Retrospective Study of Pediatric Sinonasal Tumors in a Tertiary Hospital Setting

Introduction

Pediatric sinonasal tumors are rare, making up approximately 4% of all head and neck neoplasms in children, and present a unique clinical and diagnostic challenge due to their nonspecific symptoms and diverse histopathology [1,2]. These tumors can originate from mucosal, cartilaginous, or osseous structures within the nasal cavity and paranasal sinuses, and they range from benign lesions, such as osteomas and angiofibromas, to aggressive malignancies, including extranodal natural killer (NK)/T-cell lymphoma and embryonal rhabdomyosarcoma.

The rarity and variable clinical presentation of these tumors often lead to delayed diagnosis. Symptoms such as nasal obstruction, epistaxis, and facial pain are frequently attributed to more common conditions, like sinusitis or allergies, resulting in late-stage presentations [3]. Imaging with computed tomography (CT) and magnetic resonance imaging (MRI) plays a vital role in delineating tumor extent and guiding biopsy and surgical planning [4]. Histopathological confirmation remains essential for accurate diagnosis and treatment selection.

Among the malignant variants, sinonasal rhabdomyosarcoma is one of the most common pediatric soft tissue sarcomas and frequently presents in parameningeal locations, making surgical resection complex, due to proximity to neurovascular structures [5]. NK/T-cell lymphoma of the sinonasal tract, although more common in adults, can present in pediatric patients, with locally invasive behavior and poor prognosis if not promptly recognized [6]. The clinical significance of these entities lies not only in their rarity but also in the need for prompt multidisciplinary management to optimize outcomes.

This case series highlights 4 pediatric sinonasal tumors treated at a tertiary care hospital, including rare presentations of rhabdomyosarcoma and NK/T-cell lymphoma. We emphasize the diagnostic nuances, advanced imaging, and therapeutic strategies, including endoscopic approaches and chemoradiation, used in these cases. By presenting unique anatomical challenges and therapeutic outcomes, we aim to contribute valuable insights to the limited literature on pediatric sinonasal oncology and to support early recognition and individualized care strategies.

Case Reports

CASE 1. SINONASAL LYMPHOMA:

An 8-year-old boy presented to our Rhinology Clinic with symptoms of bilateral nasal obstruction, blood-stained discharge, and decreased hearing of a 7-month duration. Head and neck physical examination revealed palpable multiple levels of cervical lymph nodes, at levels 2, 3, and 5. Nasal endoscopy revealed a bilateral nasal polypoidal mass congested with necrotic tissue filling the nasal cavity (Figure 1A). A CT scan was done and demonstrated a large infiltrative nasal cavity mass with skull base involvement and perineural spread of the tumor, as well as multiple enlarged cervical lymph nodes (Figure 1B). Biopsy of the nasal mass was obtained and histopathological confirmation of extra-nodal NK/T-cell lymphoma was made (Figure 1C). The patient was referred for therapeutic chemoradiation treatment.

CASE 2. SINONASAL RHABDOMYOSARCOMA:

A 7-year-old boy was referred to the Rhinology Clinic with multiple symptoms of nasal obstruction, nasal discharge, and headache. According to the boy, the symptoms were progressively worsening prior to his presentation to our hospital. The patient also developed right eye ptosis and double vision. Flexible nasal endoscopy revealed a right-sided rounded plump nasal mass (Figure 2A) involving the right sphenoid sinus and posterior ethmoids, thus obscuring the choana and nasopharynx at the right side. CT scan of the nasal cavity and paranasal sinuses revealed a lesion occupying the right side of the sphenoid and posterior ethmoids (Figure 2B), reaching up to the infratemporal region and nasopharynx, with the area of dehiscent skull base at the sphenoid sinus roof.

MRI of the paranasal sinuses revealed a huge soft tissue lesion encompassing the right side of the body of the greater wing of the sphenoid bone reaching down to the right pterygoid plates and the right parapharyngeal area (Figure 3A). The lesion dislodged the right lateral and medial pterygoid muscles, invading the right sphenoid sinus and right posterior ethmoid air cells, with scalloping of the posterior wall of the maxillary antrum and extending to the nasopharynx. The tumor partially encased the cavernous portion of the right internal carotid artery (Figure 3B). The lesion showed homogeneous enhancement after intravenous contrast administration and showed restriction on diffusion-weighted images. The tumor was also extending intracranially to the right middle cranial fossa through the foramen ovale, as shown on PET-CT (Figure 3C). The patient underwent a biopsy of the sinonasal mass under general anesthesia.

Frozen section intraoperatively showed small abnormal cells, consistent with suspected malignancy. The final histopathological report showed infiltration of soft tissue and bone by rhabdomyoblast, representing small blue cells with abnormal chromatin and slightly ample pink cytoplasm. Immunohistochemical staining revealed strong staining, with both myogenin and desmin. The mentioned findings were consistent with the diagnosis of right parameningeal embryonal rhabdomyosarcoma. The patient was referred to the Pediatric Oncology Service for chemoradiation treatments.

CASE 3. SINONASAL OSTEOMA:

A 14-year-old boy came to the clinic with symptoms of left-sided headache associated with left-sided nasal obstruction for months. There was no history of sinusitis, allergic rhinitis, or epistaxis. Flexible nasal endoscopy revealed a mass at the left nasal cavity lateral to the middle turbinate.

A CT scan of the nose and paranasal sinuses showed a left ethmoid tissue mass having inferior expansion further into the superior portion of the left maxillary antrum. It also had calcification densities just at the perimeter, as well as a heterogeneous density that resembled ground glass. The lateral aspect of the mass resulted in the renovation of the left medial orbital partition (Figure 4).

The patient underwent image-guided endoscopic endonasal removal of the mass, with preservation of the orbital bone and the base of the skull (Figure 5A, 5B). Histopathological examination confirmed the diagnosis of osteoma, showing mature lamellar bone with a compact architecture and no features suggestive of osteoblastoma or malignancy. The patient remained symptom-free at 2-year follow-up with no evidence of recurrence.

CASE 4. JUVENILE NASOPHARYNGEAL ANGIOFIBROMA:

A 15-year-old boy presented to the clinic with history of recurrent epistaxis and bilateral nasal obstruction that started with the left side for around a 2-month duration. Nasal endoscopy showed a fleshy mass occupying the nasal cavity, extending posteriorly to the post-nasal space.

A CT scan of the sinuses with contrast showed a left-sided nasal and nasopharyngeal heterogeneous avidly enhancing lesion extending to the left pterygopalatine fossa at the left side, likely representing juvenile angiofibroma (Figure 6A). Totally opacified left sphenoid and maxillary sinuses were likely due to an obstruction effect of the mass to their drainage. MRI of the sinuses showed an avidly enhancing T1-isointense and slight T2-hyperintense lesion, with its bulk in the right nasal cavity, involving the sphenopalatine foramen extending slightly laterally into the pterygopalatine fossa and posteriorly and medially to the nasopharynx. There ws minimal bulge into the left maxillary sinus and minimal extension into the posterior left ethmoid air cells. There is no definite extension into the left orbit. The mass measured 6×3.4×3.6 cm in anteroposterior, transverse, and craniocaudal dimensions, respectively, with no enlarged cervical lymph nodes. There was partial opacification of the left sphenoid sinus and mild mucosal thickening of the left (Figure 6B).

Selective carotid angiography and embolization showed the rich vascularity of the tumor (Figure 7A) and the total occlusions of the tumor vascularity after embolization (Figure 7B). The patient underwent endonasal endoscopic total excision and removal of the vascular tumor from the nose, sinuses, sphenopalatine, and pterygopalatine fossae (Figure 8A). The vascular tumor was sent completely to the histopathological examinations which confirmed the diagnosis of vascular juvenile nasopharyngeal angiofibroma (Figure 8B). The patient was on regular clinical and endoscopic follow-up, with no signs of recurrence after 5 years (Figure 9).

Discussion

Head and neck tumors are seldom encountered in the pediatric population. They represent around 4% of all tumors. It is critical to recognize such tumors, since the management strategy and prognosis will differ based on the diagnosis. Pediatric sinonasal tumors show different characteristics than do adult sinonasal tumors in regard to clinical presentation and prognosis, and the nasal tumors include benign and malignant tumors, with benign tumors being more common. The most commonly encountered benign lesions are listed in the literature as congenital masses, such as glioma, encephalocele, polyps, hamartoma, and hemangioma. On the other hand, rhabdomyosarcoma and lymphoma are the most frequently encountered malignant lesions. In our series, we reported benign and malignant cases encountered in our center, to enhance understanding of the approach to pediatric sinonasal masses [1]. Most cases are reported to be diagnosed at a late stage of the disease, which is attributed to the subtle or asymptomatic course of sinonasal tumors. Benign tumors might show almost no symptoms, and, in contrast, malignant tumors are more likely to cause nonspecific symptoms, such as rhinorrhea, nasal obstruction, epistaxis, headache, and vision changes [1].

Our reported cases are consistent with those in the literature, and all patients presented to our clinic after their symptoms progressed over months, which indicates that it is difficult to diagnose these tumors early. The subtle course of these tumors warrants an extensive review of the patient. Then, once the suspicion is raised, immediate action can be taken, and a complete assessment including history and physical examination, with nasal endoscopy focusing on neurological and ophthalmic assessment, laboratory tests, and imaging with CT and MRI can be performed. Biopsies and histopathology are required to attain the correct diagnosis [3].

Sinonasal osteomas are slow-growing, benign tumors of the bone that are most commonly seen in the frontal sinus, followed by the maxillary and ethmoid sinuses. They tend to be asymptomatic and discovered incidentally during imaging. Previous studies found that osteomas are commonly confused with osteoblastoma [7]. However, osteoblastoma rarely occurs in the head and neck or paranasal sinuses. Osteomas commonly present as headache, as in our reported case, or could present as an external deformity, nasal obstruction, and facial pain, similar to the symptoms reported in the literature. Its slowly growing property leads to chronic symptoms that are often misdiagnosed [8].

The surgical option should be considered when the osteoma obstructs sinus outflow, exhibits evidence of growth into nearby vital structures, like the orbit or skull base, or produces chronic symptoms, including headache, face discomfort, or nasal blockage. Nonetheless, a conservative approach with periodic imaging surveillance has been found appropriate and safe in asymptomatic patients with no signs of aggressive growth or structural damage [7,8]. CT and MRI are of particular importance for assessing the size, anatomical relations, and surgical planning of these tumors [7]. Surgical resection could be done through different approaches depending on the location and extent of the tumor [9]. As in our case, CT was used for reaching the diagnosis, and the tumor was surgically resected by endoscopic image-guided surgical excision, which yielded a good outcome.

Juvenile nasopharyngeal angiofibromas are rare but locally aggressive benign tumors that are highly vascular. They make up approximately 0.5% of head and neck tumors and primarily affects adolescent males. Their origin is still not fully understood; however, the male predominance can be explained by the high androgen receptor expression. Juvenile nasopharyngeal angiofibroma can be classified based on clinical features and imaging into 3 types. Type 1 is localized to the nasal cavity, sinuses, nasopharynx, or pterygopalatine fossa; type 2 invades the infratemporal fossa, buccal space, orbit with anterior or middle cranial fossa invasion, with intact dura mater; and type 3 is a massive tumor in the middle cranial fossa. The clinical presentation of juvenile nasopharyngeal angiofibroma commonly includes epistaxis and unilateral nasal obstruction, which is consistent with our case. As with most head and neck tumors, a thorough clinical assessment, nasal endoscopy, and imaging are the modalities of diagnosis that demonstrate the details of the location, extent, size, and anatomical relation of the tumor [6]. The literature shows that early detection and proper management is crucial for a good outcome, and the treatment choice is surgical excision with pre-operative angioembolization. Correspondingly, in our case, we attained similar management. The recurrence rate of juvenile nasopharyngeal angiofibroma depends on the extent of the disease, and proper surveillance with nasal endoscopy and MRI is warranted [3].

In the pediatric age group, the most common encountered malignant tumor of head and neck is non-Hodgkin lymphoma, accounting for 25%. Furthermore, sinuses are considered the second most common primary location of non-Hodgkin lymphoma after neck lymph nodes. The most common variant of non-Hodgkin lymphoma is diffuse large B-cell lymphoma, which invades the sinuses in 90% of cases, while it primarily arises from the sinuses in only 10% of cases [9]. A rare variant is NK/T-cell lymphoma, such as in our case, and it primarily present as nasal-type extra-nodal lymphoma [10]. In addition, it usually occurs in adults and rarely involves children and adolescents. In most cases, patients present with localized nasal/sinus presentation in the form of nasal obstruction, nasal discharge, and facial swelling [6]. Similarly, our patient presented with bilateral nasal obstruction, blood-stained discharge, and decreased hearing. The disease is more prevalent in male patients, and patients usually have associated B symptoms and elevated lactate dehydrogenase levels. Diagnosis is established via histopathological tissue confirmation, which will reveal necrosis and angioinvasion [10]. Radiotherapy as a treatment for NK/T-cell lymphoma in children and adolescents at early stages is associated with good outcomes; hence, early histopathological diagnosis is beneficial for the patient [11].

Rhabdomyosarcoma is a rare tumor accounting for 3% of overall pediatric tumors. It is however considered one of the most common soft tissue sarcomas among pediatric patients, accounting for 50% [12]. The embryonal type of rhabdomyosarcoma is the most common type, representing 60% of overall cases, presenting with head and neck involvement, and occurring more often in children and adolescents [13]. Soft tissue sarcomas and lymphomas account for over 50% of head and neck malignant tumors in pediatric patients. Sites usually involved in rhabdomyosarcoma of the head and neck include the orbit, parameningeal sites (nasopharynx, nasal cavity, paranasal sinuses, temporal bone, pterygopalatine fossa, and infratemporal fossa), and, finally, non-parameningeal sites. Patients usually present with nasal obstruction, nasal discharge, and otitis media. Patients might also present with proptosis of the eye if the orbit is involved [14].

In our case, the patient presented with nasal obstruction, rhinorrhea, and headache, as well as right eye ptosis. Diagnostic workup in case of suspicion of rhabdomyosarcoma includes imaging using CT and MRI scan of the tumor, to demonstrate the extent of tumor and relation to vital structures. This is followed by CT of chest, abdomen, and pelvis for staging of disease. Confirmatory diagnosis is made by biopsy of the lesion endoscopically, or intraoperatively in uncooperative patients [13–15]. Sinonasal rhabdomyosarcoma is often treated with surgical excision when the tumor is confined and can be safely excised without endangering important neurovascular structures. However, because of the high risk of morbidity, surgical excision may not be recommended when the tumor affects anatomically sensitive sites, such as the internal carotid artery, or penetrates into the cavernous sinus and middle cranial fossa. In these situations, the first line of treatment is usually chemotherapy and radiation therapy, which have been associated with favorable survival results and are regarded as first-line treatments in situations with poor resectability or high-risk anatomical involvement. Surgery is reserved for residual or recurring lesions following chemoradiation, when the tumor becomes more localized or operable [12,14,15].

Conclusions

Pediatric sinonasal tumors, although rare, and complex entities that require early recognition and a multidisciplinary treatment approach. This case series highlights the diverse clinical presentations, diagnostic challenges, such as late presentation and nonspecific symptoms, and treatment modalities for benign and malignant sinonasal tumors in children. Minimally invasive endoscopic surgical techniques proved effective in managing benign tumors, like osteoma and juvenile nasopharyngeal angiofibroma, offering favorable long-term outcomes. In contrast, malignant tumors such as NK/T-cell lymphoma and embryonal rhabdomyosarcoma required aggressive multimodal therapy, which highlights the importance of timely referral to oncology specialists. The findings emphasize the importance of advanced imaging, histopathological confirmation, and individualized treatment strategies to optimize patient outcomes. Future research is essential to refine diagnostic and therapeutic approaches, ultimately improving prognosis and quality of life for pediatric patients with sinonasal tumors.

This case series was conducted in Department of Otolaryngology-Head and Neck Surgery of King Fahad Specialist Hospital.