Clin Orthop Surg.  2013 Dec;5(4):334-337. 10.4055/cios.2013.5.4.334.

Glomus Tumor of Hoffa's Fat Pad and Its Management by Arthroscopic Excision

• Prabhakar
• Dhillon MS
• Vasishtha
• Bali K

• KMID: 1787038
• DOI: http://doi.org/10.4055/cios.2013.5.4.334

Abstract

We present a rare case of glomus tumor of Hoffa's fat pad in a 42-year-old woman. Magnetic resonance imaging findings along with the characteristic clinical picture led us to suspect a glomus tumor as the possible etiology. An ischemia test was found to be positive and this further substantiated our diagnosis. An arthroscopic excision was performed and the histology confirmed the diagnosis of glomus tumor of Hoffa's fat pad. The patient responded well to the excision with immediate complete resolution of pain and she remains asymptomatic at the last follow-up after 15 months. To our knowledge, this is the second reported case of glomus tumor of Hoffa's fat pad and the first ever to be managed by simple arthroscopic excision. The tumor poses a great challenge to an orthopedic surgeon. However, knowledge of its characteristic clinical presentation and the recognition of such a rare entity can help achieve an early diagnosis and timely management.

Keyword

Glomus tumor; Arthroscopy; Excision; Knee; Fat pad

MeSH Terms

Adipose Tissue/pathology/*surgery
Adult
Arthroscopy
Female
Glomus Tumor/*secondary
Humans
Knee/pathology/*surgery
Magnetic Resonance Imaging
Soft Tissue Neoplasms/*surgery

Figure

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  Fig. 1 Magnetic resonance imaging of the right knee showing a subcentimeter nodule at the inferior aspect of patella in the Hoffa's fat pad. The nodule was hypointense on T1-weighted images (A) and hyperintense on T2-weighted images (B). (C) Axial image confirmed location in the substance of fat pad.

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  Fig. 2 (A) Intraoperative arthroscopic view showing a pedunculated reddish brown nodule arising from Hoffa's fat pad. (B) The base of the nodule was revealed after careful shaving of part of fat pad.

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  Fig. 3 Photomicrograph (H&E, ×40) showing blood vessels (big arrow) surrounded by solid proliferation of round to cuboidal epitheloid cells with perfectly round nuclei and acidophilic cytoplasm (small arrow) characteristic of glomus tumor.

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  Fig. 4 Immunohistochemistry for smooth muscle actin showing diffuse cytoplasmic positivity (×20).

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