Myxoid lesions

Myxoid lesions occasionally appear on the pathologist's desk. The differential diagnosis is very large, as many lesions have a myxoid variant.

Short list

Myxoid stroma

Features:

• Stroma has a pale/blue appearance.

Gastrointestinal pathology

• Inflammatory fibroid polyp.

Gynecologic pathology

• Myxoid liposarcoma.

Soft tissue pathology

• Low-grade fibromyxoid sarcoma.
• Myxoid liposarcoma.
• Spindle cell lipoma.
• Extraskeletal myxoid chondrosarcoma.
• Myxoid chondrosarcoma.
• Aggressive angiomyxoma.
• Myxoid malignant peripheral nerve sheath tumour.
• Myxoid desmoid fibromatosis.
• Intramuscular myxoma.

Dermatopathology

• Myxoma.
• Myxoid DFSP.
• Basal cell carcinoma.
• Myxoid neurofibroma.

Breast pathology

• Phyllodes tumour.
• Fibroadenoma.
• Myxoid fibroadenoma.

Kidney pathology

Renomedullary interstitial cell tumour.

Salivary gland pathology

• Pleomorphic adenoma.

Cardiac pathology

• Atrial myxoma.

Neuropathology

• Pilomyxoid astrocytoma.
• Myxopapillary ependymoma.
• Chordoma.
• Chordoid meningioma.

Chondromyxoid stroma

Features:

• Cells in pseudonests.
• Surrounding stroma bluish.

Salivary gland pathology

• Pleomorphic adenoma.

Dermatopathology

• Chondroid syringoma.

An exhaustive differential diagnosis for myxoid lesions

Adapted from Miller with modifications:

Tumour	Group	Notes/comments
Perineurioma	other
Spindle cell squamous carcinoma	carcinoma
Myxoid pleomorphic undifferentiated sarcoma	sarcoma	myxoid MFH
Myxoid liposarcoma	sarcoma
Lipoblastoma	other
Myxoid chondrosarcoma	sarcoma
Chordoma	other
Myxoid leiomyoma	mesenchymal lesion
Myxoid leiomyosarcoma	sarcoma
Myxoid GIST	mesenchymal lesion
Myxoid solitary fibrous tumour	mesenchymal lesion
Myxoid omental-mesenteric hamartoma	other
Myxoid neurofibroma	other
Myxofibrosarcoma	sarcoma	some atypia, no swirling, vacuoles
Myxohyaline tumor of distal extremities	other
Myxoid dermatofibroma	other
Cutaneous myxoid cyst, cutaneous myxoma	other
Cardiac myxoma	other
Spindle cell lipoma	mesenchymal lesion	occasionally
Myxoma	other	brain-like appearance on CD34
Schwannoma	other
Metastatic myxoid carcinoma	carcinoma	GI, ovary, breast
Myxoid fibrosarcoma	sarcoma
Myxolipoma	mesenchymal lesion
Focal mucinosis	other
Appendiceal mucocele	other	Myxoglobulosis-like change
Mucocele of lip	other	Myxoglobulosis-like change
Mesenchymal hamartoma of liver	other	bile ducts in myxoid background
Angiomyxoma	other
Inflammatory myxohyaline tumor of distal extremities	other
Ossifying fibromyxoid tumor of soft parts	other
Myxoid osteosarcoma	sarcoma
Myxoinflammatory fibroblastic sarcoma	sarcoma
Myxopapillary ependymoma	other
Myxoid synovial sarcoma	other
Neurothekeoma	other	myxoid variant
Aggressive angiomyxoma	mesenchymal lesion
Angiomyofibroblastoma	mesenchymal lesion
Giant cell angiofibroma	mesenchymal lesion
Dermatofibrosarcoma protuberans	other
Embryonal rhabdomyosarcoma	sarcoma
Inflammatory myofibroblastic tumour	other
Cellular blue nevus	other
Superficial acral fibromyxoma	mesenchymal lesion
Intamuscular myxoma	mesenchymal lesion
Dermatofibroma	other
Nodular fasciitis	other

See also

• Long power list.