Differential diagnosis of cutaneous and subcutaneous myxoid lesions

sex ration (F:M)

typical age (years)

site of predilection

differential diagnosis

histopathology

Benign lesions

myxoid dermatofibroma

F>M

30-50

lower extremities

cutaneous myxoma

acanthosis,
storiform pattern,
peripheral sclerosis,
variable factor XIIIa and SMA positivity

cutaneous focal mucinosis

F=M

20-50

face>trunk>extremities

mat be a variant of myxoid dermatofibroma or an early cutaneous myxoid cyst

loose dermal collagen,
peripherally accentuated fibroblasts

cutaneous myxoid cyst

2:1

>10

fingers

probably a variant of ganglion

as cutaneous focal mucinosis, plus cyst formation

trichodiscoma

F=M

30-50

face

follicular neoplasm of sebaceous mantle zone

angiomyxoma

F=M

15-30

face (eyelids, ear)

often multiple,
lobulated,
vascular,
+/- epithelial component,
frequent perivascular neutrophils

cellular myxoma of soft tissue

F>M

25-85

extremities, usually deep but may be superficial

intramuscular myxoma, low-grade myxofibrosarcoma

cellular and vascular but lacking pleomorphism, lacks curvilinear vessels

juxtra-articular myxoma

1:3

30-50

knee

probably a low-grade variant of myxofibrosarcoma

subcutaneous,
vaguely lobular,
often cystic

dermal fasciitis

F<M

10-20

head & neck

well-circumscribed papule with collarette

myxoid spindle cell lipoma

F<M

45-65

neck & shoulder

myxoid liposarcoma

multilobular,
adipocytes

myxoid leiomyoma

F>M

40-60

wrist

desmin variable

myxoid neurofibroma

F=M

20-30

extremities

myxoma

pointed serpentine nuclei

myxoid Schwannoma

F=M

20-30

head & neck, upper extremities

myxoid neurothekeoma

Antoni B areas,
S-100 variable

myxoid chondroma

F=M

30-60

hands, feet

myxoid chondrosarcoma

nodular,
hyaluronidase-resistant mucin, S-100 positive

superficial acral fibromyxoma

1:2

14-72

hands, feet

see differential

periungual, myxocollagenous, CD 34 positive

Malignant lesions

ossifying fibromyxoid tumour

F<M

40-60

distal extremities

multinodular,
nested epithelioid cells,
sheath of lamellar bone

myxoid dermatofibrosarcoma protuberans

F<M

40-60

lower extremities, groin

irregular outline,
storiform CD 34 variable

aggressive angiomyxoma

F>M

20-50

genital, perianal, pelvic area

angiomyofibroblastoma

hyaline vessels, some with thick walls, of variable size,
desmin and SMA variable

myxofibrosarcoma

F<M

50-80

lower extremity

multinodular,
bizarre hyperchromatic giant cells,
curvilinear vessels

low grade fibromyxoid sarcoma

F<M

20-40

extremities, retroperitoneum

alternating fibrous and myxoid areas,
whorled pattern

myxoid liposarcoma

F<M

40-60

extremities, retroperitoneum

plexiform capillaries,
perivascular lipoblasts

myxoid leiomyosarcoma

F=M

50-80

thigh, retroperitoneum

blunt-ended nuclei,
desmin and SMA positive

botryoid rhabdomyosarcoma

F<M

0-10

head & neck

oedematous, grape-like,
cambium layer,
rhabdomyoblasts,
myoglobin positive

extraskeletal myxoid chondrosarcoma

1:2

>35

lower extremity, juxtra-articular

strands of chondroblasts, S-100 positive

myxoid malignant melanoma

F=M

30-60

trunk>limbs

MFH, myxoid rhabdomyosarcoma, myxoid chondrosarcoma

variably positive for S-100 and HMB-45