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Year : 2012  |  Volume : 60  |  Issue : 6  |  Page : 644--645

Posterior interosseous nerve palsy due to parosteal lipoma

Yasuhiro Seki, Yuko Hoshino, Hiroshi Kuroda 
 Department of Orthopedic Surgery, Kameda Medical Centre,Chiba, Japan

Correspondence Address:
Yasuhiro Seki
Department of Orthopedic Surgery, Kameda Medical Centre,Chiba

How to cite this article:
Seki Y, Hoshino Y, Kuroda H. Posterior interosseous nerve palsy due to parosteal lipoma.Neurol India 2012;60:644-645

How to cite this URL:
Seki Y, Hoshino Y, Kuroda H. Posterior interosseous nerve palsy due to parosteal lipoma. Neurol India [serial online] 2012 [cited 2020 Aug 12 ];60:644-645
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Full Text


A 67-year-old woman presented with a 2-month history of difficulty actively extending her fingers at the metacarpophalangeal (MP) joints of the left hand and a 10-year history of a mass in the lateral aspect of the left proximal forearm. Physical examination revealed no active extension of either the middle or ring finger at the MP joint and only slight active extension of both index and little finger at the MP joints. All the finger joints had full range of passive movement. There was normal active extension of the thumb and wrist. There was no sensory deficit. A soft mass of approximately 6 cm in diameter was noted in the proximal forearm. Magnetic resonance imaging (MRI) demonstrated a fatty lesion around the radial neck [Figure 1]a. We diagnosed the patient with posterior interosseous nerve palsy due to a fatty tumor and performed surgery. Via an anterior approach, we confirmed that the posterior interosseous nerve and superficial branch of the radial nerve were mildly compressed by the fatty tumor. The arcade of Frohse however, was found to entrap the posterior interosseous nerve. After the arcade of Frohse was cut [Figure 1]b, the tumor on the radial neck was extirpated (marginal excision) [Figure 1]c. The histological diagnosis was a lipoma. Nine months after the surgery, her extensor function had completely recovered, and now two years after the surgery there has been no recurrence of the tumor.

A parosteallipoma is rare and accounts for 0.3% of all lipomas. [1] It is difficult to identify the lesion as it is located deeply. However, when the tumor occurs around the radial neck, it can cause posterior interosseous nerve palsy under the arcade of Frohse. [1],[2] Although the finger function in our patient recovered completely, a case that showed no functional recovery after tumor excision was reported. [2] An additional functional reconstruction such as a tendon transfer may be necessary, depending on the period and degree of the nerve palsy as well as the patient's age.{Figure 1}


1Hamdi MF, Aloui I, Allagui M, Abid A. Paralysis of posterior interosseous nerve caused by parosteallipoma. Neurol India 2010;58:319-20.
2Sakamoto A, Yoshida T, Mitsuyasu H, Iwamoto Y. Lipoma causing posterior interosseous nerve palsy or superficial radial nerve paraesthesia. J Hand Surg Eur Vol 2011;36:76-7.