LETTER TO THE EDITOR
To the Editor:
I have read with much interest the article by Redroban and Montalvo 1 reporting a myxoid liposarcoma of the vulva.
As already stated by the authors, vulvar myxoid liposarcomas are extremely rare and must be distinguished from the broad list of more common benign and malignant myxoid soft-tissue neoplasms of the vulva. When reviewing the microscopical description and the histologic pictures of the present case, a benign lipoblastoma-like tumor of the vulva can still be a major differential diagnosis 2,3. Similar to myxoid liposarcomas, lipoblastoma-like tumors of the vulva are grossly well circumscribed, multinodular, and gelatinous. Microscopically, lipoblastoma-like tumors of the vulva are composed of small ovoid cells and univacuolated lipoblasts in a myxoid background with prominent chicken-wire branching vessels, extremely mimicking a myxoid liposarcoma. Unlike lipoblastoma-like tumors of the vulva, myxoid liposarcomas lack a striking lobulation, and the lipoblasts in myxoid liposarcoma tend to cluster at the periphery of the lesion or around vessels, features that were not reported in the manuscript of Redroban and Montalvo. Therefore, in my opinion, molecular confirmation of the diagnostic DDIT3 (CHOP) gene rearrangement by fluorescence in situ hybridization is mandatory in this case. Recently, Mirkovic and Fletcher 3 described loss of Rb expression by immunohistochemistry in most of the lipoblastoma-like tumors of the vulva. However, Rb expression is intact in the histologic mimics of lipoblastoma-like tumor of the vulva, including the myxoid liposarcoma, and therefore could be an additional diagnostic marker in differentiating myxoid liposarcoma from lipoblastoma-like tumor of the vulva.
David Creytens, M.D., Ph.D.
Department of Pathology, Ghent University and Ghent University Hospital, Ghent, Belgium
1. Redroban L, Montalvo N. Vulvar myxoid liposarcoma, an extremely rare diagnosis: a case report and review of literature. Int J Gynecol Pathol 2019;38:17–20.
2. Lae ME, Pereira PF, Keeney GL, et al. Lipoblastoma-like tumour of the vulva: report of three cases of a distinctive mesenchymal neoplasm of adipocytic differentiation. Histopathology 2002;40:505–9.
3. Mirkovic J, Fletcher CDM. Lipoblastoma-like tumor of the vulva: further characterization in 8 new cases. Am J Surg Pathol 2015;39:1290–5.