Pleomorphic dermal sarcoma: adverse histologic features predict aggressive behavior and allow distinction from atypical fibroxanthoma
The other tumors rarely seen were dermatofibroma, atypical fibroxanthoma
and Kaposi's sarcoma and actinic Keratosis.
The tumor showed a classic atypical fibroxanthoma made of a diffuse spindle cell dermal growth with marked cellular atypias, giant cells, and atypical mitoses (Fig.
However, the well-known polemic on the nature of atypical fibroxanthoma as a spindle-squamous cell carcinoma (SCC) should be remembered (20) because cases of cutaneous amyloidosis related to common SCC have been reported (5).
Atypical fibroxanthoma presents as a dermally based, circumscribed lesion with overlying epidermal collarette, central ulceration, and parakeratosis (Figure 1, A and B).
Atypical fibroxanthoma of the skin: aclinicopathologic study of 140 cases.
Atypical fibroxanthoma is a pleomorphic, superficial spindle cell tumor of low-grade malignancy that must be distinguished histologically from other atypical spindle cell tumors of the dermis.
Atypical fibroxanthoma and spindle cell SCCs fail to show SOX10 expression, but malignant peripheral nerve sheath tumors show scattered positivity similar to S100.
is thought to be a predominantly UV-induced tumor, although irradiation and immunosuppression, for example, in organ transplant patients, are also thought to play a role.
64) To differentiate spindle cell squamous cell carcinoma from other spindle cell neoplasms, such as atypical fibroxanthoma
, spindle cell melanoma, leiomyosarcoma, and others, investigators demonstrated that spindle cell squamous cell carcinoma expressed p63 strongly and diffusely, whereas most controls were negative or displayed weaker and more focal staining.
Both squamous cell carcinoma and atypical fibroxanthoma
arise on sun-damaged skin.
It has also been demonstrated recently in the majority of xanthomatous skin lesions, (8) atypical fibroxanthomas
, typical dermatofibromas, and occasional epithelioid dermatofibromas.