Angiolipoma of the neck: a case report.

Abstract

Angiolipomas of the neck are extremely rare," to our knowledge, only 2 cases have been previously reported. We report a new case, which occurred in a 28-year-old woman. The mass was totally resected, and the patient showed no recurrence at the 18-month follow-up.

Introduction

Angiolipoma is a rare variant of lipoma; its distinctive feature is prominent vascularity. When it does occur, it is usually seen in young adults, and it has a predilection for the trunk and extremities. (1-3) Angiolipomas of the head and neck are especially rare; to the best of our knowledge, only 17 such cases have heretofore been reported in the English-language literature.(2-4) Most of these cases occurred in the salivary glands and facial skeleton; only 2 originated in the neck. In this article, we describe a new case of angiolipoma of the neck.

Case report

A 28-year-old woman was admitted to out department with a left neck mass that had been present for 2 years. She had noticed a slight increase in its size during the preceding 3 months. Physical examination revealed that a 10 x 7-cm, nontender, semimobile mass occupied the middle and lower two-thirds of the left neck (figure 1). The overlying skin was normal. No fluctuation or bruits were present. Findings on the remainder of the examination were normal. Magnetic resonance imaging (MRI) with heterogeneous contrast enhancement revealed that the well-defined mass extended from the level of the submandibular gland down to the thyroid gland (figure 2).

[FIGURES 1-2 OMITTED]

Based on these findings, an excisional biopsy was planned. Surgical exploration revealed that an encapsulated, fibrofatty nodular mass extended from the hyoid bone down to the supraclavicular fossa. Throughout the dissection, the presence of a very intense network of feeding vessels was noted; they were either ligated or cauterized without difficulty. The mass was totally resected without the need to sacrifice surrounding structures. The patient's postoperative course was uneventful, and she was discharged on postoperative day 3.

Macroscopically, the excised mass was identified as an encapsulated nodular lesion measuring 7 x 7 x 6 cm (figure 3). The cut surface was solid and yellow with a reddish tinge, and it had a lobular pattern. On microscopic sectioning, the lesion was made up of mature fat cells in highly cellular areas of active fibroblasts and vascular channels of different caliber (figure 4). Perivascular and interstitial fibrosis was also observed.

[FIGURES 3-4 OMITTED]

At the 18-month follow-up, no evidence of recurrence was found.

Discussion

Angiolipoma was first established as a distinct entity in 1960 by Howard and Helwig. (5) Microscopically, angiolipomas are made up of mature adipocytes and interspersed vascular structures lined with elongated endothelial cells. The proportion of fatty tissue can vary throughout a lesion, and the vascular component is frequently prominent adjacent to the capsule. The presence of fibrinous microthrombi is a distinctive feature that differentiates angiolipomas from other lipomas.

Based on studies by Dionne and Seemayer (6) and Lin and Lin, (7) angiolipomas are subdivided into two histologic types: infiltrating and noninfiltrating.

* Infiltrating angiolipomas are characteristically not encapsulated, and they infiltrate into surrounding tissue. Their clinical behavior is similar to that of hemangiomas. Infiltrating angiolipomas are usually diagnosed in older patients. The vast majority occur in the lower extremities or in the paraspinal region, which can lead to muscular pain and neural deficits. (1,2,4,8) In their study of 459 lipomas, Lin and Lin found that 25 (5.4%) met the criteria for angiolipoma (7) Two ofthe 25 angiolipomas were microscopically unencapsulated and showed some degree of infiltration into adjacent tissues.

* Noninfiltrating, or circumscribed, angiolipomas are encapsulated lesions limited to the subcutaneous compartment. Their size almost never exceeds 4 cm. These lesions are more common in young people, and they are equally distributed between the sexes.

The pathogenesis of angiolipomas remains unclear, but a history of trauma is found in most cases that do not involve the head and neck. Other proposed etiologic possibilities include fatty degeneration of a central hemangioma or vascular proliferation of a congenital lipoma. (2,9)

On physical examination, angiolipomas usually present as tender, subcutaneous nodules of white adipose tissue. They are rarely associated with overlying skin discoloration. The most common symptom is a constant, dull pain with associated neuropathies secondary to vascular engorgement and edema, which can lead to compression of the adjacent neural tissue. (3,4) Our patient had a non-tender, semimobile mass that occupied the middle and lower two-thirds of the left neck; neither skin discoloration nor pain was present.

The diagnosis of angiolipoma can be aided by computed tomography or MRI. On contrast-enhanced studies, angiolipomas demonstrate a marked enhancement as a result of their intense vascularity. Noncontrast studies demonstrate the homogenous low attenuation of a typical lipoma. (4) In out patient, MRI detected a well-defined mass with heterogeneous contrast enhancement.

The lesion in out patient was an example of a noninfiltrating angiolipoma, based on its encapsulation and characteristic microscopic findings, including a fibrotic stroma with myxoid degeneration and lobulated cellular areas characterized by patchy capillary vascularization and fibroblastic activity. There was no sign of malignancy, such as increased mitosis or cellular pleomorphism.

The treatment of both infiltrating and noninfiltrating angiolipomas is total surgical excision. The infiltrating type of lesion is associated with more treatment difficulties. These lesions have been reported to recur after surgical excision in 35 to 50% of cases. (6) Wide local excision with free margins is the preferred surgical procedure; in cases of inadequate excision, radiation therapy is necessary. (2,4) For noninfiltrating angiolipomas, simple excision is curative because these lesions have no tendency to recur following surgical removal.

References

(1.) Sanchez Aniceto G, Salvan Sacz R, Garcia Penin A. Angiolipoma of the cheek: Report of a case. J Oral Maxillofac Surg 1990;48: 512-15.

(2.) Alvi A, Garner C, Thomas W. Angiolipoma of the head and neck. J Otolaryngol 1998;27:100-3.

(3.) Reilly JS, Kelly DR, Royal SA. Angiolipoma of the parotid: Case report and review. Laryngoscope 1988;98(8 Pt 1):818-21.

(4.) Shohet JA, Simpson B, Coleman JR, Geiger XJ. Angiolipoma presenting as a nasal mass. Otolaryngol Head Neck Surg 1998;118: 848-9.

(5.) Howard WR, Helwig EB. Angiolipoma. Arch Dermatol 1960;82: 924-31.

(6.) Dionne GP, Seemayer TA. Infiltrating lipomas and angiolipomas revisited. Cancer 1974;33:732-8.

(7.) Lin JJ, Lin F. Two entities in angiolipoma. A study of 459 cases of lipoma with review of literature on infiltrating angiolipoma. Cancer 1974;34:720-7.

(8.) Matsuoka Y, Kurose K, Nakagawa O, Katsuyama J. Magnetic resonance imaging of infiltrating angiolipoma of the neck. Surg Neurol 1988;29:62-6.

(9.) Flaggert JJ III, Heldt LV, Keaton WM. Angiolipoma of the palate. Report of a case. Oral Surg Oral Med Oral Pathol 1986;61: 333-6.

From the Department of Otolaryngology (Dr. Saydam, Dr. Bozkurt, Dr. Ugur, and Dr. Ozcelik) and the Department of Pathology (Dr. Kutluay), Bayindir Hospital, Ankara, Turkey.

Reprint requests: Levent Saydam, M D, Associate Professor, Department of Otolaryngology, Bayindir Medical Center, Sogutozu, Ankara, Turkey. Phone: [phone]; fax: [phone]; e-mail: [e-mail]