Combined Papillated Bowen Disease and Clear Cell Atypical Fibroxanthoma

Clear cell variant of atypical fibroxanthoma and pleomorphic dermal sarcoma: molecular characterization and review of the literature

Atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) are unusual cutaneous tumors that typically arise in sun-damaged skin of elderly individuals. Several histopathologic variants have been described, but the clear cell variant is particularly rare with only 18 cases of AFX and 1 case of PDS reported. Here, we present two cases of clear cell AFX and PDS highlighting key histopathologic findings and molecular alterations assessed by next generation sequencing (NGS).

Lobulated Bowen's Disease with a Clear Cell Change

Bowen's disease usually manifests as a slowly enlarging erythematous scaly patch or plaque. An uncommon variant of Bowen's disease showing a verrucous appearance has been reported and a distinct variant with a prominent clear cell change on histopathology, in addition to a verrucous surface change, was also reported. We describe novel form of Bowen's disease having a cerebriform appearance and showing histopathologically a significant clear cell change and propose that the clinical term "lobulated Bowen's disease" would be compatible for the description of this unique clinical variant. From a histopathological point of view, the precise definition and etiopathogenesis of the clear cell change in Bowen's disease should be elucidated.

Primary dermal pleomorphic liposarcoma: utility of adipophilin and MDM2/CDK4 immunostainings

Liposarcoma, usually arises in deep soft tissues and pleomorphic liposarcoma (PL), is the rarest histopathologic variant. However, 15 cases of entirely dermal PL have been reported. We describe a case of a 79-year-old man who developed a rapidly growing nodule on his thorax. Excisional biopsy was performed and immunohistochemical studies were carried. The lesion was a well-circumscribed dermal nodule composed of multivacuolated pleomorphic lipoblasts and atypical mitotic figures. Neoplastic cells expressed CD10 and resulted negative S100 protein, Melan-A, MITF-1, AE1/AE3, CD4, CD68 (PGM1), retinoblastoma gene family protein, pericentrine and lysozyme. Adipophilin stain showed the lipid contents in the cytoplasm of the neoplastic cells. MDM2 and CDK4 resulted both negative. A diagnosis of primary dermal PL was made. This case shows the utility of adipophilin immunostaining to prove the lipid contents in neoplastic cells, which has the advantage of using formalin-fixed paraffin-embedded tissue and making needless frozen sections and ultrastructural studies to show these findings. Negative MDM2/CDK4 staining in our case argues against the possibility of dedifferentiated liposarcoma and further supports the diagnosis of true PL.

Clear cell atypical fibroxantoma: a rare variant of atypical fibroxanthoma and review of the literature

Atypical fibroxanthoma (AFX) is a superficial variant of pleomorphic malignant fibrous histiocytoma. Clear cell atypical fibroxanthoma (CCAFXA) is a rare variant of atypical fibroxanthoma. A 74-year-old male patient presented with a rapidly growing nodule on the shoulder, which had appeared over a 5-months period. Lesion was excised by the plastic surgeon. Microscopic examination showed an ulcerated nodule composed of pleomorphic spindled and polygonal cells with clear or vacuolated cytoplasm. The neoplastic cells were stained positively with CD68 and CD10 and were stained negative with S-100, Melan A, muscle-specific actin, or pan-cytokeratin. Final diagnosis was clear cell atypical fibroxanthoma. CCAFXA should be differentiated from other clear-cell neoplasms of the skin. Best of our knowledge only 11 cases CCAFXA of have been reported in published studies till date. Herein, we reported 12th case in literature of CCAFXA and review of the literature.