Skeletal Radiol (1997) 26:443–445 © International Skeletal Society 1997

&roles:Toshibumi Kinoshita Kiyoshi Ishii Yoshinori Abe Hiroshi Naganuma

T. Kinoshita, M.D. · K. Ishii, M.D. Department of Radiology, Sendai City Hospital, Sendai, Japan Y. Abe, M.D. Department of Orthopedics, Sendai City Hospital, Sendai, Japan

Case report A healthy 61-year-old woman with no antecedent trauma presented with a 10-year history of a slowly growing, painless mass in the right planta. She could not comfortably wear her right shoe. She did not complain of tenderness. The mass was elastic and hard, and was located in the subcutaneous tissue. The overlying skin was not thinned or discolored. Laboratory investigation disclosed no abnormality. MR imaging showed a welldemarcated subcutaneous soft tissue mass beneath the medial compartment of the plantar muscle (Figs. 1–3). On T1-weighted MR images, curvilinear lesions of signal loss were noted within the mass, which was iso-intense with muscle (Fig. 1). The soft tissue mass had heterogeneous high signal intensity on T2weighted MR images (Fig. 2). After administration of contrast agent, homogeneous contrast enhancement was evident within the mass on T1weighted images (Fig. 3).

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C A S E R E P O RT

Angiomyoma of the lower extremity: MR findings

H. Naganuma, M.D. Department of Pathology, Sendai City Hospital, Sendai, Japan

&kwd:Key words Angiomyoma · MRI&bdy:

T. Kinoshita, M.D. (✉) Department of Radiology, Akita Research Institute of Brain and Blood Vessels, 6–10 Senshu-Kubota Machi, Akita 010, Japan&/fn-block:

The excised tumor was a sharply circumscribed, whitish hard mass, 3 cm in diameter. Histological examination revealed numerous tortuous vascular channels with proliferation of spindle-shaped cells showing an interlacing band-like pattern (Fig. 4A). Admixed with these findings, fibrous components and edematous stroma were observed (Fig. 4B). Immunohistochemical staining for α smooth muscle actin was positive in the spindle-shaped cells. The pathological diagnosis was the solid type of angiomyoma. Fifteen months after surgery there was no recurrence.

Discussion Angiomyoma, also known as vascular leiomyoma, is a form of leiomyoma that usually occurs as a solitary subcutaneous lesion, with a predilection for the lower extremities of middle-aged women [1–4]. The most frequent complaint is simply of a tu-

mor mass [1]. As the tumor is situated in the feet, some patients complain of trouble in fitting on shoes [1]. Pain, with or without tenderness, is manifested in approximately 60% of patients [2]. The most satisfactory treatment for angiomyoma is complete excision [1]. Although the majority of angiomyomas are small tumors, ranging from 0.5 to 2 cm in diameter, they occasionally grow larger [1, 3]. Angiomyomas commonly arise in the deep layers of the dermis, or in the subcutaneous tissue [1]. The tumor is usually rounded, forming a nodule that generally elevates the skin [3]. Angiomyomas are histologically classified as solid, cavernous, or venous [2]. Microscopically, the solid type of angiomyoma is composed of intersecting smooth muscle bundles originating from medium-sized vessels that lack elastic fibers [5]. Curvilinear structures of low signal intensity on T1-weighted MR images are thought to correspond to tortuous

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Fig. 1 Coronal T1-weighted spin echo MR image (TR/TE 578/15 ms), through the level of the metatarsal, shows a well-demarcated soft tissue mass of slightly low signal intensity compared with muscle. Subcutaneous fat is obliterated by the mass. Curvilinear structures of signal loss (arrowheads) are noted within the mass&ig.c:/f Fig. 2 Coronal T2-weighted fast spin echo MR image (TR/TE 3400/96 ms), through the level of the metatarsal, shows the mass with heterogeneous high signal intensity&ig.c:/f Fig. 3 Coronal (A) and sagittal (B) contrast-enhanced T1-weighted MR images (TR/TE 623/17 ms), show homogeneous contrast enhancement within the subcutaneous mass&ig.c:/f

1

2

3A

A Fig. 4 A Histological features of the tumor include numerous vascular channels with proliferation of smooth muscle cells. B Edematous stroma with degeneration is observed

muscular vascular channels surrounded by smooth muscle bundles. The bulk of angiomyoma is composed of smooth muscle and fibrous tissue [3]. Areas of myxoid change

3B

B

and hyalinization are sometimes present [2]. It is probable that loose cellularity with edematous change tends to cause the prolongation of relaxation time in T2-weighted MR imaging. We suggest that the heterogeneity of signal intensity in the tumor on T2-weighted MR images reflects these histological appearances. Our case of angiomyoma had an unusual presentation, because angio-

myomas are usually small and tender. The MR features of this case could be present in cases of larger angiomyomas. Neurilemoma often occurs in the flexor surface of the lower extremities, showing a welldemarcated mass of high signal intensity on T2-weighted MR images [6]. However, prominent tortuous structures of signal void may suggest the diagnosis of angiomyoma.

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Angiomyoma should be considered when vascular structures are noted on MR examination of a welldemarcated soft tissue mass arising in the subcutaneous tissue of the lower extremities.

ANNOUNCEMENTS European Spine Society 8th Annual Meeting September 10–13, 1997 Kos, Hellas, Greece For further information please contact: E.P. Velikas, M.D. (Organizing Committee), 18 Ipsilandou Str.-Kolonaki, GR-106 76 Athens, Greece. Tel. (+30)1-7249050, Fax (+30)1-7241003; or J. Reichert Schild (Scientific Secretariat), Seefeldstrasse 16, CH-8610 Uster, Switzerland. Tel. (+41)1-9941404, Fax (+41)1-9941403.

References 1. Duhig JT, Path D, Ayer JP. Vascular leiomyoma: a study of 61 cases. Arch Pathol 1959; 68: 424–430. 2. Hachisuga T, Hashimoto H, Enjoji M. Angioleiomyoma: a clinicopathologic reappraisal of 562 cases. Cancer 1984; 54: 126–130. 3. Stout AP. Solitary cutaneous and subcutaneous leiomyoma. Am J Cancer 1937; 29: 435–469. 4. Freedman AM, Meland NB. Angioleiomyomas of the extremities: report of a case and review of the Mayo Clinic ex-

60th Annual Course: Radiology 1997 – Thoraco-Abdominal Imaging September 11–13, 1997 Minneapolis, MN, USA Fee: $395. For further information please contact: Office of Continuing Medical Education, University of Minnesota, Suite 107, 615 Washington Avenue S.E., Minneapolis, MN 55414, Tel.: (612)626-7600 or Toll Free 1-800-776-8636, Fax: (612)626-7766, Internet: http://www.cee.umn.edu:80/cme/ World Congress on Medical Physics and Biomedical Engineering September 14–19, 1997 Nice, France For further information please contact: Nice97, See, General Secretariat, 48 rue de la Procession, F-75724 Paris Cedex 15, France. Tel.: +33 1 44 49 60 60, Fax +33 1 44 49 60 44, e-mail: [email protected]. 2nd Interventional MRI Symposium October 17–18, 1997 Düsseldorf, Germany For further information please contact: PD Dr. Thomas Kahn, Institut für Diagnostische Radiologie, Heinrich-Heine-Universität, Moorenstrasse 5, D-40225 Düsseldorf, Germany. Tel. +49-(0)2 11-8 11-77 52/87 67, Fax +49-(0)2 11-8 11-61 45, e-mail: [email protected], http://www.mr.uni-duesseldorf.de

perience. Plast Reconstr Surg 1989; 83: 328–331. 5. Rosai J. Soft tissue. In: Rosai J (ed) Ackerman’s surgical pathology, 7th edn. St. Louis: Mosby, 1989: 1547–1633. 6. Cerofolini E, Landi A, DeSantis G, Meiorana A, Canossi G, Romagnoli R. MR of benign peripheral nerve sheath tumors. J Comput Assist Tomogr 1991; 15: 593–597.

VII Alex Norman Lectureship Series in Radiology: Advanced Musculoskeletal Imaging – The Shoulder December 9, 1997 New York, NY, USA Sponsored by: Hospital for Joint Disease, New York, NY, New York University School of Medicine. Faculty: D. Resnick, V. Chandnani, J. Beltran, J. Brown, N. Schoenberg, J. Zuckerman, A. Rokito, D. Rose, F. Cuomo, M. Rafü. Registration fee: Physicians $100, Residents/Technologists $50. For further information please contact: Ms. Cathy Smith, Tel.: (212)598-6373, Fax: (212)598-6125.