Germ Cell Tumors
Germ cell tumors are rare in the head and neck, and histologically are almost identical to those that arise in the gonads (Table 16.1).
Immature Teratoma
(ICD-O code 9080/3)
Incidence and Site
Teratomas are not uncommon tumors in children, but the vast majority arise in the sacrococcygeal area and Tapper and Lack1 reviewing a 54-year experience from a children′s hospital in Boston, Massachusetts, found only 5% of the tumors arising in the head and neck from a total of 254 patients. None arose from the sinonasal region and only a single case from the nasopharynx. Further cases of nasopharyngeal teratoma have been described2,3 and additionally two in the maxillary sinus4 and in the ethmoid sinus5 and sphenoid sinus.6
The subsequent appearance of both embryonal carcinoma7 and squamous cell carcinoma8 arising in inadequately resected immature teratomas has been reported. Lack′s review of 16 cases in the head and neck details four large tumors that involve both oropharynx and nasopharynx and adjacent tissues. One of these cases was attached by a narrow stalk to the posterior nasal septum and presented as a polypoidal mass passing through the nasopharynx and into the oropharynx as far inferiorly as the laryngeal inlet.
Diagnostic Features
Clinical Features
Teratoma is most commonly seen in newborn children as, by the time of birth, they have often attained a significant size to produce either a visible mass or symptoms related to the site of origin, such as respiratory distress, feeding difficulties, and dysphagia. An emergency tracheostomy is frequently necessary in the neonates with the larger cervical tumors and those affecting the oropharynx and nasopharynx.
Immature teratomas | ICD-O 9080/3 |
Teratoma with malignant transformation | ICD-O 9084/3 |
Sinonasal yolk sac tumor | ICD-O 9071/3 |
Sinonasal teratocarcinoma | No ICD-O code |
Mature teratoma | ICD-O 9080/0 |
Dermoid cyst | ICD-O 9084/0 |
Histological Features
Teratomas of the head and neck have been reported in a large range of sizes ranging from 3 to 11 cm in diameter and may be solid or cystic. Those involving the sinonasal tract and nasopharynx have been described as containing mature and immature tissues from the three embryonic germ layers, and the variable immature element is mostly neuroepithelial. In addition to the primitive neuroepithelial tissue, the cystic spaces may be lined with ciliated pseudostratified epithelium. Cellular atypia are not common, although mitotic figures are usually seen in the immature areas. Immature teratomas are rarely malignant but, as mentioned above, malignant transformation has to be excluded, particularly following inadequate treatment.
Treatment and Prognosis
The general recommendation for treatment of germ cell malignancies in all sites of the body is for complete surgical resection when possible. Both the treatment and prognosis ultimately depend on the age of the patient, the site of involvement, and the tumor histology. Examples of immature and mature teratoma tissue in cervical lymph nodes have been described, but it does not seem to alter the favorable prognosis if complete surgical resection is achieved. The pathologist has an important role in germ cell tumors of accurate determination of histological grade, adequate resection, and the presence or absence of unfavorable histological elements such as embryonal carcinoma. However, in neonates and infants, the histological grade of immature teratomas arising in the head and neck region does not seem to be a reliable predictor of biological behavior.
Teratoma with Malignant Transformation
(ICD-O code 9084/3)
In the sinonasal tract and nasopharynx, teratomas with malignant transformation are extremely rare. This neoplasm has a somatic malignancy in addition to benign tissue elements of all three germinal layers and, as described above, both embryonal carcinoma5 and squamous carcinoma6 have been reported. These cases require adjuvant treatment with radiotherapy and chemotherapy on an individual basis in relation to the site, extent, and type of malignancy.
Sinonasal Yolk Sac Tumor (Endodermal Sinus Tumor)
(ICD-O code 9071/3)
These extremely rare tumors in the sinonasal tract have identical histology to the yolk sac tumor (endodermal sinus tumor) of the gonads. The two reported cases have occurred in adults aged 34 and 43 years. In one of these adult cases, there was an accompanying area of sinonasal nonkeratinizing carcinoma.
Sinonasal Teratocarcinosarcoma
Definition
(No ICD-O code)
As the name implies, this is a malignant sinonasal lesion with features of both teratoma and carcinosarcoma. Most commonly, it has both epithelial elements which are benign as well as malignant. There are mesenchymal and neural elements including blastomatous immature tissues. Seminoma, embryonal carcinoma, and choriocarcinoma features are absent.
Etiology
There are no known etiological factors and, contrary to the tumor currently being classified under germ cell tumors, recent work would suggest that it is unlikely to be of germ cell origin. In a detailed analysis of the ultrastructural and immunohistochemical evidence, Shimazaki et al9 feel that sinonasal teratocarcinoma is essentially a neuroectodermal tumor with a capacity to differentiate into divergent types of somatic cells.
Incidence and Site
There are ~60 cases to date in the literature, with the vast majority arising in the nasal cavity with the ethmoid and maxillary sinuses subsequently involved. The tumor has a marked male predominance and is exclusive to adults, being described up to an age of 79 years.10–16
Diagnostic Features
Clinical Features
The commonest symptoms at presentation are nasal obstruction and epistaxis; in contrast to many other tumors within the sinonasal area, the duration of symptoms in these patients is often short. In the study by Heffner et al10 of 20 cases, the duration of symptoms ranged from 2 to 10 weeks. Only two of their patients complained of pain or headache, and only one was associated with proptosis. On examination, the nasal masses have been described as being moderately firm, red to red-purple, with friable and necrotic areas in some cases. Bleeding in association with examination was common.
Imaging
CT and MRI reveal a soft tissue mass with surrounding bony destruction, but no particular imaging features of note.
Histological Features
These tumors show a complex histological pattern with mature and immature glands, benign squamous and malignant poorly differentiated epithelium, and neuroepithelial elements, often with rosettes and neuroblastomalike areas. The mesenchymal areas may range from immature tissues such as cartilage to sarcomas, notably with rhabdomyoblastic differentiation and elements akin to fibrosarcoma. There may be additional small round cells that are difficult to classify.
Immunohistochemical Features
As might be expected in a tumor containing so many different elements, the reported immunohistochemical findings vary considerably, but in general the primitive cells are often positive for cytokeratin, epithelial membrane antigen, vimentin, and neurospecific enolase. The rhabdomyoblast components are positive for desmin, muscle actin (HHF35), α smooth muscle actin, myoglobin, and cytokeratin. Components of squamous cell differentiation may be positive for cytokeratin, epithelial membrane antigen, and neuron-specific enolase. MyoD1 and myogenin may be expressed in the primitive cells, glandular cells, and rhabdomyoblasts. The stroma may contain a small number of S100-positive cells.
Differential Diagnosis
As with so many rare tumors, inadequate biopsy may lead to incorrect diagnosis and the possibilities with this tumor are wide-ranging, varying from olfactory neuroblastoma, undifferentiated carcinoma, adenocarcinoma, malignant salivary gland–type tumors, and adenosquamous carcinoma. Adequate biopsy material is absolutely essential and may require a general anesthetic to allow sufficient material to be obtained.
Treatment and Prognosis
These lesions are highly malignant, presenting with short histories, and are quickly locally aggressive, invading bone, soft tissue, the orbit, the skull base, and the intracranial compartment.16 The oft-quoted figures of survival from Heffner′s clinicopathological study of 20 cases reported in 198410 are that the average survival is <2 years, with 60% of patients not surviving beyond 3 years. Spread to regional lymph nodes and distant sites, particularly the lungs, is described in publications from the 1980s and 1990s. However, what is significant in evaluating papers from this period is that these patients have not been treated with complete resection by modern craniofacial surgery followed by appropriate radical radiotherapy plus or minus chemotherapy. It is possible that earlier and accurate diagnosis of the tumor combined with complete resection and postoperative radiotherapy might improve the treatment outcome in these patients. The clinical effectiveness of chemotherapy in the reported cases cannot be evaluated because of the small numbers of patients and inadequate detail.17
Mature Teratoma
Definition
(ICD-O code 9080/0)
Mature teratomas of the sinonasal area and skull base are similar to the same lesion within the gonads or other gonadal locations. They are composed of varying amounts of mature tissues that are foreign to the sinonasal site and typically contain tissues derived from three germ layers, but occasionally only two.
Etiology
As with other germ cell tumors, the main discussion is whether they are derived from primordial germ cells or primitive somatic cells that have escaped the control of the normal influence of cell organizers and growth factors.1
Synonyms
Benign teratoma and teratoid tumor are the most commonly used synonyms. Hairy polyp and hamartomata have also been used.
Incidence and Site
Teratomas in the head and neck account for ~6% of all teratomas, but mature teratomas in the sinonasal tract are rare. Most of these cases have been described in neonates and older infants with an approximately equal sex distribution.18 These lesions have been associated with maternal polyhydramnios, fetal malpresentation, prematurity, and stillbirth. They may be diagnosed in the antenatal period by routine ultrasonography. The maxillary sinuses are the most frequently affected areas, but cases originating from the sphenoid sinus and nasopharynx have also been reported.6,7,19,20
Diagnostic Features
Clinical Features
Antenatal diagnosis of nasopharyngeal teratomas is uncommon, but the use of antenatal ultrasonography in the diagnosis of various congenital anomalies, especially when the mother presents with polyhydramnios, is well documented. The hydramnios is associated with congenital malformation in ~20% of patients. Eighteen percent of cervical teratomatous lesions are associated with polyhydramnios, but this finding is much rarer in sinonasal and nasopharyngeal teratomas.21–23 Elevated alpha-feto-protein (AFP) has been associated with nasopharyngeal teratomas.24 If the antenatal ultrasonography does show a substantial head and neck mass, the likelihood of perinatal airway obstruction is high and appropriate management is required.
Teratomas have been associated with other congenital deformities of the head and neck, including cleft palate, hemicrania, and anencephaly.25
There is some confusion in the older literature with regard to nasopharyngeal dermoids and nasopharyngeal teratomas. Chaudhry et al in 1978 reviewed 113 cases and reported that nasopharyngeal dermoids are frequently pedunculated and attached to the lateral nasopharyngeal wall, or onto the nasopharyngeal aspect of the soft palate, whereas true teratomas were more often larger sessile lesions.26 More recently, Coppit et al 200023 reviewed the literature and presented a case series clarifying the differences between nasopharyngeal teratomas and dermoids.
We have only one case of mature teratoma that impinged on the nasal cavity via the infratemporal and pterygopalatine fossae. This was in a young man who had previously had a teratoma of the parotid treated as a young child and then re-presented with nasal obstruction 12 years later.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
