Extensive epithelioid hemangioendothelioma of the maxillary sinus: A case report

Highlights • Epithelioid haemangioendothelioma is a rare vascular tumor which can originate from the maxillary sinus.• Surgical excision is the treatment of choice for local tumors.• Exclusive radiation therapy with chemotherapy can be an option for extensive forms.


Introduction
Epithelioid hemangioendothelioma (EHE) is an uncommon vascular tumor of soft tissue, which was first reported by Weiss and Enzinger in 1982. This unusual vascular neoplasm is characterized by proliferation of a distinct type of endothelial cells which show epithelioid morphology.
This rare tumor with an estimated incidence of approximately one person in every 1.000.000 have histological and clinical features intermediate between those of benign hemangioma and conventional angiosarcoma.
Due to the rarity and histological similarity to other tumors, diagnosis can be challenging [1].
There are very few cases of EHE of nasal cavity described in the English literature [2]. We describe here an advanced case of EHE of maxillary sinus in a young man who was treated by radiation therapy and chemotherapy. This work is reported in line with SCARE criteria [3]. * Corresponding author.

Case report
A 18-year-old man presented with a 3 months history of right intermittent epistaxis, permanent nasal obstruction, anosmia and right hearing loss. No other nasal or ocular symptoms were noticed. The physical exam found a right exophtalmia, a swelling deformatted right hemiface (Fig. 1) and a bulky whitish tumor filling the right nasal cavity at the nasal endsocopy. Cranial nerves, neck and oral cavity exams were normal.
A computed tomography showed heterogeneous tissue tumor, measuring 8.7 × 6.5 cm heterogenously enhancing. Important lysis of the inner wall of the right orbit with important extension (intraorbital, intra sellar, nasopharynx and right pterygoide fossa) (Fig. 2).
Magnetic resonance imaging (MRI) confirmed the orbital, intra sellar and the right pterygoide fossa extension with a hyper vascularized nasopharyngeal process filling the right nasal cavity (Fig. 2).
Microscopic examination of the biopsy showed ulcerated tumor proliferation richly vascularized with thickened-wall vessels and turgid endothelium. This proliferation is made of globular cells with abundant eosinophilic cytoplasm. The nuclei are moderately hyperchromatic sites of moderate cytonuclear atypia. This proliferation is dissociated by lymphoplasmocytes and histiocytes. Immunohistochemical study shows cytokeratin negativity and positivity of CD31. The histological aspect is compatible with a epitheloid hemangioendothelioma (Fig. 3).  Due to aggressivity, advanced tumor stage and intracranial extension, the surgery was contraindicated.
The patient received 55 Gy of intensity modulated radiotherapy (IMRT) with weekly chemotherapy made of cisplastine (40 mg/m 2 ) for 6 weeks.
Otherwise the patient presented a mucositis of the right cheek, cured by medical treatment.

Discussion
EHE was first described by Weiss and Enzinger in 1982 as a tumor that affects soft tissue [1]. It is an angiocentric vascular tumor with endothelial component. There is no sex predilection and age of onset is variable [4].
The nasal cavity is also an extremely rare location for this tumor, with only 7 cases reported in the literature since 2016 [6]. Even rarer, however, is an EHE primarily originating within a paranasal sinus. To our best knowledge, only two cases of EHE originating in the maxillary sinus has been previously described in the literature [7,8].
Both by clinical as by histological characteristics, EHE is considered as a tumor of intermediate malignancy because of both local recurrences and metastatic potential [6].
The tumor cells often develop as a painful mass in either superficial or deep soft tissue. On gross inspection, the tumor usually has a variegated, white red color that offers a hint of its vascular nature [3].
Histologically, the tumor is composed of short strands or solid nests of rounded to slightly spindled endothelial cells. Some canalized vascular channels and clusters of erythrocytes are seen.   Immunohistochemically, these tumors are positive for cytokeratin (especially CK18), and vascular markers including CD31. These tumors have an intermediate and variable malignancy pattern in terms of both local recurrences and metastatic potential [8].
Therefore, wide local excision is considered the treatment of choice, and is probably curative in most cases. In a few cases, adjuvant treatment with radiotherapy or chemotherapy has been given [3].
In our case, it was local aggressive EHE of the maxillary sinus in a young man with intracranial extension, treated with IMRT with weekly chemotherapy. To our best knowledge, this is the first EHE treated only with radiation therapy and chemotherapy.
Given the limited clinical data, evidence based treatment protocols for treatment for sinonasal EHE are not possible. Therefore it requires a close clinical follow-up because of its potential to recur and metastasize [8].
After 18 months follow-up, the evolution was good with regression of the exophthalmos and 50% of the tumor size.

Conclusion
EHE is an uncommon tumor of soft tissue whose nasal cavity is extremely rare but should be considered in the differential diagnosis of a nasal cavity mass. Surgical excision is the treatment of choice when limited to the nasal cavity. Radiation therapy with chemotherapy can be an option for EHE particularely when it is extensive.

Conflicts of interest
The authors declare that they have no competing interests.

Sources of funding
This research did not receive any specific grant(s) from funding agencies in the public, commercial, or not-for-profit sectors.

Ethical approval
I certify that this kind of manuscript does not require ethical approval by the Ethical Committee of our institution.

Consent
Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.