Immature teratoma of the nose and paranasal sinuses masquerading as bilateral nasal polyposis: A unique presentationSK Aggarwal1, A Keshri1, P Agarwal2
1 Department of Neurosurgery, SGPGIMS, Lucknow,Uttar Pradesh, India
2 Department of Pathology, SGPGIMS, Lucknow,Uttar Pradesh, India
Teratomas are tumors of multipotent cells derived from all three germ cell layers and recapitulate normal organogenesis. Teratomas are hypothesized to arise by misplacement of multipotent germ cells. Teratoma is usually developmental and sometimes congenital neoplasm which displays both solid and cystic components with gross and microscopic differentiation into a wide variety of tissues representative of all three germ layers-ectoderm, mesoderm and endoderm. We are describing a case which was initially diagnosed as bilateral nasal polyposis clinically but histopathology report came out to be immature teratoma. This case is being reported to make aware all ENT surgeons of such unique presentation of sinonasal teratomas as such presentation of these tumors has not been reported in literature previously, and hence teratomas should be considered in the differential diagnosis of nasal polyposis in future.
Keywords: Immature teratoma, nasal polyposis, unique presentation
By definition, teratomas are tumors of multipotent cells derived from all three germ cell layers and recapitulate normal organogenesis. Teratomas are hypothesized to arise by misplacement of multipotent germ cells. Broadly, these are classified as mature, immature and malignant. Age range at presentation varies from birth to 6 th decade of life. 
The immature form of teratoma was first described in 1960 by Thürlbeck and Scully.  It is found either in pure form or as a component of a mixed germ cell tumor. According to WHO, immature teratoma (IT) is defined as a teratoma containing a variable amount of immature embryonal type (generally) neuroectodermal tissue. 
Teratoma is usually developmental and sometimes congenital neoplasm which displays both solid and cystic components with gross and microscopic differentiation into a wide variety of tissues representative of all three germ layers ectoderm, mesoderm and endoderm.The presence of tissues within the lesion that are foreign to the affected sites is a distinctive feature of this rare tumor. The epithelial component of a benign teratoma usually consists of mature squamous epithelium and immature intestinal or respiratory epithelium. Primitive neuroepithelium with rosettes, pseudorosettes or neurofibrillary matrix predominates in some tumors. Pigmented retinal epithelium can also be seen. The mesodermal component consists of fibroblasts and embryonic, immature spindle cells embedded in a myxoid matrix. Islands of cartilage, smooth muscle cells, and skeletal muscle cells exhibiting varying degrees of maturity may also be present. 
The incidence of teratomas is 1:4000 births, with the sacrococcygeal area being the most common site.  Teratomas of the head and neck are extremely rare and usually seen during the neonatal period, which account for less than 2% of reported cases of congenital teratomas. Teratomas of the head and neck are most commonly found in the cervical neck.  Calcification within the mass is often evident. Sinonasal teratomas mostly present with nasal obstruction symptoms. 
We are describing a case which was initially misdiagnosed as bilateral nasal polyposis but it was only through histopathological examination (HPE) that the tumor was diagnosed as IT. Hence, we are reporting this case to make ENT surgeons aware of such unique presentation of sinonasal teratomas as such presentation of these tumors has not been reported in literature previously.
A thirty five year old male patient presented to our tertiary care institute with chief complaints of bilateral nasal obstruction for last 6 months and left eye proptosis and diplopia for last 1 month [Figure 1]. There was no history of nasal bleeding or decreased vision. Patient also had complaints of intermittent headache with posterior nasal drip. There was no hisory of any co-morbid illness in the patient. Patient had been operated at a district hospital for nasal mass around 2 months back and the histopathology report came out to be nasal polyposis. But as patient did not have any relief in nasal obstruction, he was referred to our hospital for further management. On examination, bilateral pale fleshy polyps were seen in nasal cavity on anterior rhinoscopy, not bleeding on touch. Left eye proptosis with conjunctival chemosis was also present but eyeball movements were full in all directions and vision was more than 6 feet in both the eyes. Pupils were normal and reacting to light. In view of bilateral nasal polyps along with left eye proptosis and to diagnose the type of pathology, contrast enhanced computed tomography (CECT) of paranasal sinuses, nose and orbit was done. CT scan showed non-enhancing bilateral nasal mass extending in all the sinuses with nasopharyngeal extension.There was minimal erosion of left lamina papyracea with minimal extension of nasal mass in left orbit [Figure 2]. Patient was planned for endoscopic nasal debridement under general anesthesia after provisional diagnosis of nasal polyposis was made. Intra-operatively, the mass was not looking like nasal polyps as the colour of the mass was reddish-brown but it was not bleeding much. Bilateral nasal cavity, paranasal sinuses and nasopharynx was debrided as much as we can and the tissue was sent for histopathological examination (HPE). The nasal cavity was packed with medicated ribbon gauze. HPE report, to our surprise, came out to be immature teratoma. Microscopic features of the tumor were displaying all germ cell layers with presence of squamous epithelial lined cystic structure, respiratory epithelium lined primitive neuroepithelium, glandular structures, mature cartilage and areas of haemorrhage in stromal component [Figure 3]. Radiotherapy consultation was sought for post-operative chemotherapy as immature teratoma is considered to be sensitive to chemotherapy. Post-chemotherapy, repeat CT was done which showed no residual or recurrence of disease. Patient is on regular follow-up with us for last 3 months without any complaints.
To make the diagnosis of teratoma, it is mandatory to find at least two of three germ layers.  The ectoderm tissue generally is predominant and is composed of neural tissues, skin, hair, and teeth. Mesodermic tissues such as fat, cartilage, or bone and endodermic tissue are less common. The endoderm layer is characterized by respiratory or intestinal epithelia.  Immature teratomas (IT) are usually derived from a malignant transformation of mature teratomas.  The amount of neuroectodermal immature tissue present permits the classification of immature teratomas into three grades of increasing malignancy. 
Teratomas can occur in any region of the body, commonly in the paraxial and midline location.  Teratomas of the head and neck are extremely rare and these occur in these locations in nearly 1-3.5% of all cases.  The common sites of involvement being the neck, oropharynx, nasopharynx, orbit, and paranasal sinuses.  Strictly speaking, head and neck teratomas are very rare and the localization in the nasal cavity is very unusual.  Most of the reported cases are of nasopharyngeal and cervical origin.  Head and neck teratomas are usually located anteriorly and laterally; however, there have been a few cases in which the teratoma is located in the occipitocervical region. 
Generally, teratomas are more common in females than males. However, it has been established that there is no sex predilection in head and neck teratomas.  Most of the cases occur in neonates and older infants, contrary to our patient who was male and was of adult age-group. As a general rule, while pediatric teratomas of the head and neck tend to be oncologically benign, adult teratomas tend to be histologically and oncologically malignant contrary to our case in which the HPE report was immature teratoma despite being an adult patient. ,
Immature teratomas of the sinonasal tract are rare. In the sinonasal tract, the maxillary antrum and nasal cavity are affected more often than the sphenoid sinus. In our patient, all the sinuses were equally involved by the tumor. Common manifestations of sinonasal teratomas include facial deformity, nasal obstruction, and a nasal mass.  In our patient, the main manifestation was bilateral nasal obstruction with left eye proptosis.
Teratoid tumors of the nasopharynx comprise an uncommon group of neoplasms. In the upper respiratory tract, they present as dermoid cyst, commonly at nasal region, but in the nasopharynx and oropharynx, they have been called as 'hairy polyps' as they are covered by hairy skin and are solid polypoidal lesions unlike dermoid cyst.  In 1918, Brown-Kelly was credited for the first report of 'hairy polyp'. 
The following should be considered in the differential diagnosis of sinonasal teratomas: Immature teratomas, teratomas with malignant transformation, sinonasal yolk sac tumors, sinonasal teratocarcinosarcomas, dermoid cysts, hamartomas, and hairy polyps. Immature teratomas are tumors of infancy and early childhood contrary to our case which occurred in an adult patient, whereas sinonasal yolk sac tumors and sinonasal teratocarcinosarcomas have only been documented in adults. ,,
Teratomas may be histologically mature and oncologically benign. Teratomas may also be histologically immature while being oncologically benign, or they may harbor malignant components and have the potential to exhibit an aggressive biological behaviour. A mature teratoma is typically benign and is found more commonly in females, but immature teratomas are typically malignant and are found more often in males.  Histologically, the latter contain immature elements, such as immature neuroepithelium or immature mesenchymal tissue.  There are three main histological types of teratomas which include mature (benign), immature (malignant) and monodermal (highly specialized) teratomas.  Mature teratomas contain well differentiated cells, while immature teratomas contain primitive structures that are not adequately differentiated. Teratomas that contain a malignant component are classified as malignant teratoma.  Immature teratomas tend to be either solid-nodular or solid cystic, while mature teratomas are usually cystic.  Cystic teratomas are mostly benign, containing sebaceous materials and mature tissue types. On the other hand, solid teratomas are usually malignant and composed of immature embryonic tissues in addition to adipose, cartilaginous, fibrosis and bony components. 
The only type of neural tissue that should be counted in grading a tumor for immaturity is primitive neural tubes and immature rosettes.  According to a review article by Ulbright,  fetal type tissue (immature mesenchyme) alone is not sufficient for a diagnosis of IT. Immature mesenchyme is defined as sparsely cellular, loose, primitive mesenchymal tissue with mitotic figures. 
Teratoma shows some tissue calcification in about 16% of cases.  The calcification depicts the presence of highly mineralized well differentiated tissues, including teeth and bones. Histopathological examination (HPE) remains the gold standard for the confirmation of this lesion similar to our case which was only diagnosed by HPE. 
Preoperative CT and MRI are imperative to rule out intracranial extension of the tumours. , These imaging techniques aid in demonstrating the relationship of the lesion to surrounding vascular, bony and visceral structures. MRI was not done in our case as clinically we had made a diagnosis of nasal polyposis which was proved to be immature teratoma only on HPE.
The recommended management for head and neck teratomas is surgical excision. This is curative and recurrence is rare.  Transoral endoscopic removal of lesions located in the nasopharynx has been described, and this approach provides direct visualisation of the mass at its base.  Complete surgical excision is effective for children with immature teratomas with or without malignant elements and salvage chemotherapy has been successful in those with recurrent disease as this tumor is highly chemosensitive. , Sinonasal teratomas are associated with high mortality rates, despite the utilization of different modalities in the treatment. Conservative treatment of immature teratoma is possible, and does not seem to influence recurrence and survival rates. Patients with more advanced stage disease should be treated with adjuvant chemotherapy containing bleomycin, etoposide and cisplatin in addition to surgery. 
Thus, we conclude that sinonasal teratomas are very rare but they should be considered in the differential diagnosis of nasal polyposis as the presentation can be remarkably similar in both of them. Also, in every case of nasal polyposis, tissue should be sent for HPE as teratomas can only be diagnosed by HPE and hence, ENT surgeons would not miss such unique presentations of sinonasal teratomas in future.
We would like to acknowledge the contribution of our patient in this manuscript, who has given his written consent to publish his photograph for this manuscript or for any other academic purposes.
[Figure 1], [Figure 2], [Figure 3]