ODONTOGENIC MYXOMA/ ODONTOGENIC FIBROMYXOMA
Histopathology:
- Low /hypocellular cellular tumor with prominent myxoid changes
- fibrous spindle and stellate cells are seen in myxoid and fibrous stroma, infiltrates in between bony trabeculae
- cells show pale eosinophilic cytoplasm
- minimal atypia and scanty to few mitoses are allowed
- collagen fibers are seen
- some epithelial rests are seen
- NO chondroid tissue
Points of Pathoclinics:
- Radiologically, odontogenic myxoma is uni/multi-locular lytic lesion, soap-bubble looking appearance resembling the ameloblastoma
- Always search for chondroid tissue, to rule out the possibility of chondromyxoid fibroma or osteochondromyxoma
- S-100 should be done to rule out myoxid rich neural tumors
- Infiltrative (in between bony trabeculae) and multilocular lesion has high probability of recurrence.
- low grade tumor, recurrence occurs if inadequately excised
- Curettage for odontogenic myxoma showed the highest recurrence rate, while marginal resection and segmental resection showed the lowest recurrence. Enucleation + peripheral osteotomy showed better results than enucleation or enucleation + curettage.
Reference:
Chrcanovic BR, Gomez RS. Odontogenic myxoma: An updated analysis of 1,692 cases reported in the literature. Oral Dis. 2019 Apr;25(3):676-683. doi: 10.1111/odi.12875. Epub 2018 Jun 8. PMID: 29683236.
Li TJ, Sun LS, Luo HY. Odontogenic myxoma: a clinicopathologic study of 25 cases. Arch Pathol Lab Med. 2006 Dec;130(12):1799-806. doi: 10.1043/1543-2165(2006)130[1799:OMACSO]2.0.CO;2. PMID: 17149953.