General Natbalie

Case

S#{233}guin,MD2

of the Charles

Day1

Peterfy,

#{149}

MD,

PhD

HISTORY

U

A 42-year-old man presented with a 6-year history of recurrent polyarticular pain, stiffness, and swelling of the hands, wrists, knees, and feet. Results from initial nadiographs were normal.

#{149} Robert

G. Dussault,

MD

On a recent follow-up visit, he complained of recurrent symptoms. Radiographs of the feet (Fig 1), hands (Fig 2), and knees were obtained. Computed tomography (CT) (Fig 3) and magnetic resonance (MR) imaging (Fig 4) of the feet, as well as bone scintigraphy of the

Figures 1, 2. (1) Posteroanterior radiographs of the left (a) and right

(b) feet. (2a) Posteroantenior graph of the left hand shows tissue

nodule

on the

the wrist (arrows) anterior radiograph hand demonstrates lytic lesion of the

.

ulnar

radioa softaspect

of

(2b) Posteroof the right an intraosseous

hamate

bone

(ar-

rows).

la

lb.

Index

terms:

Arthritis,

RadioGraphica I

From

1992;

the

Department

rheumatoid,

40.712

#{149}Joints, 40.12

12:203-206 ofRadiology,

H#{244}tel.Dieu de Montr#{233}al, Montreal,

and

Montr#{233}al University

ology, McGill University, Montreal (C.P., R.G.D.). From the 1991 RSNA scientific Address reprint requests to R.G.D.. Department of Radiology. Montr#{233}al (,encral 2 Current address: Department of Radiology, H#{244}pital Notre Dame, Montreal. C

January

RSNA,

1992

assembly. Hospital.

(N.S.,

R.G.D.)

and

the

Department

Received October 2, 1991; accepted 1650 Cedar, Montreal, Que, Canada

of RadiOctober H36

24. 1A4.

1992

S#{233}guinet a!

U

RadioGrapbics

U

203

4b.

5. 3-5.

Figures

MR images

feet

and

biopsy

taneous

ofboth

(3) Axial CT scan of both feet. (4) Coronal feet. (5) Bone scintigrams ofthe right

ankles

(Fig

specimen

5), were

was

nodule

performed.

obtained

in his left

(b) spin-echo

the ulnar aspect of the left wrist. Radiographs of the knees (not shown) demonstrated bilatenal joint effusions but no other abnormali-

A

from

T2-weighted (a) and Ti-weighted and left ankles and feet.

a subcu-

foot.

ties.

FINDINGS Radiognaphs of the feet (Fig ple, well-defined, juxtaarticular

A CT scan

U

1) showed multilyric lesions of

the metatarsophalangeal joints of both feet and interphalangeal joints of the great toes. These lesions predominated on the proximal side

of the

joints.

Many

of them

broke

through the adjacent marginal cortex, but none involved the articular surface. Some of the larger lesions had overhanging edges, while some smaller lesions resembled marginal erosions. Joint spaces were preserved, and there was no osteoporosis. No chondrocalcinosis on enthesopathic changes of the bones were evident. Radiographs of the hands (Fig 2) showed a well-defined, intraosseous lyric lesion of the right

204

U

hamate

RadioGraphics

bone

and

U

a soft-tissue

nodule

S#{233}guinet a!

on

niphenal,

of the

feet

intraosseous,

(Fig

3) showed

well-defined

pelow-atten-

uation lesions in the metatarsal heads. Some of the lesions broke through cortex. Synovial thickening of the metatarsophalangeal joints was visible. MR images showed lesions of the metatarsal heads, which exhibited low signal intensity with

spin-echo

Ti-weighted

pulse

sequences

and high signal intensity with T2-weighted sequences (Fig 4), consistent with fluid or inflamed synovium within the lesions. Scintigrams of the ankles and feet obtained with

technetium-99m

nate

(Fig

methylene

diphospho-

5) showed increased tracer activity in the left ankle and the metatarsophalangeal and proximal interphalangeal joints of both feet, consistent with active synovitis.

Volume

12

Number

1

DIAGNOSIS:

Cystic

rheumatoid

arthritis.

U DISCUSSION A diagnosis of rheumatoid arthritis can be made when at least four of the following critena of the American Rheumatism Association (1) are present: morning stiffness; swelling of three or more joints, particularly the wrist, metatarsophalangeal joints, or proximal interphalangeal joints, for at least 6 weeks; symmetric swelling; typical radiographic changes; rheumatoid nodules; and positive rheumatoid factor. Our patient had recurrent, symmetric polyarthritis and morning stiffness of several years duration. His initial physical examination 4 years before revealed a synovial cyst of the left wrist and a right knee effusion. Serum nheumatoid factor at that time was weakly positive. Erythrocyte sedimentation rate and serum concentration ofurates were normal. On the

basis

of the

tis was with

above

diagnosed. nonsteroidal

criteria, The

rheumatoid patient

was

rheumatoid

agents

is an

cortex,

of the

the

classic

can

marginal

cysts

the

marginal

lesions

grow,

overlying

surfaces.

be

At this

indistinguishable

erosions

rheumatoid

Similar

As the

through

at the

cystic

from

joint.

break

usually

stage,

accompanying

arthritis.

findings

have

been

described

in

rheumatoid arthritis seen in manual workers who maintain a high level of physical activity (3,4). This form has been termed rheumatoid arthritis of the robust reaction type (3). These patients,

usually

men,

cal and radiographic (with preservation osteoporosis),

also

exhibit

despite

associated

Debate

the

with

a poor

exists

over

arthritis

and

thritis

represent

ments

hinge

to which

cyst

cortex graphs

that

variant

on

the

an-

(2).

Argu-

relative

degree

of each.

The distinction and an intraos-

erosion

broke

through

is difficult to make are available. Such germane

rheuma-

dominate

a marginal

seous

cystic rheumatoid

erosions

picture

between

nheu-

prognosis.

primarily

diographic

pres-

and high traditionally

robust-type

and

clini-

of disease and limited

concurrent

whether

a similar

cysts

slow

progression ofjoint spaces

ence of subcutaneous nodules matoid factor titers-features

larly

unusual

side

eventually

the

the

na-

overlying

unless serial radioa caveat is particu-

to patients

with

robust-type

form of arthritis in which intraosseous cystic lesions are the dominant radiographic feature (2) Osteoporosis, osseous erosions, joint space narrowing indicative of cartilaginous destruction, and joint disruption are characteristically less prominent and develop later in

toms, generally do not seek help until late in the course of their disease. The distinction is largely of academic interest, since both conditions involve a relative lack of cartilage loss,

this

allow

.

variety

of the

disease.

Accordingly,

pa-

tients suffer less functional impairment. Gubler et al (2) estimate that 9% of patients with rheumatoid arthritis have the cystic form. Unlike classic rheumatoid arthritis, in which there is a female predominance of 2-3 : 1 , approximately 50% of patients with cystic rheumatoid arthritis are male. The age ofonset is similar to that of classic rheumatoid arthritis; however, radiographic abnormalities tend to appear later. Fifty percent of patients with cystic rheumatoid arthritis are senonegative, but they do not have changes characteristic of the senonegative spondyloarthropathies. Juxtaarticular, subcortical lytic lesions with well-defined sclerotic margins are the first osseous abnormality (2). The distribution of these lesions is typically symmetric and involves the same joints as classic rheumatoid arthritis: the wrist, metacarpophalangeal, and proximal

January

they

toid

treated

anti-inflammatory

arthritis

proximal

arthri-

and gold salts, with temporary improvement of his symptoms and normalization of the serum rheumatoid factor titer. The subcutaneous nodule of the left foot proved to be a synovial cyst. In conjunction with the radiologic findings, a final diagnosis of cystic rheumatoid arthritis was made. Cystic

and metatarsophalangeal and proximal interphalangeal joints of the feet. Lesions are located peripherally and predominate on the

1992

interphalangeal

joints

of the

hands

disease,

who,

experiencing

osteoporosis,

and

continued

clinically

joint

relevant

known.

increased companying ical

activity

the

joint

tively

may

through

unprotected

most

distinguish

form

the

in the synovial effusion and

result

thus

the

of rheu-

of subarticular

support

pressure a joint

are

that

classic

symp-

and

These

features

Some

mild

disruption

function.

both varieties from the matoid arthritis. The exact pathogenesis is not

only

theory

cysts that

space forceful

acphys-

in decompression

microfractunes marginal

of

in the cortex

nela-

weakened

by chronic inflammation (4). Synovial fluid and pannus thus intrude into subarticulan bone to form characteristic lesions. Growth of the cysts is ascribed to the development of a one-way valve mechanism between a cyst and the synovial cavity (4). There is a direct comelation between the size and extent of subarticular cysts and the level of activity to which a diseased joint is subjected (4,5). Synovial cyst formation represents an alternate pathway for

S#{233}guinet a!

U

RadioGrapbic.s

U

205

joint

decompression.

Accordingly,

an

distal

inverse

cartilaginous

destruction

and

prolong the functional is still not clear whether physical

activity

cystic

associated

rheumatoid

thus

with

arthritis

lesions

ultimately

integrity of the joint. the high degree of

It

robust-type

is directly

or

responsi-

ble for the relatively favorable clinical and madiographic outcome or whether these entities represent an inherently benign form of rheumatoid arthritis. This distinction has practical therapeutic ramifications in light of current trends in the use of exercise in the management of rheumatoid arthritis (7). Cystic nostic

rheumatoid

arthritis

problem.

or even

polyarticular

actenistic

can

Senonegative

be

a diag-

monoarticular

involvement

preservation

of articular

with

char-

space

and

eliminates

Monoarticular mimic

the

possibility

cystic

pigmented

rheumatoid

other quired

synovial tumors. to establish the

Cystic

rheumatoid

arthritis

atic,

may

begin

as a

lesions.

206

U

rarely The

RadioGraphics

generally

detected hand,

in the

particularly

U

asymptom-

absence the

middle

S#{233}guin Ct a!

of skin and

joints,

site

can

and

of

produce

juxtaarticular

soft

REFERENCES .

Schumaker HR. Primer on the rheumatic diseases. 9th ed. Atlanta: Arthritis Foundation, 1988; 317. Gubler FM, Maas M, Dijkstra PF, Rob deJongh

H.

3.

4.

Biopsy may be nediagnosis. Although

arthritis

is uncommon,

and

2.

5.

on

monoarticulan on asymmetric process, a symmetric distribution usually develops and the correct diagnosis is possible. The differential diagnoses of polyarticulan erosions and cysts with preserved joint space must also include sancoidosis, amyloidosis, multicentnic reticulohistiocytosis, and hypenlipoproteinemia. Osseous involvement in sancoidosis

1

can

synovitis

in bone,

predominant

Amyloidosis

eral, symmetric, erosive arthritis without joint space loss that has a predilection for the interphalangeal joints, particularly the distal joints, of the hands and feet. Polyarthritis is the first manifestation of the disease, followed months later by nodular eruptions of the skin (9). In hypenlipoproteinemia, well-defined, intraand extnaarticular erosions are also seen from xanthomas, which produce eccentric, noncalcified masses (9).

of gout.

villonodular

is the

(9).

tissues. Articular lesions are characterized by bulky masses associated with erosions, cysts, and preserved joint space. Changes are frequently bilateral and involve the shoulders and wrists (9). Multicentnic reticulohistiocytosis is a systemic disease associated with bilat-

U

lack of osteoporosis is most commonly misdiagnosed as gout (8). This is particularly true in cases in which large intraosseous cysts break through the overlying marginal cortex and simulate the appearance of overhanging edges. Diagnosis is further complicated in some patients with mildly increased serum unate levels and a favorable response to colchicine. The absence ofurate crystals in a sample of synovial fluid from the affected joint

phalanges,

involvement

correlation exists between the presence of subarticular cysts and synovial cysts (6). Decompression of an inflamed joint by either of these mechanisms may result in decreased

6.

7.

8.

9.

Cystic

rheumatoid

arthritis:

description

of

a nonerosive form. Radiology 1990; i77:829834. De Haas WH, De Boer W, Griffloen F, OostenElst P. Rheumatoid arthritis of the robust reaction type. Ann Rheum Dis 1974; 33:81-84. Jayson MN, Rubenstein D, Dixon AJ. Intraarticular pressure and rheumatoid geodes (bone “cysts”). Ann Rheum Dis 1970; 29:496-502. Castillo BA, Sallab BA, ScottJT. Physical activity, cystic erosions, and osteoporosis in rheumatoid arthritis. Ann Rheum Dis 1965; 24:522527. Genovese GR, Jayson MW, Dixon AJ. Protective valve of synovial cysts in rheumatoid knees. Ann Rheum Dis 1972; 3 1:179-183. HicksJE. Exercise in patients with inflammatory arthritis and connective tissue disease. Rheum Clin North Am 1990; 16:845-870. Chopra M, Chib P. Arthritis robustus: an unusual form of rheumatoid arthritis masquerading as gout. J Assoc Physicians Indice 1986; 34: 216-218.

Resnick

D.

Bone

and joint

phia: Saunders, 1989; 701-702, 1212-1217.

683-685,

imaging.

Philadel-

692-694,

Volume

12

Number

1