScienceDirect Arab Journal of Gastroenterology journal homepage: www.el...

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Arab Journal of Gastroenterology 12 (2011) 92–93

Contents lists available at ScienceDirect

Arab Journal of Gastroenterology journal homepage: www.elsevier.com/locate/ajg

Images in Gastroenterology

Mature teratoma of the pancreas diagnosed by fine-needle aspiration Amine Daghfous, Oussema Baraket ⇑, Sofiene Ayadi, Heykel Bedioui, Azzouz Heifa, Mohamed Jouini, Amine Makni, Wael Rebai, Faouzi Chebbi, Rachid Ksantini, Fadhel Fteriche, Montasser J. Kacem, Zoubeir Ben Safta Department of Visceral Surgery A, Hospital La Rabta, Tunis, Tunisia

Introduction Pancreatic teratomas are rare benign tumours. They are divided into two groups: mature and immature. The diagnosis is mainly based on imaging as computed tomography (CT) and magnetic resonance imaging (MRI) [1].

Case report A 41-year-old female patient, presented with recurrent epigastric pain of 2 years duration. Physical examination revealed a 15-cm epigastric mass that was mobile and tender on palpation. Abdominal ultrasound revealed a 20-cm hypoechoic mass, containing multiple hyperechoic structures. The exact origin of the mass could not be clearly defined. CT scan of the abdomen revealed a well-circumscribed voluminous cystic mass measuring approximately 25 cm in size, with heterogeneous content. After the administration of contrast material, no enhancement of the mass

was detected (Fig. 1). This mass was located in the pancreatic area, compressing the body of the stomach, spleen and the left kidney (Fig. 2). Abdominal MRI revealed a voluminous oval mass measuring 23  16  18 cm. It had high signal intensity on T2-weighted images, low signal intensity on T1-weighted images and showed no enhancement after the administration of gadolinium. The mass contained no septae but, the content was rather heterogeneous with a sediment, which was hypointense on T1-weighted images and hyperintense on T2-weighted images (Fig. 3). This formation seemed to be in the corporeal–caudal portion of the pancreas. It compressed the splenic artery and did not seem to communicate with the pancreatic main duct of Wirsung. CT-guided fine-needle aspiration of the pancreatic mass yielded sebum. Hence, the diagnosis of pancreatic teratoma was suggested. A distal pancreatectomy with splenectomy was performed. A 25-cm mass with fine walls developing into the omental bursa, pushing the stomach forward, and adhering to the transverse Mesocolon was detected. The mass arose from the distal part of the pancreas, encroaching on the splenic vessels, thereby pushing the splenic artery upwards and the splenic vein downwards. The cyst was excised and sent for histopathological examination. The

Fig. 1. A well-circumscribed mass with no enhancement after contrast injection on CT.

⇑ Corresponding author. Tel.: +216 21687404. E-mail address: [email protected] (O. Baraket).

Fig. 2. Mass is shown compressing the gastric body, the splenic region and the left kidney.

1687-1979/$ - see front matter Crown Copyright Ó 2011 Arab Journal of Gastroenterology. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.ajg.2011.04.009

A. Daghfous et al. / Arab Journal of Gastroenterology 12 (2011) 92–93

Fig. 3. Mass showing hyperintense-signal at T2 with a discretely heterogeneous content.

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The morphological aspect of pancreatic teratoma is variable depending on the mass’ components. On an abdominal ultrasound, a heterogeneous, hyperechoic, well-circumscribed mass without septae may be seen with hyperechoic fatty components composed of calcifications [2]. To further examine the cystic mass, an abdominal CT scan may be carried out, which allows better visualisation of the cystic content whether it was serous, sebaceous or mixed. The presence of a liquid content along with several calcifications is very suggestive of a pancreatic teratoma [1,2,4]. MRI showed a fatty content and allowed a better characterisation of the cystic content, which is rarely purely liquid. A hyperdense finding on T1- and T2-weighted images is another suggestive factor of a pancreatic teratoma. It is similar to that of the subcutaneous tissues [7]. The first preoperative diagnosis of cystic teratoma was carried out by Markovsky et al. in 1991 through cytological analysis of a specimen obtained from fine-needle aspiration [8]. However, the cytological aspects are not specific, except in the presence of mature squamous cells and keratin debris. In our observation, the radiological imagings of this cystic pancreatic mass were not specific. The differential diagnosis was either a pancreatic pseudocyst and pancreatic cystadenoma. The aspirated material was sent for cytological analysis. Due to presence of sebum in the specimen, the diagnosis of pancreatic teratoma was established and surgical resection was indicated. For Seki et al., ultrasound, CT and MRI were sufficient to diagnose teratoma of the pancreas [9]. Although pancreatic teratoma is a possible pre-cancerous lesion, only one case of malignant transformation has been reported in the literature [2,6]. Surgical resection is the only treatment for pancreatic teratomas [1,3]. In conclusion, mature teratoma of the pancreas is a rare benign tumour. Its preoperative diagnosis relies on modern imaging. In the atypical forms, fine-needle aspiration may be helpful to lead to the diagnosis and to adapt a therapeutic strategy. Total excision of the cyst is necessary, sometimes requiring a pancreatic resection to avoid recurrence. Conflicts of interest

Fig. 4. Histopathology of the mass with keratinous material and squamous cells.

The authors declared that there was no conflict of interest. histological examination of the specimen revealed a mature cyst containing sebaceous material and hair (Fig. 4). The patient developed a pancreatic fistula as a postoperative complication, which was successfully managed medically by somatostatin analogues and prolonged drainage. Discussion Cystic teratoma of the pancreas was first described by Ker in 1918 [2]. It is an extremely rare tumour. To our knowledge, 24 cases have been reported in the literature [3–6]. These tumours were derived from the totipotent stem cells, which possess the capacity to regenerate tissues from any of the three embryonic layers: the endoderm, the mesoderm and the ectoderm [2,3]. Pancreatic teratomas are classified into mature or immature, and according to consistency into either cystic or solid. They are most frequently located in the ovaries, the testis, the anterior mediastinum and the sacrococcygeal area. The pancreas remains the most uncommon area to find a teratoma [2,3].

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