Angiolipoma of the nasal alar base: A case report

Abstract

BACKGROUND

Angiolipoma is a rare benign tumor composed of mature adipocytes and proliferative capillary networks, most frequently found in the extremities. Occurrence in the nasal region, particularly at the alar base, is exceedingly rare, with no prior cases documented in the English-language literature.

CASE SUMMARY

A 59-year-old Korean lady presented with painless, progressive swelling of the right nostril of the right nasal alar base. Radiologic evaluation revealed a well-circumscribed, enhancing 10 mm mass without bony erosion or intranasal extension. The lesion was successfully excised via a local alar sulcus approach under local anesthesia. Histopathological examination revealed a well-encapsulated lesion composed of mature adipose tissue interspersed with variably sized blood vessels. Immunohistochemical staining confirmed vascular smooth muscle positivity for α-smooth muscle actin within the vascular walls, consistent with the diagnosis of angiolipoma. No atypia, mitosis, or infiltration was identified. The surgical course was uneventful, with cosmetic and functional results, with no evidence of recurrence at follow-up.

CONCLUSION

This is the first published case to widen the morphological spectrum of nasal angiolipomas and underscores the relevance of including angiolipoma in the differential diagnosis of vascular-appearing nasal tumors. Complete surgical excision provides good cosmetic and functional benefits with a low chance of recurrence.

Key Words: Angiolipoma; Nasal alar base; Vascular tumor; Lipoma variant; Head and neck neoplasm; Case report

Core Tip: This is the first published case to widen the morphological spectrum of nasal angiolipomas, particularly at the nasal alar base and underscores the relevance of including angiolipoma in the differential diagnosis of vascular-appearing nasal tumors. Complete surgical excision provides good cosmetic and functional benefits with a low chance of recurrence. It also provides an overview of the surgical technique for reconstruction of alar base defects. This case adds valuable insight to the literature and encourages heightened clinical suspicion for accurate diagnosis and optimal surgical management.

INTRODUCTION

Angiolipoma is a benign mesenchymal tumor considered a vascular variant of a lipoma. It is composed of mature adipocytes scattered among a noticeable capillary-type vascular network, which often contains fibrin microthrombi[1]. Due to its vascularity, it usually develops in the trunk or extremities, where it frequently manifests as a sore subcutaneous nodule. Angiolipomas arising in the head and neck region are rare, and those affecting the nasal area are particularly unusual[2]. Only a few of the nasal instances have been published in the literature, including one described in the nasal dorsum[3] and another presenting as a nasal tip deformity[4].

Nasal angiolipomas remain extremely uncommon, with the majority occurring on the nasal dorsum and tip, according to a thorough analysis of previously published cases[5]. To the best of our knowledge, this is the first recorded instance of an angiolipoma developing exclusively from the nasal alar base, a place not previously reported in the available English-language literature. This report describes the clinical features, radiologic findings, operative details, and histopathologic characteristics of the patient, and highlights important diagnostic points clinicians should consider when evaluating vascular-appearing lesions in the nasal region.

CASE PRESENTATION

Chief complaints

A 59-year-old Korean female patient presented to a local otolaryngology clinic with persistent swelling of the right nasal base and a palpable mass in the alar region.

History of present illness

She reported having undergone rhinoplasty ten years earlier, 2 years back, she gradually noticed a small lump that slowly increased in size. Despite the cosmetic concern, she denied pain, obstruction, bleeding, or any other nasal symptoms. After that, she was referred to our tertiary hospital for further management.

History of past illness

Her medical and surgical and histories were unremarkable.

Personal and family history

Her family history was otherwise unremarkable, and there was no history of trauma.

Physical examination

On physical examination, a well-circumscribed, slightly compressible nodule measuring approximately 1 cm was detected at the right alar base. The overlying skin was intact and showed only faint superficial vascular markings. The lesion was mobile, non-tender, and there was no associated cervical lymphadenopathy as shown in Figure 1.

Figure 1 Pre-operative frontal and basal view.

Laboratory examinations

All labs were within normal range, including complete blood count, coagulation profile, liver function test, and kidney function test.

Imaging examinations

A contrast-enhanced computed tomography scan demonstrated a 10 mm × 10 mm, well-defined, avidly enhancing soft-tissue mass consistent with a vascular lesion. No bony erosion or intranasal extension was observed as shown in Figure 2. Based on these findings, surgical excision under local anesthesia was recommended for both diagnosis and treatment.

Figure 2 Computed tomography imaging. A: Axial view; B: Coronal view; C: Sagittal view.

FINAL DIAGNOSIS

Non-infiltrative angiolipoma.

TREATMENT

Complete surgical removal with alar base reconstruction (Figure 3).

Figure 3 Intraoperative photos show.

OUTCOME AND FOLLOW-UP

The surgical site healed uneventfully with a satisfactory cosmetic outcome, and the patient continues to be followed up in our clinic with no sign of recurrence (Figure 4).

Figure 4 One year post-operative frontal and basal view show.

DISCUSSION

Angiolipomas of the head and neck are infrequently encountered, and nasal involvement is even more uncommon. It most usually occurs in the limbs, whereas involvement of the head and neck is unusual and nasal presentation is extraordinarily rare[2,6]. Only a few nasal instances have been reported, typically affecting the nasal dorsum or tip[3,4,7]. There are a few isolated cases in the literature that involve the nasal tip or dorsum[3,4], but none that originate from the nasal alar base. Analysis of angiolipoma presentations reveals that head and neck cases constitute a very small minority, with the majority of lesions occurring in the extremities[8-10].

Radiologically, angiolipomas often present as well-defined enhancing lesions due to their vascular component; imaging findings are nonspecific and overlap with those of lipoma, hemangioma, and other vascular lesions[2,11]. Therefore, the diagnosis is based on histopathologic examination. Histology in this instance showed mature adipocytes with intermixed vascular channels and α-smooth muscle actin positivity limited to the vascular walls, consistent with a non-infiltrating angiolipoma (Figures 5 and 6).

Figure 5 Histopathologic findings of the nasal alar base mass. A: The tumor comprises a lot of blood vessels, adipocytes, and entrapped skeletal muscle fibers (asterisks); B: Higher magnification shows thin- and thick-walled blood vessels (arrows) and mature adipocytes. No cytological atypica or mitosis. Entrapped skeletal muscle fibers (asterisks) are noted. Hematoxylin and eosin staining. Scale bars measure A: 200 μm; B: 100 μm. AD: Adipocytes.

Figure 6 Immunohistochemical staining of the nasal alar base mass. A: Most of the vascular wall (arrows) shows positive immunoreactivity for the alpha-smooth muscle actin. Entrapped skeletal muscle fibers (asterisks) show negative immunoreactivity; B: Most of the small blood vessels show negative immunoreactivity for desmin, but large sized blood vessels (arrows) and entrapped skeletal muscle fibers (asterisks) show positive immunoreactivity. Scale bars measure 100 μm.

According to Dionne and Seemayer[12], angiolipomas are categorized as either non-infiltrating or infiltrating, with the latter exhibiting muscle invasion and a greater risk of recurrence. The lesion in this case was non-infiltrating, which is why surgical removal was simple and the result was favorable. Complete local excision is considered curative, and recurrence is rare when the entire tumor is removed[6]. In this case, the histologic identification of mature adipocytes with intermixed vascular channels, supported by alpha-smooth muscle actin staining, confirmed the diagnosis. Importantly, the lesion was non-infiltrating, which explains the simplicity of surgical removal and the lack of postoperative sequelae.

CONCLUSION

The clinical, radiologic, and histopathologic findings emphasize the importance of considering angiolipoma in the differential diagnosis of well-defined vascular-appearing nasal lesions. Continued reporting of such rare presentations will enhance our understanding and support more accurate diagnosis of these unusual lesions.