Nasal angiomyolipoma causing persistent nasal congestion

Abstract

Angiomyolipomas are benign tumors composed of blood vessels, adipose tissue, and smooth muscle. Usually, these lesions are located in the kidney and are found in association with tuberous sclerosis. The current case describes the rare presence of an angiomyolipoma within the nasal vestibule, leading to nasal obstruction. Surgical resection of the lesion was curative, and the patient’s nasal congestion improved postoperatively. Consistent with previous findings in the literature, the patient’s angiomyolipoma had not recurred at subsequent postoperative visits.

Angiomyolipomas are benign tumors generally composed of fat, smooth muscle, and blood vessels. These tumors are usually reported in association with a diagnosis of tuberous sclerosis and are often found in the kidney. ¹ However, there are case reports of angiomyolipomas arising in other areas of the body, such as the adrenal gland or liver. ^{2 , 3} The current case describes the presentation of an angiomyolipoma arising in the nasal vestibule, causing obstructive symptoms. An angiomyolipoma in this location is exceedingly rare, but the results of this case suggest that it can be managed well with resection.

CASE DESCRIPTION

A 65-year-old man presented to the otolaryngology clinic with a progressively enlarging left-sided nasal vestibular mass for 2 years. He had noticed persistent difficulty breathing through the left side of his nose and described increased snoring over the past several months. The mass did not bleed or change rapidly in size. In-office endoscopic evaluation of the right side of the patient’s nose noted a normal appearance with no pus or polyps. Computed tomography (CT) of the sinus with contrast demonstrated a 1.6 × 1.7 cm soft tissue mass arising from the left lateral nasal vestibule with hypervascularity (Figure 1). The remainder of the sinuses and nasal cavities appeared normal.

Figure 1.

CT of the sinus with contrast, (a) axial and (b) coronal images, demonstrating an enhancing mass in the left lateral nasal vestibule.

The patient underwent definitive resection with an excisional biopsy. Intraoperatively, a soft tissue mass was noted arising from the lateral wall of the left nasal vestibule slightly posterior to the mucosquamous junction, extending to but not including the head of the inferior turbinate. The lesion appeared to arise solely from the mucosa without direct involvement of the skin of the nasal vestibule. The remainder of the nasal cavity was unremarkable. Pathologic findings were consistent with a 1.2 × 1.1 × 0.8 cm pink-tan, solid polypoid mass that was attached to a 1.2 × 1.0 × 0.2 cm ellipse of tan-pink mucosa on gross examination. Microscopically, the polypoid mass was attached to the squamous mucosa but showed no surface epithelial lining. It contained adipose tissue (approximately 30%) with no atypia, mature-appearing spindled smooth muscle cells, and thick-walled blood vessels. Immunohistochemically, smooth muscle cells were diffusely positive for smooth muscle actin and negative for HMB-45. These features are diagnostic of angiomyolipoma (Figure 2). The patient tolerated the procedure well. He did not report any bleeding or significant pain and described a dramatic improvement in his breathing.

Figure 2.

Angiomyolipoma at (a) low power, showing a polypoid mass (hematoxylin-eosin stain, original magnification ×20) and (b) higher power, where the three components are disorganized and include adipose tissue, smooth muscle, and thick-walled blood vessels (hematoxylin-eosin stain, original magnification ×100).

DISCUSSION

Angiomyolipomas are a fairly rare lesion considered part of the family of tumors with perivascular epithelioid cell differentiation (PEComas). ^{4 , 5} They are often associated with tuberous sclerosis, a neurocutaneous syndrome usually diagnosed in infancy and associated with skin lesions, seizures, and development of hamartomas throughout the body. ⁶ The patient in the current case did not have a diagnosis of tuberous sclerosis or have any of the features expected in association with the disease. This finding is consistent with previous reports of nasal angiomyolipomas, further supporting the notion that angiomyolipomas of the nasal cavity arise without an association with tuberous sclerosis. ¹

Nasal angiomyolipomas have been described <30 times in the literature and therefore can be mistaken for other lesions. ⁷ The enhancement of angiomyolipomas in CT scans with contrast can cause them to be mistaken for vascular tumors. ⁸ However, when evaluating these lesions on CT scans, they are not usually found to invade surrounding structures, which is consistent with a benign pathology. ⁹ The differential diagnosis of masses in the nose is vast and includes relatively common findings such as polyps, papillomas, or hemangiomas and more uncommon lesions such as angiofibromas, encephaloceles, or esthesioneuroblastomas. ¹⁰ Surgical resection appears curative, with no reports of recurrence in the literature. ^{1 , 7} The final diagnosis can be made upon pathologic analysis.

The results of the case suggest that while rare, nasal angiomyolipomas should also be considered as a possible diagnosis in a patient with a unilateral mass with obstructive symptoms. The patient described had a nasal angiomyolipoma that caused nasal obstruction which resolved following resection.