Eur J Plast Surg (1999) 22:40±43
F. Baptista ´ F. Margado ´ J.P. Guimares ´ P. Brazo
A. Cordeiro Ferreira
Inclusional body myositis localized to wrist and digital flexors
of the left upper limb
Received: 4 December 1997 / Accepted: 2 February 1998
F. Baptista ´ J.P. Guimares ´ P. Brazo ´ A. Cordeiro Ferreira (
Department of Plastic, Reconstructive and Maxillofacial Surgery,
Hospital de Santa Maria, Av. Prof. Agaz Moniz,
P-1699 Lisboa Codex, Portugal
Department of Neurology, Hospital de Santa Maria, Lisboa,
Abstract A clinical case of inclusion body myositis, an
infrequent type of inflammatory myositis, is reported. In
addition to the rarity of the disease, this case had a unique
clinical presentation. A full account of this condition is
presented, including its epidemiological aspects, clinical
presentation, etiopathogenesis, laboratory and histopatho-
logical findings, differential diagnosis and treatment.
Key words Inclusion body myositis ´ Wrist ´ Digital
The term Inclusion Body Myositis (IBM) was initially
used by Yunis and Samaha  in 1971, to designate a
type of myopathy which was clinically indistinguishable
from other forms of inflammatory myopathies but histo-
logically unique. It is characterized by the presence in
muscle fibers of vacuoles containing cytoplasmic degra-
dation products (rimmed vacuoles under optical micros-
copy and tubulofilamentous cytoplasmic and nuclear in-
clusions under electron microscopy [1, 2].
The pathogenesis of IBM is unknown. The role of in-
flammatory changes in the pathogenesis of this myositis is
still unclear, controversial and a matter of ongoing inves-
tigation. It remains unresolved as to whether it is a pri-
marily inflammatory myopathy, a dermatomyositis or
polymyositis or a myopathy in which inflammatory
changes play a secondary role [2, 3]. Some authors point
out the possibility of an additional neuropathic process,
but no conclusive results have been obtained so far .
Usually included among inflammatory myositis, this dis-
ease has gradually been recognized as a distinct entity .
Nevertheless, none of its clinical, morphological or elec-
tromyographic aspects is exclusive or specific to IBM.
Thus, the diagnosis requires a considertion of all these as-
pects in order to exclude other differential diagnoses.
Inclusion body myositis is a rare pathology, with only
a few cases described in world literature. Its etiologic
mechanisms are obscure and still undefined, and conse-
quently there has been a dramatic lack of favorable re-
sponse to most therapeutic programs.
A 19-year-old Caucasian male student was referred for evaluation of
progressive deformity of the left hand and wirst.
At birth a slight and diffuse enlargement of his left upper extrem-
ity at the level of the forearm and thenar eminence was noted by his
paediatrician. He was seen at the Orthopaedic Department, where
the enlargement was confirmed, with apparent normal function.
There were no other personal or familial facts of relevance.
At age 9, a progressive flexion deformity developed in the third
finger of the left hand, at the level of the metacarpophalangeal joint,
without any extension deficit. A similar deformity of the 4th, 2nd
and 5th rays occurred progressively (in that order). There were no
The deformity progressed, especially in the 3rd finger, and the
situation was considered to be a stenosing synovitis (trigger finger)
and was operated upon at the age of 13.
Due to the insidiously progressive nature of the condition, caus-
ing marked flexion of the wrist and fingers with limitation of active
extension, the patient was referred to the Plastic Surgery Department
of the Neurology Clinic for suspicion of neuromuscular pathology.
Biopsy of left forearm volar muscles was performed in Septem-
ber 1993. It revealed severe myositis, with significant variations in
muscle fiber diameter, some degenerating fibers undergoing phago-
cytosis, and others with an inflammatory infiltrate. Many of the fi-
bers showed rimmed vacuoles, suggesting inclusion body myositis
In January 1994, a biopsy of the proximal deltoid muscle was
performed and showed complete absence of pathologic findings
(Fig. 2). This confirmed the clinical hypothesis that only the left
forearm volar muscles were involved.
In addition to continuing rehabilitation, the patient was started on
botulinum toxin and showed a slight but temporary subjective im-
provement. The situation worsened after a few months, with marked
flexion of the wrist and fingers and severe retraction of wrist and fin-
ger flexor muscles, thus surgical correction was proposed. The pa-