2018 Volume 57 Issue 4 Pages 217-222
Background : Superficial CD34-positive fibroblastic tumors are a novel type of soft tissue tumors that are of intermediate malignancy grade. Herein, we report the cytologic features of this tumor arising in a young male and discuss the differential diagnosis of these tumors.
Case : An 18-year-old man presented with a subcutaneous mass in the right thigh that measured 9 cm in diameter, and underwent surgical resection. We prepared crush, touch imprint and liquid-based cytological smears from the resected tumor ; in all of these smears, numerous atypical cells were observed as single cells or in clusters in a background of fibrovascular stroma and chronic inflammatory cells. These atypical spindle-shaped cells had granular eosinophilic cytoplasm and pleomorphic nuclei, with the cells also occasionally showing intranuclear cytoplasmic pseudo-inclusions. The cell borders were indistinct, necrosis was absent, and there were few mitotic figures. Immunocytochemically, the atypical cells showed strongly positive staining for CD34. The diagnosis of the tumor was confirmed by histological examination.
Conclusion : Although the pleomorphic nuclei and occasional intranuclear cytoplasmic pseudo-inclusions in this tumor are reminiscent of high-grade malignancies, the lack of necrosis and low mitotic index underscore their differences from typical high-grade sarcomas. When considering the clinical features and CD34 positivity along with cytomorphological features, it may be able to suspect superficial CD34-positive fibroblastic tumors in the practice of cytology.
