Desmoid Fibromatosis of Maxillary Sinus Masquerading as Nasal Polyp: A Case Report

Abstract

Desmoid fibromatosis is also known as aggressive fibromatosis. It is a neoplastic monoclonal proliferation of fibroblasts, with an incidence of 2 to 4 per million per year. Its incidence peaks at 8 years of age and in the third/fourth decades of life. Here we discussed a patient in third decade of life who presented with unilateral nasal blockage with a picture suggestive of sinonasal polyposis on examination. On histopathology, he was diagnosed with Desmoid fibromatosis. Though a rare entity, Desmoid fibromatosis should be kept in mind as a differential diagnosis for appropriate patient management. As per our knowledge, in India this is the first documented case of desmoid fibromatosis arising from maxillary sinus.

Introduction

Desmoid fibromatosis is a rare benign connective tissue process originating from the mesenchymal stem cells and shows locally aggressive behaviour [1].

It is very rare, accounting for less than 3% of all soft tissue tumours [2].

Although it does not metastatize but it has the tendency to recur and be locally destructive. It has now been classified as “intermediate, locally aggressive” tumor in the World Health Organization classification of soft tissue tumors.

They are characterised by local invasion and associated with high rate of local recurrence. The most common sites of the lesion are mesentery, retroperitoneal space, abdominal wall or extra-abdominal sites such as the trunk and extremities. 7–15% of all desmoid tumors are seen in the head and neck region, 57% of which occur in the pediatric population [3].

In the head & neck region, mandible is the most commonly affected location, followed by the submandibular area, neck, tongue, and paranasal sinuses, respectively [4, 5].

In this report, we describe a rare case of desmoid fibromatosis of maxillary sinus masquerading as nasal polyp of an adult man.

Case Presentation

A 33-year-old male came to the Otolaryngology outpatient department with complaints of right-side nasal blockage for 3 months. On examination of nasal cavity, there was a presence of polypoidal growth in right nasal cavity. The polyp was pearly white in colour with smooth appearance. A diagnostic nasal endoscopy was performed. On diagnostic nasal endoscopy, the polyp was completely occupying the right nasal cavity. On probing, it was firm in consistency and bleeds on touch and was confirmed to arise from the right middle meatus (Figs. 1, 2, 3). Ear and Throat examination was normal. The patient had a past history of stroke and he was on tablet aspirin 75 mg/day. An initial course of oral antibiotics, oral steroid and intra nasal corticosteroids were given to the patient.

Fig. 1.

Polyp completely occupying the right nasal cavity

Fig. 2.

Polyp arising from right middle meatus

Fig. 3.

On probing, the polyp was firm in consistency and bleeds on touch

There was no symptomatic relief following the treatment and the patient was planned for functional endoscopic sinus surgery under General Anaesthesia.

CT scan of the nose and paranasal sinuses was suggestive of large right antrochoanal polyp measuring approximately 31 × 41 mm causing significant right nasal cavity obstruction and widening of the right osteomeatal complex. Thinning of walls of right maxillary sinus. No obvious bony destruction (Figs. 4, 5).

Fig. 4.

Non contrastCT of nose and paranasal sinuses demonstratesrelatively homogenous mass in right nasal cavity with complete opacification of right maxillary sinus. No associated bony destruction. No calcification

Fig. 5.

On contrast enhanced CT scan of paranasal sinuses demonstrates minimal enhancement of the mass with widening of the right osteomeatal complex

After proper written informed consent, Functional Endoscopic Sinus surgery was planned. During the surgery it was observed that the lesion was completely adherent to the right inferior turbinate, the right middle turbinate and the nasal septum and the walls of the maxillary sinus. Meticulous dissection of the polyp from the sinus was performed and then it was removed in toto and sent for histopathological examination.

Histopathological report stated it to be a moderately cellular mesenchymal tumour comprising of spindle shaped cells having elongated, wavy nuclei, indistinct nucleoli and eosinophilic cytoplasm with occasional mitoses and focal nuclear palisading, suggestive of Low-grade spindle cell neoplasm.

On Immunohistochemistry, IHC markers, SMA, Caldesmon H, CD34, B Catenin were positive. Ki-67 was 10% and STAT 6 was negative.

The above markers were suggestive of Desmoid type fibromatosis of the right maxillary sinus.

Follow-up of the patient was done for 3 months post-operatively and no recurrence was seen (Fig. 6).

Fig. 6.

One month post operation endoscopy demonstrates complete disease clearance and no recurrence

Discussion

Desmoid tumour is a rare benign, locally aggressive soft-tissue tumour accounting for approximately 0.03% of all neoplasm and less than 3% of all soft tissue tumours [2].

There is no known aetiology of desmoid tumours, but trauma, endocrine or genetic factors have been speculated as the possible etiologic factor. These tumours can occur at any age but has been observed more commonly between the third and fourth decade of life. The age of the patient in the above case report coincides with the literature. It is more common in females with overall female-to-male ratio between 3:2.

Incidence

Because of the rarity of the tumor in head & neck region, a retrospective study was done by Gnepp et al. from 1885 to 1985 and 25 such cases were found. The maxillary antrum was most frequently involved in 90% of the cases, the nasal cavity and ethmoids were involved in 20%, while the orbits, sphenoid and frontal sinuses were only rarely involved [6].

In a case report by kawamata et al., they excised a maxillary sinus desmoid tumor which had extended to the ethmoid and sphenoid sinuses, to its maximum possible extent [7].

In a case report by Makoto et al., a solid mass occupied the left maxillary sinus and was firmly attached to its walls so that it was impossible to remove it. biopsy diagnosed it as a desmoid tumor [8].

All the above cases were reported out of India.

In India in a case report by Raj et al., a patient presented with right sided nasal obstruction and swelling over the right maxillary region but on CT Scan, it was cleared that the mass did not involve the maxillary antrum and nasopharynx. It was stated that a heterogeneous mass was seen occupying the fight nasal cavity. The soft tissues overlying the mass were involved [9].

By means of this manuscript, we present a rare case of desmoid fibromatosis arising from the maxillary sinus and occupying the nasal cavity. No such case has been documented in India as per our knowledge.

Presenting Symptoms

Due to its rarity, desmoid tumours of the maxillary sinus may present with variety of symptoms such as nasal blockage, epistaxis and facial pain, proptosis, facial swelling, anosmia and rhinnorea.

According to Sharma et al. in their study, it was stated that the most common presenting symptom of head and neck fibromatosis is an enlarging painless mass [10].

In our case, the patient presented with complaints of unilateral nasal blockage.

Investigations and Diagnosis

Radiology

CT and MRI are imaging modalities of choice and are valuable in assessing extent of disease and involvement of vital structures. Imaging findings are variable based on cellularity and collagen content of lesions [11, 12].

In a study by Choi et al., it was stated that a in case of desmoid-type fibromatosis, computed tomography (CT) demonstrated an expansile mass filling both nasal cavities, with bony erosion of the anterior skull base, right sphenoid sinus, right orbital apex, and hard palate. Immunohistochemistry diagnosed it with desmoid-type fibromatosis [13].

In a study by Shuaibu et al., in a 29 year old female with Desmoid fibromatosis, computed tomographic (CT) scan of the paranasal sinuses showed an expansile homogenous huge soft-tissue mass arising from the left maxillary antrum and extending to the left orbit causing proptosis and distortion of the ipsilateral nasal cavity. Absence of an intranasal mass prompted a sublabial approach for an incisional biopsy and histology revealed features of desmoid tumor [14].

Histopathology

Histopathologically, the tumor process consists of elongated, slender, spindle-shaped cells of uniform appearance, surrounded and separated from one another by abundant collagen, with little or no cell-to-cell contact. The cells lack hyperchromasia or atypia, and cellularity varies within the lesion. The constituent nuclei are small, pale staining, and sharply defined, with 1–2 min nucleoli [14].

Histologically, lesions comprise uniform-appearing spindle cells with intervening collagenous stroma and without dysplastic features [11, 12].

As per Sarah et al., definitive diagnosis often requires incisional biopsies, as fine needle aspirations and core biopsies are frequently inconclusive [4].

In a study by Shuaibu et al. and Makoto et al., biopsy and histopathologic report was able to reveal and diagnose desmoid tumor [8, 15].

Immunohistochemistry

In a study by Choi et al., immunohistochemistry diagnosed it with desmoid-type fibromatosis [13].

According to Buitendijk et al., immunohistochemical analysis showed positive staining with vimentin in 100% of AF patients, with SMA in 78% of patients, with actin in 30% of patients, with S-100 protein in 8% of patients, and with desmin in 0% of patients [16].

Similarly, our patient’s diagnosis was turned in the direction of Desmoid fibromatosis with the help of histopathology and immunohistochemistry aided in the definitive diagnosis.

Management

In a study by Raj et al., it was suggested that surgical management is to be considered the first line and if proven inadequate, then patients are to be subjected to radiotherapy [9].

As per Hoos et al., the standard treatment for AF is wide surgical resection because AF grows relatively quickly, is invasive to surrounding tissues, has unclear borders, and a high frequency (20–70%) of local recurrence [17].

Similarly, our patient underwent functional endoscopic sinus surgery and biopsy sample was sent for histpathology and immunohistochemistry.

Conclusion

Maxillary sinus is a rare site of occurrence of Desmoid fibromatosis. It is large, bulky tumor with a tendency to infiltrate locally into adjacent structures. Computerized tomography is the radiological investigation of choice. It reveals the site and extent of the lesion and acts as a landmark for surgery. Biopsy is necessary to establish the diagnosis. The histological characteristics of the tumour is the presence of spindle cells, collagenous stroma and infrequent mitosis. Immunohistochemistry is ideal for definite diagnosis.