Giant Angioleiomyoma of Knee Presenting as Painless Ulcer: The First Case Report

Abstract

Angioleiomyomas are benign tumors originating in the vascular smooth muscle. The tumor typically presents as painful, solitary, small (<2 cm), slow growing, subcutaneous nodule. Angioleiomyoma of the knee is rare, and only few cases have been reported so far. We have described herein a giant angioleiomyoma of the knee presenting as a painless ulcer in a 22-year-old man. There was no intra-articular extension of the tumor, and total excision was curative. This is the first case report of giant angioleiomyoma of the knee as well as the first case report of angioleiomyoma presenting as a painless ulcerative lesion.

What was known?

Angioleiomyoma of the knee is rare, and it presents as a small painful nodule in middle-aged females. Giant angioleiomyoma of the knee or angioleiomyomas presenting as ulcerative lesion have not been reported in the literature.

Introduction

Angioleiomyoma is a benign soft tissue neoplasm that originates from smooth muscle in the tunica media of arteries and veins. It can occur anywhere in the body, with predilection for the lower extremity, and can be found in the dermis, subcutaneous fat, or fascia. The tumor typically presents as a painful, solitary, small (<2 cm), slow growing, firm, mobile, subcutaneous nodule. Angioleiomyoma of the knee is rare and only few cases have been reported so far. Herein, we have described the first case report of giant angioleiomyoma of the knee with atypical presentation as a painless ulcer and have discussed the surgical management of the same.

Case Report

A 22-year-old male presented with a painless ulcer of 2 year's duration on his left knee [Figure 1]. The lesion started as a small ulcer and gradually increased in size over the next 2 years. It was neither preceded by trauma nor associated with systemic symptoms like fever or weight loss. The patient had no past history of tuberculosis or visceral leishmaniasis. There was no past history of surgery on the affected knee. On examination, the ulcer was 10 × 8 cm in size, situated on the left knee, well-demarcated, non-tender, and was not fixed to any underlying structure. There was no lymphadenopathy and systemic examination was unremarkable. Incisional biopsy from the ulcer was suggestive of angioleiomyoma and excision was planned.

Figure 1.

Pre-operative photograph showing the giant (10 × 8 cm) ulcerative lesion on the patient's left knee

Total excision of the lesion with ligation of the feeder vessel, performed under general anesthesia, resulted in a large defect and exposure of the knee joint capsule [Figure 2]. However, no intra-articular extension of tumor was found intraoperatively. The resulting defect was covered by raising an anteromedial thigh fasciocutaneous flap based on septocutaneous perforator, and the donor site defect was closed primarily [Figure 3]. Post-operative recovery was uneventful.

Figure 2.

The defect after excision of the tumor

Figure 3.

Immediate post-operative photograph of reconstruction of the defect

On microscopic examination, the tumor sections showed interlacing fascicles of smooth muscle cells encircling vascular lumina lined by normal-looking endothelial cells [Figure 4]. No area of necrosis or hemorrhage was seen and mitotic activity was absent. The histopathological findings were consistent with that of an angioleiomyoma of the solid type. Immunohistochemistry confirmed the diagnosis, the tumor being positive for smooth muscle actin (SMA), desmin, and vimentin, and negative for HMB45. There has been no recurrence at 1 year follow-up, and the aesthetic outcome of surgery is satisfactory [Figure 5].

Figure 4.

Photomicrograph showing the tumor composed of numerous fascicles of smooth muscle cells encircling blood vessels H and E, ×40

Figure 5.

Aesthetic outcome after 1 year of surgery

Discussion

Angioleiomyomas account for 5% of all benign soft tissue neoplasms.[1] The tumor usually presents in the third to fifth decade of life and has female preponderance. They have a predilection for the lower extremities, and the commonest site is the lower leg. The typical lesion is a solitary, small, slowly growing, firm, mobile, subcutaneous nodule. Majority of the tumors (> 80%) are < 2 cm in size.[2,3] Pain, often paroxysmal, is the most striking clinical feature of angioleiomyoma and is present in about 60% of cases.[2,3] There are three histological types, namely solid, venous, and cavernous. It is considered in the differential diagnosis of painful nodular lesions of the extremity.

Angioleiomyoma of the knee is rare, with only a few case reports in the literature.[4,5,6,7,8] A case of intra-articular angioleiomyoma of the knee joint has also been described.[9] All the patients described in these case reports were middle-aged females.

Our case has the following unique features as compared to the other reported cases of knee angioleiomyoma: (1) male patient; (2) relatively younger age of presentation; (3) giant size of angioleiomyoma of knee; (4) presentation of angioleiomyoma as ulcerative lesion; and (5) absence of pain.

To our knowledge, this is the first case report of giant angioleiomyoma of the knee. More importantly, cases of angioleiomyoma presenting with an ulcerative lesion have never been described before. After an extensive literature search, we did not come across a single case report of angioleiomyoma of knee that presented with ulcerative lesion.

Finally, majority of angioleiomyomas of the lower extremity are painful, whereas, in our case, the tumor grew to a massive size but remained painless throughout.

Our case highlights for the first time the fact that angioleiomyomas may atypically present as an ulcerative lesion, rather than as a typical subcutaneous nodule.

What is new?

This is the first case report of giant angioleiomyoma of the knee, presenting uniquely as a painless ulcer. This case also highlights that angioleiomyomas may atypically present as ulcerative lesion, rather than as a typical subcutaneous nodule.