Case Report

A Case of Histiocytic Sarcoma Arising from Mycosis Fungoides

Table 1

A comparison of the immunophenotypic, cytomorphologic, and clinical findings of HS and MF.

MalignancyHistiocytic sarcomaMycosis fungoides

ImmunophenotypeCD68CD4
CD163CD8
LysozymeCD56
May be variableCD4/8-CD30¥
CytomorphologyLarge and round oval nuclei with spindling; large, atypical pleomorphic lymphocytes with eosinophilic cytoplasmT cells in epidermis and dermis with ceribriform nuclei; Pautrier micro abscesses in epidermis
May be variable
Clinical findingsUnifocal to metastatic disease with systemic symptoms; preferentially involves skin, soft tissue, or the gastrointestinal tractCutaneous patches/plaques or tumors that may be localized or diffuse

¥CD30 (Ki-1) positivity may be seen in primary cutaneous anaplastic large-cell lymphoma, lymphomatoid papulosis, pagetoid reticulosis, and transformed MF.