Atypical fibroxanthoma presenting in a patient with stage III mycosis fungoides

Collision Tumor Comprised of Atypical Fibroxanthoma and Invasive Squamous Cell Carcinoma: A Case Report of an Extremely Rare Entity

Single benign or neoplastic dermal lesions are very common. Lesions with two distinct tumors occurring as a single entity are extraordinary and known as collision tumors. In the present case, the lesion was diagnosed on biopsy, and later, wide local skin excision was performed. Excision revealed that the lesion was composed of two distinct cell populations exhibiting the characteristics of two separate neoplastic entities. The histopathology revealed a single lesion comprised of moderately differentiated squamous cell carcinoma that appeared to invade an atypical fibroxanthoma. This is unprecedented in the English literature and the first such case to be reported.

Atypical fibroxanthoma: new insights

Atypical fibroxanthoma (AFX) is an ultraviolet radiation-associated dermal neoplasm. To address the clinicopathologic and molecular features of this particular neoplasm. The author conducted a literature review using PubMed searching for articles relating to AFX. AFX usually appears as a rapidly growing nodular or nodulo-ulcerative lesion. It occurs on sun-exposed skin of elderly peoples. AFX may be composed predominantly of pleomorphic, spindle, epithelioid cells, or admixture of these cells. The differential diagnosis of AFX includes pleomorphic dermal sarcoma, squamous cell carcinoma, malignant melanoma and leiomyosarcoma. Several observations favor a mesenchymal origin for AFX. These reviews address the clinicopathologic features, molecular pathology, prognosis and treatment of this neoplasm.

Mycosis fungoides exhibiting features of a dermatofibroma: a case report and review of the literature

We present the case of a 60-year-old male with known stage IA mycosis fungoides (MF) who developed a suspicious tumor within a pre-existing lymphomatous plaque of the right forearm. Microscopy revealed an unusual mixed fibrohistiocytic proliferation as well as atypical intraepidermal and dermal lymphocytes. There was no evidence of large-cell transformation. Histopathological, immunohistochemical and clinical clues suggest this lesion might not have represented a dermatofibroma, but rather a hitherto unreported dermatofibroma-like process arising within a lesion of MF. The potential impact of this atypical lesion on the prognosis and clinical management of this patient highlights the importance of recognizing unusual clinical presentations of more common, benign lesions within this patient population.

Clinicopathologic analysis of primary atypical fibrous xanthoma of the esophagus

AIM: To explore the clinical and pathological features of primary atypical fibrous xanthoma of the esophagus, and to analyze its diagnosis, treatment and prognosis.

METHODS: One case of primary atypical fibrous xanthoma of the esophagus treated at Fuzhou General Hospital of Nanjing Military Command of Chinese PLA was analyzed in this study. The diagnosis, treatment and follow-up data as well as histopathological and immunohistochemistry data for the disease were analyzed to reveal the clinicopathologic characteristics of the disease.

RESULTS: The tumor was located under the squamous epithelium of the upper esophagus, with a clear boundary. Histopathological analysis showed that the tumor was composed of cells of spindle, polygonal and irregular shape, collagen fibers, and esophageal glands. The tumor cells consisted of mononuclear, binuclear and polynuclear giant cells that shared some similar morphological characteristics. Mononuclear, binuclear and polynuclear giant cells could be detected in the transitional area. Some areas revealed pathological mitosis (< 2/50 HPF). Immunohistochemistry analysis showed that the tumor cells were strongly positive for CD68, CD163, S-100, and vimentin, weakly positive for α-SMA, h-caldesmon, and Ki-67 (proliferation index: ~8%), but negative of CKpan, EMA, CK (L), CK (H), F8, CD34, CD117, Dog-1, actin, desmin, CD10, and CD99.

CONCLUSION: Primary atypical fibrous xanthoma of the esophagus is an extremely rare mesenchymal tumor with benign behavior and good prognosis. A differential diagnosis should be made among atypical fibrous xanthoma of the esophagus, esophageal sarcomatoid carcinoma, carcinoma-sarcoma, leiomyoma, gastrointestinal stromal tumor, and malignant fibrous histiocytoma.