Mucous cysts of the DIPJ
Mucous cyst DIPJ
• Ganglion cyst of the DIPJ
• Usually occurs between the fifth and seventh
decades
• Associated with osteophytes or spurring of the
DIPJ
• Osteoarthritis in other joints
Ganglion/Mucous cyst
• Single or multiloculated cyst which appears smooth, white &
translucent
• Wall is made up of compressed collagen fibres and is sparsely
lined with flattened cells without evidence of an epithelial or
synovial lining
• Mucin-filled “clefts” from the capsular attachment of the main
cyst interconnect with the adjacent underlying joint via
tortuous continuous ducts
• Stroma may show tightly packed collagen fibres or sparsely
cellular areas with broken fibres and mucin-filled intercellular
& extracellular lakes
• No inflammatory reaction or mitotic activity has been noted
Ganglion/Mucous cyst
• Contents of cyst characterized by a highly viscous, clear, sticky,
jelly-like mucin made up of glucosamine, albumin, globulin, &
high concentrations of hyaluronic acid
• Aetiology & pathogenesis remain obscure
• Most widely accepted theory - mucoid degeneration
associated with degeneration of joint capsule or tendon
sheath
• Injury & mechanical irritation may stimulate production of
hyaluronic acid to form mucin, which may penetrate joint
ligaments and capsules and then coalesce to form cyst
Clinical signs
• Longitudinal grooving
of the nail - earliest
sign without a visible
mass, caused by
pressure on the nail
matrix
Clinical signs
• Enlarged cyst with
attenuated overlying
skin
Clinical signs
• Cyst (3-5mm) usually
lies to one side of the
extensor tendon and
between the dorsal
distal joint crease &
the eponychium
Clinical signs
• Often has Heberden’s
nodes and
radiographic evidence
of osteoarthritic
changes in the joint
Treatment
• Primarily surgical
• Numerous alternative treatment reported in
the past with moderate success:
– Intralesional injection - eg. Sodium morrhuate,
triamcinolone
– Occlusive flurandrenolone tape
Surgical Management
• Excision of the cyst alone
• Wide excision of the cyst along with
surrounding adjacent structures - eg.the
overlying skin, osteophyte debridements
• Debridement of the DIPJ osteophytes only,
without excision of the cyst itself or overlying
skin
Operative technique
• L-shaped / H-shaped /
curved incision
• Elliptical excision of
attenuated or involved
skin
Operative technique
• Cyst mobilized, traced to
the joint capsule &
excised with the joint
capsule
• All tissue excised between
the extensor tendon & the
adjacent collateral
ligaments
• Insertion of the extensor
tendon and the nail
matrix must be protected
Operative technique
• Excison of
osteophytes
• Skin closure may
require rotation /
advancement dorsal
skin flap or a fullthickness graft
Alternative approach
• Transverse incision
centred over DIPJ
• Base of mucous cyst
identified & excised while
leaving the distal &
superficial portion of the
cyst intact
• Excision of osteophtyes &
joint capsule with direct
skin closure
• Allow several weeks for
involution of the
remaining cyst
Complications
Residual nail deformities
Stiffness
Skin necrosis
Recurrence:
- inadequate excision
- ganglion extension to the other side of extensor
tendon
- persistent underlying arthritic process