Ⅰ. INTRODUCTION

Angiolymphoid hyperplasia with eosinophilia (ALHE) is a rare benign vascular neoplasm that was first reported by Wells and Whimster in 1969¹⁾. It is characterized by vascular proliferation lined by histiocytoid or epithelioid endothelial cells with inflammatory infiltrate of lymphocytes, plasma cells and eosinophils²⁾. ALHE may occur as solitary or multiple lesions having clinical appearance of pink to reddish- brown dome-shaped papules or nodules, and it is commonly found in the skin of head and neck region^1,3). However, ALHE in the oral mucosa is extremely rare, and only few cases of ALHE in the oral mucosa have been published so far. In this paper, we would like to discuss the histopathological features, diagnosis and treatment of ALHE through a case that occurred on the upper lip of a 46-year-old male.

Ⅱ. CASE REPORT

A 46-year-old male with no specific underlying disease or family history visited the Department of Oral and Maxillofacial Surgery, Seoul St. Mary’s hospital with a chief complaint of painless swelling on the right upper lip. History taking of the patient revealed that it occurred after the patient bit his right upper lip about 1 year ago, which gradually increased over time. Upon clinical examination, smooth, pale pink, firm nodule having a diameter of about 1.5cm was observed on the mucosal surface of the right upper lip (Fig. 1). Through clinical examination and the patient’s previous history of trauma, provisional diagnosis of irritation fibroma was made. For definitive diagnosis, excisional biopsy of the lesion was performed under local anesthesia. The specimen was a smooth and firm mass with a size of 1.5 x 1.0cm (Fig. 2). Based on histopathological findings, the lesion was confirmed as angiolymphoid hyperplasia with eosinophilia (ALHE). Extensive inflammatory infiltration and proliferation of small blood vessels surrounded by inflammatory cells including lymphocytes, neutrophils, eosinophils, and plasma cells were observed (Fig. 3A). The vessels were lengthened in the form of tubules, and the plump endothelial cells were protruding into the lumen. Endothelial cells were epithelioid with abundant eosinophilic cytoplasm and prominent nuclei (Fig. 3B).

The patient visited the hospital 6 months after the excision, and a similar mass was found on the upper lip with smaller size than before. The patient stated that there was a palpable mass after the excision, but he decided to leave it alone since it was clinically invisible. Accordingly, surgical excision of the lesion was performed under local anesthesia, and 0.8 x 0.5cm mass was excised (Fig. 4). Histopathological diagnosis again revealed that the recurrent lesion was ALHE. Although long-term follow-up should be carried out, there has been no evidence of recurrence after excision, and the patient is satisfied with the outcome.

Ⅲ. DISCUSSION

ALHE is a rare vascular disease whose etiology and pathogenesis are not clearly identified⁴⁾. Histopathologically, it is a benign vascular proliferative disease characterized by extensive infiltration of inflammatory cells. Eosinophils, lymphocytes and plump endothelial cells are mainly observed in the lesion⁵⁾. The plump endothelial cells have morphological characteristics of epitheloid or histiocytoid. In addition, they have an eosinophilic cytoplasm and show protrusion into the lumen of blood vessels⁶⁾.

ALHE was reported to be more prevalent in men, but now it appears to be more prevalent in women, particularly middle-aged women⁶⁾. ALHE of the oral mucosa is known to occur frequently in men aged 35 years on average, and it has been reported that the upper lip is the most common location, followed by buccal mucosa, palate, and tongue⁷⁾. In our case, the mass, which was thought to be a solitary lesion, was located on the upper lip mucosa. However, there was probably a smaller papule that was barely noticeable beside the main mass.

Although the etiology of ALHE is not clarified, a significant proportion of ALHE occurring in soft tissue arises secondarily in response to arteriovenous damage and repair procedures. These injuries are mainly due to previous trauma, and in rare cases arteriovenous malformations^3,7). According to Fetsch et al., arteries and veins were associated with 63% of masses, and in many cases, damage to blood vessels, discontinuity of internal elastic lamina, and disruption of murals were observed⁸⁾. Also, Olsen et al. found that arteriovenous shunt was present in 42% of AHLE patients and pointed out that arteriovenous shunt was the cause of the lesion³⁾. In this case, the cause of the lesion is presumed to be trauma to the upper lip and the resulting vascular damage.

Differential diagnosis of ALHE consists of pyogenic granuloma, Kaposi's sarcoma, and Kimura's disease. ALHE should be differentiated from Kimura's disease, in particular, since they are clinically and histopathologically similar^6,9). Kimura's disease and ALHE both appear in the form of chronic inflammation and occur frequently in the head and neck¹⁰⁾, especially the skin around the ears¹¹⁾. Although inflammatory infiltrates involving large amounts of eosinophils are commonly prominent, they can be distinguished histopathologically ⁹⁾. Kimura’s disease is characterized by distinct lymphoid follicles and surrounding fibrosis¹¹⁾, whereas ALHE is characterized by significant vascular changes with swollen and proliferated vascular endothelial cells^3,13). In addition, Kimura’s disease is accompanied by peripheral eosinophilia, elevated serum IgE levels, and lymphadenitis, whereas ALHE is rarely accompanied by peripheral eosinophilia and is not manifested by lymphadenitis¹⁴⁾.

Although the prognosis may vary depending on the time of onset, the presence of symptoms, and the multiplicity of lesions, it is known that ALHE rarely recurs when the lesion is completely excised¹⁵⁾. ALHE undergoes a benign course, and no malignant transmutations or metastasis have been reported so far. Some cases of recurrence have been reported in cases of incomplete resection^6,16). Therefore, in the case of refractory ALHE showing multiple lesions, surgical excision seems to be the optimal treatment¹⁶⁾. According to previous reports, various treatment modalities other than surgical approach can be applied. Systemic or intralesional corticosteroid injection, radiation therapy, chemotherapy, cryotherapy, laser therapy (pulsed dye, CO₂ etc.), methotrexate administration may be considered^6,17,18). These alternative treatment modalities have been reported to show varying levels of success rate considering the diversity of lesions¹⁶⁾. However, among these treatment modalities, complete surgical excision of ALHE is recommended as a desirable treatment in consideration of its recurrent nature ¹⁹⁾. In our case, only surgical resection using electrocautery was performed, but the lesion recurred. In previous studies, there were cases where the lesion recurred even after complete resection²⁾. There may have been an additional lesion which was unnoticed due to its size, or it may have recurred because the mass is nonencapsulated. In this case, there was no evidence of recurrence after second surgical excision of the lesion with no esthetic complications (Fig. 5). However, with the possibility of relapse in mind, continuous follow-up examination is required.