- Email: [email protected]
Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation
G Model
JICC-334; No. of Pages 4 Journal of Indian College of Cardiology xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Journal of Indian College of Cardiology journal homepage: www.elsevier.com/locate/jicc
Case Report
Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation Gauranga Majumdar *, Navneet Kumar Srivastava, Surendra Kumar Agarwal, Shantanu Pande, Bipin Chandra Department of Cardiovascular and Thoracic Surgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow 226014, India
A R T I C L E I N F O
A B S T R A C T
Article history: Received 8 May 2016 Accepted 10 June 2016 Available online xxx
A teratoma is a tumour with tissue or organ components resembling normal derivatives of more than one germ layer.1 Anterior mediastinal teratoma with organoid structures is a rare presentation of germ cell tumour. We report a case of such a rare giant tumour (30 15 cm) in a young adult male of 18 years who presented with right-sided chest pain of 3 years duration. Surgical removal is the definitive treatment of a mature anterior mediastinal teratoma. The patient was operated successfully with complete removal of the tumour. As superior vena cava (SVC) was encased in the tumour wall causing SVC syndrome, partial resection of the pericardium was required to free SVC from the tumour. The defect in the Pericardium was repaired to prevent herniation of heart. In the Post-operative period, patient developed recurrent pneumothorax of the left side, which was successfully treated by intercostal tube drainage and pleurodesis. Post resection histopathology examination confirmed mature teratoma with representation from all the three germ layers including organoid differentiation of gastrointestinal tract. ß 2016
Keywords: Germ cell tumour (GCT) Mediastinal teratoma Organoid differentiation Intestinal loop
1. Introduction Most common extra gonadal site of germ cell tumour is the anterior mediastinum. Benign teratoma of mediastinum accounts for 3–12% of mediastinal tumours with approximately equal incidence in both genders.1 A mature teratoma is composed of several foci of mature tissue derived from at least two out of three embryonic germ layers (ectoderm, endoderm, mesoderm) and presence of all the three germ layers is rare.2 The tumour is composed of tissues which are foreign to the organ or anatomic site in which they arise. Usually tissue arising from different germ layer has no correlation in a mature teratoma. The case reported has a very large mature teratoma (30 15 cm) with fully developed gastrointestinal organoid differentiation manifesting as multiple intestinal loops (cystic component of the tumour), which was confirmed by histopathology. Organoid differentiation of anterior mediastinal teratoma has been reported only rarely in English literature, although ovary and sacrococygeal mature teratoma has been occasionally reported to contain different degree of organoid differentiation.3–5 This teratoma was occupying most of the right
* Corresponding author. E-mail address: [email protected] (G. Majumdar).
hemithorax, anterior and middle mediastinum, extending up to left hemi-thorax. Due to its massive size, pressure effect was clearly visible on right lung, which was compressed; into a small non-functional tissue mass; all the great vessels were compressed, particularly superior vena cava, which was embedded in the tumour raising its pressure to 30 mmHg. The heart and mediastinum were shifted to the left. Surgical removal of teratoma is the only definitive treatment, with no role of chemoradiation.1 Large lateral defect in the pericardium, which was required to isolate SVC from tumour mass in this case, was repaired to prevent potential herniation of the heart. Recurrent tension pneumothorax is an uncommon complication following large mediastinal teratoma removal. 2. Case report An 18-year-old boy presented with complaints of right-sided chest heaviness, pain and exertional dyspnoea for last one year. There was no history of cough, fever, weight loss or haemoptysis. Physical examination revealed a bulge in the right hemi thorax with dilated neck veins. Jugular venous pressure was markedly raised. Trachea was shifted to left on palpation. On auscultation, there was no air entry on right side, middle and basal zone; however, breath sounds were diminished in the apex. Breath
http://dx.doi.org/10.1016/j.jicc.2016.06.002 1561-8811/ß 2016
Please cite this article in press as: Majumdar G, et al. Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation, J Indian Coll Cardiol. (2016), http://dx.doi.org/10.1016/j.jicc.2016.06.002
G Model
JICC-334; No. of Pages 4 2
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sounds were normal in the left hemithorax. Other system examination, including external genitalia was normal. Chest X-ray revealed a well circumscribed homogenously opacified mass lesion occupying right hemithorax along with anterior mediastinum, extending up to left hemithorax with near total atelectasis of right lung. Trachea was deviated to left side with normal patency of left main bronchus with multiple area of calcification in the tumour mass (Fig. 1a). Computed tomography scan (CECT) chest revealed a large heterogeneous solid-cystic multiseptated and lobulated mass lesion (14.5 10.4 19.9 cm) containing areas of soft tissue and fatty attenuation, multiple coarse calcifications and calcified septal thickening in right hemithorax and anterior mediastinum (Fig. 2a–c). The giant mass caused significant contralateral mediastinal shift. Superior vena cava was encased by the mass in its upper portion causing partial SVC obstruction. Right pulmonary artery and their branches and pulmonary vein were compressed within the collapsed lung. Aorta was displaced leftward by the mass. Right lung appeared compressed and collapsed with some amount of aerated parenchyma noted in right apical region. Trachea and oesophagus were normal. Ultra sound examination of abdomen and external genitalia did not reveal any abnormality. All laboratory investigations along with tumour markers such as a-fetoprotein (AFP) and b-human chorionic gonadotropins (b-HCG) were normal. A CT guided fine needle aspiration cytology was suggestive of benign teratoma.
A primary median sternotomy was carried out, which provided excellent exposure of the tumour, and also allowed safe dissection of all mediastinal structures adherent to the tumour. The tumour was occupying most of the right thoracic cavity, anterior mediastinum and reaching up to medial one third of left thoracic cavity. A small incision was given on the tumour to allow the suction tip catheter to enter the cavity over a purse string suture. Copious pultaceous liquid material was sucked out from the tumour. The tumour became markedly decompressed thus facilitating easy dissection and removal. It was adherent to right hilar structures, SVC, pericardium, and diaphragm. Cheesy material along with bone, teeth and bunch of hairs and multiple intestinal loops like structures were removed from within and the tumour was resected out completely using sharp and blunt dissection. Tumour wall was dissected meticulously all around its attachment except pericardium. The plane of dissection between tumour and pericardium was not defined so a small portion of the right-sided pericardium was excised to complete the removal. The tumour had multiple septated cavities, and in the lower portion of the tumour, multiple cystic loops resembling gastrointestinal tract were seen (Fig. 3). Right lung, which was almost totally collapsed at the beginning, started to expand with positive pressure ventilation after surgery. Once the mass was removed, the heart herniated through the pericardial defect into the right hemithorax (large space due to collapsed lung) causing significant hypotension.
Fig. 1. (a) Pre op CXR showing large opacified lesion in anterior mediastinum, occupying most op the right hemithorax with contralateral mediastinal shift (block arrows). (b) Post op CXR showing complete removal of mass with expanded lung (arrow heads).
Fig. 2. (a) Coronal, (b) lateral and (c) horizontal cut section of contrast enhanced high resolution computed tomography chest. A large heterogenous solid cystic (black arrow) multiseptated (thin arrow head) lobulated mass lesion (14.5 10.4 19.9 cm) containing areas of soft tissues and fatty attenuation with multiple coarse calcified septal thickening (thin arrow head) is noted in right hemithorax extending from anterior mediastinum with significant contralateral mediastinal shift (a). Thin walled well-defined capsule with calcification (star) is also noted. Superior vena cava is encased in the mass but luminal patency seen. Final diagnosis anterior mediastinal mature teratoma.
Please cite this article in press as: Majumdar G, et al. Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation, J Indian Coll Cardiol. (2016), http://dx.doi.org/10.1016/j.jicc.2016.06.002
G Model
JICC-334; No. of Pages 4 G. Majumdar et al. / Journal of Indian College of Cardiology xxx (2016) xxx–xxx
Fig. 3. Surgical specimen measuring 25 17 8 cm multinodular, multicystic lesion, filled with fluid and pultaceous material with follicles (blue star), bone and cartilages (black star) and intestinal loops were also noted (white star).
Pericardial defect was repaired to prevent cardiac herniation thus ensuring haemodynamic stability to the patient. Apical and basal thoracostomy tubes were placed and wound was closed in layers. Central venous pressure (CVP) came down to normal (9 mmHg) after removal of the teratoma. Follow-up X-ray chest in the first postoperative morning showed total expansion of both the lungs (Fig. 1b). On 5th post-operative day, he developed left sided pneumothorax that was managed with tube thoracostomy. Lung was expanded and there was no visible air leak. Patient was discharged from hospital in a stable condition. On 18th postoperative day patient again came with recurrent left sided pneumothorax and partial collapse of left lung. Tube thoracostomy along with pleurodesis cured this complication. Histopathological examination revealed a benign cystic teratoma with tissues from all the three germ lines along with gastrointestinal organoid differentiation (Fig. 4). He is doing well 6 months after surgery. 3. Discussion Germ cell tumour (GCT) is uncommon tumour that usually arises in the gonads. Extra gonadal sites are very uncommon and include mediastinum, sacrococygeal region and other midline
Fig. 4. Histopathological slide showing intestinal loops with mucosal lining epithelium with glands (arrow), endodermal origin while layers of muscularis propria and smooth muscle (star) derived from mesoderm (haematoxylin and eosin staining, magnification 20).
3
places. Benign teratomas of the mediastinum are rare and account for only 3–12% of mediastinal tumours, which are usually seen in young adults but can occur in any age group. No predisposing condition or associated abnormalities have been recognised in patients developing these tumours.1 A theory was proposed by fine regarding etiopatholgy of extragonadal germ cell tumour. He suggested that there was an error in migration of primitive germ cells along the urogenital ridge (aberrant migration of progenitor germ cells) which explains their extra gonadal locations like mediastinum.6 Benign mediastinal teratomas are usually asymptomatic at the time of presentation. When symptomatic, substernal chest pain and dyspnoea are the most common presentation. Hairs and sebum in the sputum (trichoptysis) though rare, but such a phenomenon is pathognomic of benign mediastinal teratoma and occurs late in the natural history of the disease. Superior vena cava syndrome is also a rare and late manifestation. The radiological features of GCTs are characterised by complex masses with solid, cystic component with variable amount of fluid and calcification. CECT is the imaging modality of choice for germ cell tumours. Surgical excision is the treatment of choice for benign teratoma of the mediastinum. Best surgical approach for such giant tumour is the primary median full sternotomy, although successful resection can also be done by thoracotomy. Full sternotomy provides excellent exposure as well as safe access to all important mediastinal structures, which may be adherent or embedded in such large tumour.7 Surgical removal by thoracotomy may be challenging at times, when the tumour is extremely large, encroaching both thoracic cavity, in paediatric patients, or when it is adherent to vital structures of the mediastinum.7 10–15% patients may require additional procedures as lobectomy and pericardiectomy for complete tumour removal. In this patient, partial pericardiectomy was carried out to release superior vena cava, which was embedded in the tumour mass. Once the tumour was removed and there was a gap in the pericardium, the heart herniated into the right pleural cavity causing sudden onset of hypotension. Large lateral pericardial defect should be repaired, especially in cases, when lung volume is compromised by surgery or disease as was done in this patient. Benign mediastinal teratomas have a histological appearance identical to that of benign teratomas arising in the more common ovarian location. On histological examination, mature tissue from ectodermal, mesodermal and endodermal germ layers are typically present. Mature tissue that recapitulates the histology of any human organ can be found in these tumours but usually the ectodermal component is predominant. There is no interactive coordination among the germ layer components, so there is a disorganised admixture of mature tissue derived from each germinal layer.2 Rare cases of mature teratoma arising from the ovary and sacrococygeal area with organoid structures having different degree of differentiation have been reported earlier.3,4 The presence of organoid structures in which mucosa interacts with smooth muscle tissue to organise complete gastrointestinal tract differentiation as seen in the current case is a very rare finding.5 Malignant transformation of mature teratoma (TMT) is an extremely rare complication of gonadal teratomas, which is a nongerm cell malignant tumour arising from a pre-existing mature teratoma.8 TMT are of two types, namely chemotherapy or radiotherapy induced TMT and naturally occurring TMT. Naturally occurring TMT in mature mediastinal teratomas in the form of adenocarcinoma have been reported in a long standing large tumour.9,10 Occurrence of an adenocarcinoma in the differentiated intestinal loop of this long standing giant mature mediastinal teratoma is a potential threat. Complete excision of the tumour and regular follow-up for recurrence is, therefore, warranted.
Please cite this article in press as: Majumdar G, et al. Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation, J Indian Coll Cardiol. (2016), http://dx.doi.org/10.1016/j.jicc.2016.06.002
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4. Conclusion We present a very large mature mediastinal teratoma with completely developed organoid structure of gastrointestinal tract, which is rare. A well circumscribed large mediastinal mass on X-ray chest, variegated appearance with solid and cystic components with speckled calcification on CECT in a normal healthy young adult with normal tumour markers (AFP and b-HCG) points towards the diagnosis of mature mediastinal teratoma which was confirmed by histopathological examination of the excised specimen. Complete surgical excision was done, which is the treatment modality of choice. Malignant transformation of the mature mediastinal teratoma (adenocarcinoma or sarcoma) is reported rarely. Pneumothorax was seen as an uncommon complication, which required readmission and pleurodesis. Conflicts of interest The authors have none to declare. Acknowledgements Our sincere thanks to Dr Narendra Krishnani, Dept of Pathology, Dr Zaffar Neyaz, Dept of Radiology, Dr Alok Nath, Dept of
Pulmonary Medicine, Sanjay Gandhi Post graduate institute of Medical sciences, Lucknow, for their valuable contribution. References 1. Kufe DW, Pollock RE, Weichselbaum RR, et al. Holland-Frei Cancer Medicine. 6th ed. Hamilton, ON: BC Decker; 2003. 2. Wesselschmidt RL. The teratoma assay: an in vivo assessment of pluripotency. Methods Mol Biol. 2011;767:231–241. 3. Kwon MJ, Nam ES, Cho SJ, et al. Bowel loop in an ovarian tumor: grossly visible, completely developed intestinal loop in mature cystic teratoma of malignant mixed germ cell tumor. Pathol Int. 2009;59:479–481. 4. Aslan A, Karaguzel G, Gelen T, et al. Sacrococygeal teratoma showing organoid differentiation: report of a case. Surg Today. 2003;33:560–563. 5. Takanashi Y, Tajima S, Takahashi T, Shinmura K, Koyama S, Neyatani H. Mediastinal mature teratoma with complete gastrointestinal and bronchial walls. Respirol Case Rep. 2015;3(September (3)):89–91. 6. Fine F, Smith Jr RW, Pachter MR. Primary extra genital choriocarcinoma in the male subject. Case report and review of literature. Am J Med. 1962;32:776. 7. Koga H, Yamataka A, Kobayashi H, Miyamoto H, Lane GJ, Miyano T. Median sternotomy provides excellent exposure for excising anterior mediastinal tumors in children. Pediatr Surg Int. 2005;21(November (11)):864–867. 8. Morinaga S, Nomori H, Kobayashi R, Atsumi Y. Well differentiated adenocarcinoma arising from mature cystic teratoma of the mediastinum (teratoma with malignant transformation). Report of a surgical case. Am J Clin Pathol. 1994;101(April (4)): 531–534. 9. Lin C, Du Y, Li Y, Wang H, Chang J. Superior mediastinal mature cystic teratoma with gastrointestinal adenocarcinoma transformation: report of a case. Oncotarget. 2016;(May). http://dx.doi.org/10.18632/oncotarget.9532. 10. Muramatsu T, Nishii T, Ohmori K, Shiono M. Mature cystic teratoma with malignant transformation to adenocarcinoma. Ann Thorac Surg. 2011;91(June (6)):1971–1973.
Please cite this article in press as: Majumdar G, et al. Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation, J Indian Coll Cardiol. (2016), http://dx.doi.org/10.1016/j.jicc.2016.06.002
JICC-334; No. of Pages 4 Journal of Indian College of Cardiology xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Journal of Indian College of Cardiology journal homepage: www.elsevier.com/locate/jicc
Case Report
Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation Gauranga Majumdar *, Navneet Kumar Srivastava, Surendra Kumar Agarwal, Shantanu Pande, Bipin Chandra Department of Cardiovascular and Thoracic Surgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow 226014, India
A R T I C L E I N F O
A B S T R A C T
Article history: Received 8 May 2016 Accepted 10 June 2016 Available online xxx
A teratoma is a tumour with tissue or organ components resembling normal derivatives of more than one germ layer.1 Anterior mediastinal teratoma with organoid structures is a rare presentation of germ cell tumour. We report a case of such a rare giant tumour (30 15 cm) in a young adult male of 18 years who presented with right-sided chest pain of 3 years duration. Surgical removal is the definitive treatment of a mature anterior mediastinal teratoma. The patient was operated successfully with complete removal of the tumour. As superior vena cava (SVC) was encased in the tumour wall causing SVC syndrome, partial resection of the pericardium was required to free SVC from the tumour. The defect in the Pericardium was repaired to prevent herniation of heart. In the Post-operative period, patient developed recurrent pneumothorax of the left side, which was successfully treated by intercostal tube drainage and pleurodesis. Post resection histopathology examination confirmed mature teratoma with representation from all the three germ layers including organoid differentiation of gastrointestinal tract. ß 2016
Keywords: Germ cell tumour (GCT) Mediastinal teratoma Organoid differentiation Intestinal loop
1. Introduction Most common extra gonadal site of germ cell tumour is the anterior mediastinum. Benign teratoma of mediastinum accounts for 3–12% of mediastinal tumours with approximately equal incidence in both genders.1 A mature teratoma is composed of several foci of mature tissue derived from at least two out of three embryonic germ layers (ectoderm, endoderm, mesoderm) and presence of all the three germ layers is rare.2 The tumour is composed of tissues which are foreign to the organ or anatomic site in which they arise. Usually tissue arising from different germ layer has no correlation in a mature teratoma. The case reported has a very large mature teratoma (30 15 cm) with fully developed gastrointestinal organoid differentiation manifesting as multiple intestinal loops (cystic component of the tumour), which was confirmed by histopathology. Organoid differentiation of anterior mediastinal teratoma has been reported only rarely in English literature, although ovary and sacrococygeal mature teratoma has been occasionally reported to contain different degree of organoid differentiation.3–5 This teratoma was occupying most of the right
* Corresponding author. E-mail address: [email protected] (G. Majumdar).
hemithorax, anterior and middle mediastinum, extending up to left hemi-thorax. Due to its massive size, pressure effect was clearly visible on right lung, which was compressed; into a small non-functional tissue mass; all the great vessels were compressed, particularly superior vena cava, which was embedded in the tumour raising its pressure to 30 mmHg. The heart and mediastinum were shifted to the left. Surgical removal of teratoma is the only definitive treatment, with no role of chemoradiation.1 Large lateral defect in the pericardium, which was required to isolate SVC from tumour mass in this case, was repaired to prevent potential herniation of the heart. Recurrent tension pneumothorax is an uncommon complication following large mediastinal teratoma removal. 2. Case report An 18-year-old boy presented with complaints of right-sided chest heaviness, pain and exertional dyspnoea for last one year. There was no history of cough, fever, weight loss or haemoptysis. Physical examination revealed a bulge in the right hemi thorax with dilated neck veins. Jugular venous pressure was markedly raised. Trachea was shifted to left on palpation. On auscultation, there was no air entry on right side, middle and basal zone; however, breath sounds were diminished in the apex. Breath
http://dx.doi.org/10.1016/j.jicc.2016.06.002 1561-8811/ß 2016
Please cite this article in press as: Majumdar G, et al. Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation, J Indian Coll Cardiol. (2016), http://dx.doi.org/10.1016/j.jicc.2016.06.002
G Model
JICC-334; No. of Pages 4 2
G. Majumdar et al. / Journal of Indian College of Cardiology xxx (2016) xxx–xxx
sounds were normal in the left hemithorax. Other system examination, including external genitalia was normal. Chest X-ray revealed a well circumscribed homogenously opacified mass lesion occupying right hemithorax along with anterior mediastinum, extending up to left hemithorax with near total atelectasis of right lung. Trachea was deviated to left side with normal patency of left main bronchus with multiple area of calcification in the tumour mass (Fig. 1a). Computed tomography scan (CECT) chest revealed a large heterogeneous solid-cystic multiseptated and lobulated mass lesion (14.5 10.4 19.9 cm) containing areas of soft tissue and fatty attenuation, multiple coarse calcifications and calcified septal thickening in right hemithorax and anterior mediastinum (Fig. 2a–c). The giant mass caused significant contralateral mediastinal shift. Superior vena cava was encased by the mass in its upper portion causing partial SVC obstruction. Right pulmonary artery and their branches and pulmonary vein were compressed within the collapsed lung. Aorta was displaced leftward by the mass. Right lung appeared compressed and collapsed with some amount of aerated parenchyma noted in right apical region. Trachea and oesophagus were normal. Ultra sound examination of abdomen and external genitalia did not reveal any abnormality. All laboratory investigations along with tumour markers such as a-fetoprotein (AFP) and b-human chorionic gonadotropins (b-HCG) were normal. A CT guided fine needle aspiration cytology was suggestive of benign teratoma.
A primary median sternotomy was carried out, which provided excellent exposure of the tumour, and also allowed safe dissection of all mediastinal structures adherent to the tumour. The tumour was occupying most of the right thoracic cavity, anterior mediastinum and reaching up to medial one third of left thoracic cavity. A small incision was given on the tumour to allow the suction tip catheter to enter the cavity over a purse string suture. Copious pultaceous liquid material was sucked out from the tumour. The tumour became markedly decompressed thus facilitating easy dissection and removal. It was adherent to right hilar structures, SVC, pericardium, and diaphragm. Cheesy material along with bone, teeth and bunch of hairs and multiple intestinal loops like structures were removed from within and the tumour was resected out completely using sharp and blunt dissection. Tumour wall was dissected meticulously all around its attachment except pericardium. The plane of dissection between tumour and pericardium was not defined so a small portion of the right-sided pericardium was excised to complete the removal. The tumour had multiple septated cavities, and in the lower portion of the tumour, multiple cystic loops resembling gastrointestinal tract were seen (Fig. 3). Right lung, which was almost totally collapsed at the beginning, started to expand with positive pressure ventilation after surgery. Once the mass was removed, the heart herniated through the pericardial defect into the right hemithorax (large space due to collapsed lung) causing significant hypotension.
Fig. 1. (a) Pre op CXR showing large opacified lesion in anterior mediastinum, occupying most op the right hemithorax with contralateral mediastinal shift (block arrows). (b) Post op CXR showing complete removal of mass with expanded lung (arrow heads).
Fig. 2. (a) Coronal, (b) lateral and (c) horizontal cut section of contrast enhanced high resolution computed tomography chest. A large heterogenous solid cystic (black arrow) multiseptated (thin arrow head) lobulated mass lesion (14.5 10.4 19.9 cm) containing areas of soft tissues and fatty attenuation with multiple coarse calcified septal thickening (thin arrow head) is noted in right hemithorax extending from anterior mediastinum with significant contralateral mediastinal shift (a). Thin walled well-defined capsule with calcification (star) is also noted. Superior vena cava is encased in the mass but luminal patency seen. Final diagnosis anterior mediastinal mature teratoma.
Please cite this article in press as: Majumdar G, et al. Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation, J Indian Coll Cardiol. (2016), http://dx.doi.org/10.1016/j.jicc.2016.06.002
G Model
JICC-334; No. of Pages 4 G. Majumdar et al. / Journal of Indian College of Cardiology xxx (2016) xxx–xxx
Fig. 3. Surgical specimen measuring 25 17 8 cm multinodular, multicystic lesion, filled with fluid and pultaceous material with follicles (blue star), bone and cartilages (black star) and intestinal loops were also noted (white star).
Pericardial defect was repaired to prevent cardiac herniation thus ensuring haemodynamic stability to the patient. Apical and basal thoracostomy tubes were placed and wound was closed in layers. Central venous pressure (CVP) came down to normal (9 mmHg) after removal of the teratoma. Follow-up X-ray chest in the first postoperative morning showed total expansion of both the lungs (Fig. 1b). On 5th post-operative day, he developed left sided pneumothorax that was managed with tube thoracostomy. Lung was expanded and there was no visible air leak. Patient was discharged from hospital in a stable condition. On 18th postoperative day patient again came with recurrent left sided pneumothorax and partial collapse of left lung. Tube thoracostomy along with pleurodesis cured this complication. Histopathological examination revealed a benign cystic teratoma with tissues from all the three germ lines along with gastrointestinal organoid differentiation (Fig. 4). He is doing well 6 months after surgery. 3. Discussion Germ cell tumour (GCT) is uncommon tumour that usually arises in the gonads. Extra gonadal sites are very uncommon and include mediastinum, sacrococygeal region and other midline
Fig. 4. Histopathological slide showing intestinal loops with mucosal lining epithelium with glands (arrow), endodermal origin while layers of muscularis propria and smooth muscle (star) derived from mesoderm (haematoxylin and eosin staining, magnification 20).
3
places. Benign teratomas of the mediastinum are rare and account for only 3–12% of mediastinal tumours, which are usually seen in young adults but can occur in any age group. No predisposing condition or associated abnormalities have been recognised in patients developing these tumours.1 A theory was proposed by fine regarding etiopatholgy of extragonadal germ cell tumour. He suggested that there was an error in migration of primitive germ cells along the urogenital ridge (aberrant migration of progenitor germ cells) which explains their extra gonadal locations like mediastinum.6 Benign mediastinal teratomas are usually asymptomatic at the time of presentation. When symptomatic, substernal chest pain and dyspnoea are the most common presentation. Hairs and sebum in the sputum (trichoptysis) though rare, but such a phenomenon is pathognomic of benign mediastinal teratoma and occurs late in the natural history of the disease. Superior vena cava syndrome is also a rare and late manifestation. The radiological features of GCTs are characterised by complex masses with solid, cystic component with variable amount of fluid and calcification. CECT is the imaging modality of choice for germ cell tumours. Surgical excision is the treatment of choice for benign teratoma of the mediastinum. Best surgical approach for such giant tumour is the primary median full sternotomy, although successful resection can also be done by thoracotomy. Full sternotomy provides excellent exposure as well as safe access to all important mediastinal structures, which may be adherent or embedded in such large tumour.7 Surgical removal by thoracotomy may be challenging at times, when the tumour is extremely large, encroaching both thoracic cavity, in paediatric patients, or when it is adherent to vital structures of the mediastinum.7 10–15% patients may require additional procedures as lobectomy and pericardiectomy for complete tumour removal. In this patient, partial pericardiectomy was carried out to release superior vena cava, which was embedded in the tumour mass. Once the tumour was removed and there was a gap in the pericardium, the heart herniated into the right pleural cavity causing sudden onset of hypotension. Large lateral pericardial defect should be repaired, especially in cases, when lung volume is compromised by surgery or disease as was done in this patient. Benign mediastinal teratomas have a histological appearance identical to that of benign teratomas arising in the more common ovarian location. On histological examination, mature tissue from ectodermal, mesodermal and endodermal germ layers are typically present. Mature tissue that recapitulates the histology of any human organ can be found in these tumours but usually the ectodermal component is predominant. There is no interactive coordination among the germ layer components, so there is a disorganised admixture of mature tissue derived from each germinal layer.2 Rare cases of mature teratoma arising from the ovary and sacrococygeal area with organoid structures having different degree of differentiation have been reported earlier.3,4 The presence of organoid structures in which mucosa interacts with smooth muscle tissue to organise complete gastrointestinal tract differentiation as seen in the current case is a very rare finding.5 Malignant transformation of mature teratoma (TMT) is an extremely rare complication of gonadal teratomas, which is a nongerm cell malignant tumour arising from a pre-existing mature teratoma.8 TMT are of two types, namely chemotherapy or radiotherapy induced TMT and naturally occurring TMT. Naturally occurring TMT in mature mediastinal teratomas in the form of adenocarcinoma have been reported in a long standing large tumour.9,10 Occurrence of an adenocarcinoma in the differentiated intestinal loop of this long standing giant mature mediastinal teratoma is a potential threat. Complete excision of the tumour and regular follow-up for recurrence is, therefore, warranted.
Please cite this article in press as: Majumdar G, et al. Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation, J Indian Coll Cardiol. (2016), http://dx.doi.org/10.1016/j.jicc.2016.06.002
G Model
JICC-334; No. of Pages 4 4
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4. Conclusion We present a very large mature mediastinal teratoma with completely developed organoid structure of gastrointestinal tract, which is rare. A well circumscribed large mediastinal mass on X-ray chest, variegated appearance with solid and cystic components with speckled calcification on CECT in a normal healthy young adult with normal tumour markers (AFP and b-HCG) points towards the diagnosis of mature mediastinal teratoma which was confirmed by histopathological examination of the excised specimen. Complete surgical excision was done, which is the treatment modality of choice. Malignant transformation of the mature mediastinal teratoma (adenocarcinoma or sarcoma) is reported rarely. Pneumothorax was seen as an uncommon complication, which required readmission and pleurodesis. Conflicts of interest The authors have none to declare. Acknowledgements Our sincere thanks to Dr Narendra Krishnani, Dept of Pathology, Dr Zaffar Neyaz, Dept of Radiology, Dr Alok Nath, Dept of
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Please cite this article in press as: Majumdar G, et al. Giant anterior mature mediastinal teratoma with gastrointestinal tract organoid differentiation: A rare presentation, J Indian Coll Cardiol. (2016), http://dx.doi.org/10.1016/j.jicc.2016.06.002