|Year : 2016 | Volume
| Issue : 1 | Page : 41-43
Mature cystic teratoma of mediastinum with pleural effusion: An uncommon entity
Gautam Mandal, Somnath Bhattacharya, Atin Dey, Saurav Kar, Sayantan Saha
Department of Pulmonary Medicine, R. G. Kar Medical College, Kolkata, West Bengal, India
|Date of Web Publication||13-Apr-2016|
Department of Pulmonary Medicine, R. G. Kar Medical College, Kolkata, West Bengal
Source of Support: None, Conflict of Interest: None
Teratomas are tumours composed of tissues originating from at least two of the three primitive germ layers, i.e., ectoderm, mesoderm and endoderm. A dermoid cyst, commonly known as benign cystic teratoma is a histological variant containing epidermis and its derivative (sebaceous material) within a lining of squamous epithelium. Mediastinum is the most common extragonadal site for germ cell tumours including mature teratomas. However, pleural effusion secondary to rupture of benign germ cell tumour is quite a rarity and the nature of pleural effusion in such ruptured cases has not been discussed in detail in literatures. Here, we are presenting a case of mature cystic teratoma coexistent with pleural effusion which is quite an uncommon entity making this case quite an interesting learning curve.
Keywords: Mediastinal space occupying lesion, mediastinal teratoma, pleural effusion
|How to cite this article:|
Mandal G, Bhattacharya S, Dey A, Kar S, Saha S. Mature cystic teratoma of mediastinum with pleural effusion: An uncommon entity. Niger Postgrad Med J 2016;23:41-3
|How to cite this URL:|
Mandal G, Bhattacharya S, Dey A, Kar S, Saha S. Mature cystic teratoma of mediastinum with pleural effusion: An uncommon entity. Niger Postgrad Med J [serial online] 2016 [cited 2019 Oct 18];23:41-3. Available from: http://www.npmj.org/text.asp?2016/23/1/41/180183
| Introduction|| |
Teratomas are the most common germ cell tumours. By definition, they are made up of tissues foreign to the area in which they occur.  They arise from the remnant multipotent germ cells that show abnormal migration during embryonic development.  Embryologically, they originate from the third pharyngeal pouch. Mediastinal teratomas constitute about 8-13% of all mediastinal tumours. This case is noteworthy for predicting a strong clinical suspicion to identify teratomas as likely aetiology in undiagnosed cases of pleural effusion.
| Case Report|| |
A 28-year-old non-diabetic non-hypertensive female patient residing at a rural part of West Bengal presented at our Tertiary Care Hospital R. G. Kar Medical College, Kolkata, West Bengal, India with complaints of gradually progressive shortness of breath (modified Medical Research Council grade 2 at presentation) , along with heaviness of chest and low grade fever for last 1 month. There was no seasonal or diurnal variation of dyspnoea, no history of wheeze, allergic rhinitis or suggestive features of paroxysmal nocturnal dyspnoea and orthopnoea. The patient had an intermittent low-grade fever, not associated with episodes of chills and rigor, but relieved by antipyretic medication. There was a single episode of scanty haemoptysis around 15 days back which subsided spontaneously. However, there was no history of persistent cough or chest pain but had unmeasured weight loss and loss of appetite during this period.
On the general survey, she was thin built with poor nutritional status. Pallor was present, but no cyanosis, clubbing or peripheral lymphadenopathy. The patient was febrile, respiratory rate 24/min. Examination of the respiratory system showed diminished vesicular breath sound over left mammary, inframammary, infraaxillary area with dull note on percussion in the corresponding areas. Examination of other systems was normal.
Blood examination showed anaemia (haemoglobin 8.6 g%), high erythrocyte sedimentation rate 82 mm/h and normal white blood cell count 7900/mm 3 . Blood biochemistry was normal, and HIV and hepatitis viral markers were nonreactive. Chest radiography [Figure 1] showed homogenous opacity over left hemithorax, occupying portion of upper zone, whole of the mid and lower zone, except the lateral side, with sharp margin. Laterally, it has lobulated appearance, and medially it merges with mediastinum, however, there is no shifting of mediastinum. Contrast enhanced computed tomography (CT) thorax [Figure 2] showed a lobulated cystic space occupying lesion (SOL) measuring 112 mm × 96 mm × 167 mm in anterior and lateral part of entire left hemithorax with a thick wall and irregular calcification along with left sided mild pleural effusion.
|Figure 1: Chest radiography showed homogenous opacity over left hemithorax, occupying portion of upper zone, whole of the mid and lower zone, except the lateral side, with sharp margin. Laterally, it has lobulated appearance and medially it merges with mediastinum, however, there is no shifting of mediastinum|
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|Figure 2: Contrast enhanced computed tomography thorax showing a lobulated cystic space occupying lesion measuring 112 mm × 96 mm × 167 mm in anterior and lateral part of entire left hemithorax with thick wall and irregular calcification along with left sided mild pleural effusion|
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CT-guided aspirate from the cystic lesion revealed greyish pus such as a material with Gram-stain, Ziehl-Neelsen stain, pyogenic culture and mycobacterial culture all being negative. Scolex and hooklet of echinococcus could not be demonstrated. Whereas the aspirated pleural fluid was exudative, with degenerated cells, adenosine deaminase 26.6 IU/L, amylase level 210 IU/L, and malignant cell block was negative. We kept in mind the following possibilities (a) infected hydatid cyst (b) lung abscess (c) a malignant SOL.
The fibreoptic bronchoscopy revealed normally moving vocal cord, sharp carina with evidence of external compression over the left main bronchus downward. The right bronchial system was normal and no intrabronchial mass or inflammation seen bilaterally. Blood for serum alpha-fetoprotein, beta human chorionic gonadotrophin and serum lactate dehydrogenase were normal.
Thereafter, we had referred the case to our cardiothoracic surgery department for excision biopsy for confirmation of diagnosis. Patient underwent left anterolateral thoracotomy with debulking of mediastinal mass under endobronchial anaesthesia. Excised lesion showed multiple pieces of thick walled cyst containing cheesy material and hair along with a greyish tissue with yellow fatty area, cartilaginous tissue and bone fragments. Histopathology of the excised mass [Figure 3] showed ectodermal, mesodermal and endodermal elements with the presence of skin and its appendages, spicules of bone, cartilage, lymphoid tissue, mucin-secreting glands and mature adipose tissue. Shafts of hair, cholesterol clefts surrounded by foamy macrophages along with focal collection of histiocyte and foreign body giant cells were present. Hence, the final diagnosis was mature cystic mediastinal teratoma with left sided pleural effusion.
|Figure 3: Histopathology of excised mass showing ectodermal, mesodermal and endodermal elements with presence of skin and its appendages, cartilage, lymphoid tissue, mucin secreting glands and mature adipose tissue|
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Post-operatively patient improved clinically and radiologically [Figure 4] and [Figure 5]. Her dyspnoea and chest pain had reduced, and chest radiography showed reduced size of the mass (measuring 34 mm × 16 mm × 63 mm) with complete resolution of left-sided pleural effusion. Patient is on regular follow-up at our chest department and responding well.
|Figure 4: Post-operative chest radiograph showing near total expansion of the left lung with intercostals tube in situ for drainage|
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|Figure 5: Post-operative computed tomography thorax confirming left lung expansion with no evidence of pleural effusion|
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| Discussion|| |
The first case of pulmonary teratoma was reported by Mohr way back in 1839. Anterior mediastinum is the most common extragonadal site for germ cell tumour , and mature teratomas are the most common histological type of primary mediastinal germ cell tumour.  Teratomas are derived from at least two of the three primitive germ layers. Differentiation into mature (benign) and immature (malignant) teratomas are based upon the cell of origin. Microscopically mature teratomas contain well-differentiated ectodermal (skin, hair, sweat glands and tooth), mesodermal (fat, cartilage, bone and smooth muscle) as well as endodermal (respiratory and intestinal epithelium) elements in varying proportion.  Whereas malignant teratomas contain foetal and neuroendocrine tissue (immature elements). A dermoid cyst (benign cystic teratoma) is a variant that contains epidermis and its derivative (sebaceous material) within a lining of squamous epithelium. 
Teratomas are most common in young adults. About one-third of the patients remain asymptomatic  whereas symptoms develop when the cysts become infected and erode into the pleural (respiratory distress and chest pain) or pericardial space (cardiac tamponade) or bronchus (haemoptysis, trichoptysis or expectoration of sebaceous material). 
Radiologically, cystic teratomas are generally smooth, rounded and well circumscribed, whereas solid varieties are more lobulated and asymmetrical.  CT scan may clearly identify soft tissue, fat and calcification (even fully formed teeth and bone), rendering this one of the few mediastinal tumours that can be diagnosed with confidence pre-operatively. 
All teratoma should be resected because they may be malignant, and even if benign they may enlarge impinging upon adjacent vital structures.  If completely resected, benign lesions do not require any post-operative radiation with an average disease-free interval of 10 years. 
Interestingly pleural effusion resulting from rupture of a benign germ cell tumour is quite a rare occurrence. , Study by Choi et al.  of over 17 patients revealed pre-operative rupture with concomitant pleural effusion in <25% patients. No elaborated report is available regarding the nature of pleural effusion in such ruptured cases. Some cases showed elevated pleural fluid level carcinoembryonic antigen,  some revealed elevated amylase level. However, no conclusive descriptions were provided.  Our case showed exudative pleural effusion with a marginal elevation of amylase level. Henceforth, our case was noteworthy in the perspective of the factors that strong clinical suspicion is required for predicting mature cystic mediastinal teratoma as a potential aetiology for undiagnosed pleural effusion.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]