Lipoma of Guyon's canal causing ulnar neuropathy.

Abstract

Lipoma is a benign soft tissue tumor which rarely causes neuropathy. In closed compartments such as Guyon's canal, even small volume loss can lead to compression of nerve. Hence in such areas, even innocuous tumors such as lipomas can cause neuropathy and warrant surgery. We present one such case of ulnar neuropathy caused by lipoma of Guyon's canal.

Full text

Page 1

CASE REPORT
Lipoma of Guyon’s canal causing ulnar neuropathy
Seema Rohilla Æ Æ Rohtas K. Yadav Æ Æ
Dhara B. Dhaulakhandi
Received: 31 October 2008/Accepted: 19 April 2009/Published online: 26 May 2009
? Springer-Verlag 2009
Abstract
rarely causes neuropathy. In closed compartments such as
Guyon’s canal, even small volume loss can lead to com-
pression of nerve. Hence in such areas, even innocuous
tumors such as lipomas can cause neuropathy and warrant
surgery. We present one such case of ulnar neuropathy
caused by lipoma of Guyon’s canal.
Lipoma is a benign soft tissue tumor which
Keywords
Lipoma ? Guyon’s canal ? Ulnar neuropathy
Introduction
Lipoma is a benign pliable tumor composed of mature
adipocytes. It is one of the commonest benign tumors, but
rarely causes neuropathy. Very few cases of ulnar neu-
ropathy due to lipoma in Guyon’s canal have been reported
in literature.
Case report
A 36-year-old female presented with burning pain and
diminished sensations along the little finger and ulnar
aspect of the ring finger of right hand for 6 months. On
examination, there was a swelling on the hypothenar
eminence and fullness of medial aspect of wrist. The
swelling was soft but tense. There was atrophy of muscles
on hypothenar aspect of hand. The power of the little and
ring fingers was diminished.
Conduction velocity studies of the right ulnar nerve
showed prolonged distal motor latency from the wrist to
the abductor digiti minimi of 8 ms (normal\4.0 ms),
diminished motor conduction velocity of the ulnar nerve in
the elbow-to-wrist segment of 42 m/s (normal 45–75 m/s),
and prolonged distal sensory latency of 4.2 ms (nor-
mal\3.5 ms). Conduction velocity studies of the left ulnar
nerve were normal.
Ultrasound of the swelling showed a well-defined
echogenic mass in the hypothenar eminence. Subsequent
magnetic resonance imaging (MRI) showed a well-defined
lobulated mass hyperintense on both T1W and T2W ima-
ges and suppression of signal on STIR images s/o fat
(lipoma) (Fig. 1a–c). The mass was lying within the lateral
aspect of abductor digiti minimi muscle. Part of it was
insinuating between flexor tendons of the hand and meta-
carpals and another part was insinuating into zones 1 and 2
of Guyon’s canal (ulnar tunnel). The mass also extended
distally for a considerable distance along the deep branch
of the ulnar nerve. The ulnar nerve was stretched over the
mass in zone 2. The carpal tunnel was displaced radially
(Fig. 2a, b).
The patient was subsequently operated and the mass was
removed. Histopathology showed mature adipose tissue
consistent withlipoma.
uneventful with progressive resolution of symptoms and
good functional recovery.
The patient provided consent for the publication of this
case report.
Postoperativecoursewas
S. Rohilla ? R. K. Yadav
Department of Radiodiagnosis and Imaging,
Pt. B.D. Sharma Post Graduate Institute of Medical Sciences,
University of Health Sciences, Rohtak 124001, Haryana, India
D. B. Dhaulakhandi (&)
Department of Biotechnology and Molecular Medicine,
Pt. B.D. Sharma Post Graduate Institute of Medical Sciences,
University of Health Sciences, Rohtak 124001, Haryana, India
e-mail: BTMM.submissions@gmail.com
123
J Orthopaed Traumatol (2009) 10:101–103
DOI 10.1007/s10195-009-0051-9

Page 2

Discussion
Guyon’s canal (ulnar tunnel) is a fibroosseous tunnel along
the anteromedial portion of the wrist that contains the ulnar
nerve and artery. It extends from the palmar carpal ligament
at the proximal edge of the pisiform bone to the origin of the
hypothenar muscles at the level of hamulus [1]. The impor-
tance of the tunnel lies in the fact that it is a closed com-
partmentandanycompromiseinitsvolumecanleadtoulnar
nerve compression causing Guyon’s canal syndrome.
Guyon’s canal consists of three zones. Zone 1 is the
portion of the tunnel proximal to the bifurcation of the
Fig. 1 a T1W coronal images of hand showing a hyperintense mass in the region of hypothenar eminence and along medial aspect of hand.
b The mass is hyperintense on T2W images. c The mass shows suppression of signal on STIR images
Fig. 2 a Ulnar nerve stretched
by lipoma in zone 2 (arrow). b
Lipoma extending distally into
the wrist along the deep branch
of ulnar nerve
102J Orthopaed Traumatol (2009) 10:101–103
123

Page 3

ulnar nerve. Zone 2 encompasses the deep motor branch of
the nerve which is bounded superficially by the tendinous
arcade and deeply by the pisohamate ligament. Zone 3
surrounds the superficial branch consisting mainly of sen-
sory fibres [2]. Clinical symptoms correlate with the zone
in which ulnar nerve compression occurs: combined motor
and sensory deficits occur in zone 1 lesion, pure motor
deficits in zone 2 lesions, and isolated sensory deficits in
zone 3 lesions [3]. Our patient had both sensory and motor
ulnar neuropathies as there was compression in zone 1 and
also zone 2.
Compressive neuropathies of the ulnar nerve occur
mostly at elbow and less commonly at wrist [4]. Various
causes of ulnar nerve compression at wrist include gan-
glion, trauma, giant cell tumors, neurofibromas, intraneural
cysts, anomalous muscles, thrombosis, bursitis, and thick-
ened pisohamate ligament [2, 3]. Other rare causes of ulnar
nerve compression are lipoma [2], calcinosis in sclero-
derma [5, 6], localized nodular synovitis [7], uremic
tumoral calcinosis [8], following venipuncture [9], aneu-
rysm of ulnar artery [10], diffuse intramuscular hemor-
rhage [11], and arteriovenous malformation [12]. Lipoma
is a rare cause of neuropathy [13]. To the best of our
knowledge, only five cases of ulnar neuropathy due to
lipoma in Guyon’s canal have been reported to date. This is
the sixth case.
Lipoma is a soft tumor and does not normally compress
surrounding structures, but even it can cause compression
when occurring in a closed compartment such as ulnar
tunnel. Timely surgical removal can be curative in such
cases.
Conflict of interest statement
no conflict of interest related to the publication of this manuscript.
The authors declare that they have
References
1. Gross MS, Gelberman RH (1985) The anatomy of the distal ulnar
tunnel. Clin Orthop 196:238–247
2. Sakai K, Tsutsui T, Aoi M, Sonobe H, Murakami H (2000) Ulnar
neuropathy caused by a lipoma in Guyon’s canal—case report.
Neurol Med Chir (Tokyo) 40:335–338
3. Bui-Mansfield LT, Williamson M, Wheeler DT, Johnstone F
(2002) Guyon’s canal lipoma causing ulnar neuropathy. AJR
178:1458
4. Posner MA (2000) Compressive neuropathies of the ulnar nerve
at the elbow and wrist. Instr Course Lect 49:305–317
5. Thurman RT, Jindal P, Wolff WF (1991) Ulnar nerve compres-
sion in Guyon’s canal caused by calcinosis in scleroderma. J
Hand Surg Am 16(4):739–741
6. Chammas M, Meyer zu Reckendorf G, Allieu Y (1995) Com-
pression of the ulnar nerve in Guyon’s canal by pseudotumoral
calcinosis in systemic scleroderma. J Hand Surg Br 20(6):794–
796
7. Budny PG, Regan PJ, Roberts AH (1992) Localized nodular
synovitis: a rare cause of ulnar nerve compression in Guyon’s
canal. J Hand Surg Am 17(4):663–664
8. Garcia S, Cofan F, Combalia A, Campistol JM, Oppenheimer F,
Ramon R (2000) Compression of the ulnar nerve in Guyon’s
canal by uremic tumoral calcinosis. Arch Orthop Trauma Surg
120(3–4):228–230
9. Radji M, Zaarour J, Lhotellier F, Zakine J, Aihonnou T (2008)
Ulnar neuropathy following venipuncture. Ann Fr Anesth Reanim
27(1):114–115
10. Yoshii S, Ikeda K, Murakami H (1999) Ulnar nerve compression
secondary to ulnar artery true aneurysm at Guyon’s canal.
J Neurosurg Sci 43(4):295–297
11. Vijayakumar R, Nesathurai S, Abbott KM, Eustace S (2000)
Ulnar neuropathy resulting from diffuse intramuscular hemor-
rgahe: a case report. Arch Phys Med Rehabil 81(8):1127–1130
12. Ozdemir O, Calisaneller T, Altinors N (2000) Compression of the
ulnar nerve in Guyon’s canal by an arteriovenous malformation.
J Hand Surg Eur 32(5):600–601
13. Galeano M, Colonna M, Risitano G (2001) Ulnar nerve syndrome
secondary to lipoma of the hypothenar region. Ann Plast Surg
46(1):83–84
J Orthopaed Traumatol (2009) 10:101–103103
123