Spindle cell carcinomas are considered to be highly aggressive, biphasic malignant tumor that occurs rarely in head and neck region [1] . Histologically, these tumors consist of malignant epithelial and malignant mesenchyma components [2] . The epithelial component is a squamous cell carcinoma admixed with a malignant sarcomatous component that is either non-descript or contains heterologous elements (i.e. osteo or chondrosarcomatous) [1] . In the past, these tumors have been given variety of names including sarcomatoid carcinoma, carcinosarcoma, pseudosarcoma, collision tumor, and pleomorphic carcinoma [3] .

Spindle cell carcinoma is considered to be a poorly differentiated squamous cell carcinoma, with elongated epithelial cells that resemble sarcoma [2] . Thus regardless of having a mesenchymal appearance, it has an epithelial origin and derived from squamous cells which can be confirmed by use of electron microscopy and immune-histochemical stains for keratins [4] [5] . Despite its rarity in the head and neck region, the most frequently involved site is the larynx, with reports of cases found in nasal cavity, hypopharynx, oral cavity, esophagus, trachea, maxilla and skin also present in the literature [6] . Spindle cell carcinoma arising in maxilla is much rarer occurrence in literature [7] with few cases reported since 1957 (Table 1).

We report here a case of Spindle cell carcinoma arising from the maxilla in a patient who was treated at our institute.

A 34-years-old female, presented in ENT clinic with complaints of left nasal blockage which progressed over 4 months associated with diffuse swelling, pain and hypoesthesia of left cheek. There was left Eye proptosis and decrease vision for 6 months accompanied with loss of left upper molar and premolar tooth. Patient’s past surgical or medical history was not significant for any pathology and no history of addiction to tobacco or other drugs was identified. On examination, there was a non-tender left sided facial swelling which was firm to touch and non-indurated. On anterior Rhinoscopy Nasal cavity failed to show any mass/lesion in the left side while rigid nasopharyngeal scope was also normal. There was loss of left upper molar teeth on left side with granulation tissue which bled on manipulation. The left eye had obvious proptosis with no light perception and no ocular movements while there was no light or pupillary reflex as well. Rest of ENT and neck examination was unremarkable. Patient was advised Routine labs and C.T head and neck, chest with contrast. After obtaining a computed tomographic image, biopsy was taken from left upper maxillary granulation tissue. Figure 1 C.T scan showed the lesion to be destructive in nature, occupying the whole left maxilla but surprisingly sparing left nasal cavity. Superiorly tumor extended and eroded the orbital floor in antero-posterior fashion making its way in to orbital cavity proper and apex, while laterally extending to temporal and infra-temporal fossa, with posterior extension into pterygoid plates. The histology confirmed the presence of atypical cells with mitotic figures. The tissue was further reviewed under immuno-histochemical stains and the diagnosis of spindle cell carcinoma was confirmed. Figure 2 & Figure 3 patient underwent metastatic work-up which was negative and no other systemic diseases were identified.

After counseling, detail discussion and consent; patient underwent left subtotal maxillectomy with orbital exentration while the pterygoid muscle and plates were found to be devoid of disease and temporal fossa extension of tumour was cleared via tunnel created through lateral wall of orbit. Surgery was followed by 2 cycles of cisplatin (30 mg/m²) of chemotherapy and intensity-modulated radiation therapy (IMRT) over the left maxilla for a total of 70 Gy in 35 fractions. Patient remained free of any local or regional recurrence since as

reviewed on regular follow up visits and C.T scan at one year post surgery Figure 4.

Sarcomatoid carcinoma is a rare biphasic malignant tumor, and is reported to account for less than 1% of all tumors within the oral cavity [8] . Its development is considered to be multi-factorial with poor oral hygiene, alcohol or tobacco intake and previous radiation considered as risk factors. Genetic predisposition has also been reported in some studies [4] . With a male predominance, it generally occurs in the sixth decade of life, with cases in younger ages reported as well Table 1.

Bulk of the tumor is made up of spindle cells with remaining part consisting of the epithelial cells [8] [9] . Various theories have been put forward to explain the histological appearance of spindle cell carcinoma Some researchers believe that both these components arise from separate stem cells, the so called collision tumor. While others favor the concept of spindle cells being atypical reactive proliferation of the stroma, despite all arguments, the most widely accepted theory supports the monoclonal hypothesis that states that they arise from the same stem cells and have actually undergone “dedifferentiation” [9] [10] . Some considered the development of spindle cells being derived from the epithelial cells themselves with functional loss of genes responsible for epithelial differentiation [9] .

There are several differential diagnoses for spindle cell carcinoma and these include leiomyosarcoma, rhabdomyosarcoma, myloepithelial carcinoma and malignant peripheral nerve sheath tumor. For diagnosis of spindle cell carcinomas, light microscopy gives initial important clue, and immuno-histochemical stains further help in the confirmation of the diagnosis. Epithelial differentiation and staining for one or more epithelial markers supports the diagnosis. In most cases (26% - 62%) Keratin and cytokeratin are commonly found to be positive. Furthermore, positivity to mesenchymal-type markers is also demonstrated. Almost 100% of the cases show positivity for vimentin and about a third of them for smooth muscle actin [11] .

In literature the treatment of spindle cell sarcoma follows same footsteps as that of squamous cell carcinoma of similar stage with wide surgical excision being the preferred choice of treatment [Table 1]. Nevertheless, in comparison to squamous cell carcinoma, within the head and neck region, spindle cell carcinoma is considered as a more aggressive tumor and has a propensity to recur and metastasize early [12] . For tumors of the oral cavity as well as the larynx, surgery is the mainstay of treatment. In comparison to radiation therapy alone, the prognosis is better for surgery [13] [14] . Chemotherapy has proven to have good results as part of neo-adjuvant and adjuvant treatment in helping to reduce the tumor size. However, when used as a sole treatment modality, it has ambiguous results [15] . Treatment also depends on various other factors; like low grade tumor, small tumor size, absence of previous radiation therapy and polypoidal growth indicate good prognosis [14] , while factors that influence choice of treatment clearly depends primarily upon the extent of lesion and surgeon being able to excise the lesion completely. This is followed by Radiation and +/− chemotherapy [15] . But no clear guideline is available in literature to support one treatment modality over the other. Sarcomatoid carcinoma is considered as a more aggressive tumor, with a tendency to recur and metastasize early when compared to squamous cell carcinoma within the head and neck region [11] [12] .

The presence of distant metastasis and the depth of invasion of the tumor are considered to be reliable prognostic features for the disease [16] . Regional and distant metastasis does greatly alter the prognosis as well as the overall mortality rate. Cervical lymph node involvement is present in approximately 7.5% - 26% of the cases and an even lesser distant metastasis [17] . The most frequent site of distant metastasis is the lungs. Lambert et al in his study, reported the incidence of lung metastasis to be about 5% with the overall mortality rate reported in literature to be 14% - 32% [17] [18] .

In conclusion, spindle cell carcinoma of maxilla is a rare entity in head and neck. It is a potentially aggressive tumor with high recurrence rate. Due to the fact that it has both epithelial and mesenchymal tissue, it poses a diagnostic challenge for the histopathologist. Immune markers and special stains have an important role to play in its differentiation with other tumors.

Junaid, M., Kazi, M. and Qadeer, S. (2017) Spindle Cell Carcinoma of the Maxilla: A Case Report of Rare Entity. Surgical Science, 8, 220-227. https://doi.org/10.4236/ss.2017.85025