CLINICAL HISTORY:

Signs and symptoms:  none

Previous Treatment:  none

Other information:  Past history of basal cell carcinoma. Patient returns for a follow up visit to be monitored for possible recurrence of Skin Cancer and to evaluate skin for the possible development of new pre-cancers. Patient did not know how long the spot on the right forehead had been there. The lesion is asymptomatic.

PHYSICAL EXAM:

Red, juicy, dome-shaped nodule that is ulcerated and telangiectatic. Size is 4mm located on right forehead. No cervical lymphadenopathy.

LABORATORY TESTS:

Shave biopsy was performed

DERMATOHISTOPATHOLOGY:

Hyperkeratosis and parakeratosis with proliferation of neoplastic squamous epithelial cells in an irregular pattern with little tendency towards keratinization and with surrounding fibrosis and inflammatory reaction. Immunoperoxidase stains were positive for CD68, a marker of fibrohistiocytic differentiation and negative for cytokeratin, S-100 protein, and HMB45 antigen.

*Slides and description taken from http://www.bweems.com/ with permission

DIFFERENTIAL DIAGNOSIS:

1.   Spindle cell squamous cell carcinoma
2.   Superficial portion of a malignant fibrous histiocytoma
3.   Atypical fibroxanthoma
4.   Desmoplastic malignant melonoma
5.   Leiomyosarcoma

SCROLL DOWN FOR ANSWER AND DISCUSSION.

CORRECT DIAGNOSIS:

Atypical fibroxanthoma

DISCUSSION:

Atypical fibroxanthoma is a tumor that occurs in older patients in the areas of sun exposure and/or therapeutic radiation. The lesions clinically are suggestive of malignancy because they are fast growing. This disease entity often leads to misdiagnosis and results in unnecessary and extensive surgery. It is a low-grade malignancy related to malignant fibrous histiocytoma. Because of atypical fibroxanthoma is small in size and more superficially located, it has much better prognosis than malignant fibrous histiocytoma. Some cases may represent primary squamous cell carcinoma (SCC) that fails to express keratin. The tumor is often presenting as a small, firm nodule with an eroded crusted surface.. Histologically, lesions show a highly atypical and pleomorphic cellular appearance. The tumor consists of spindle cells mingled with atypical histiocytes. Vesicular nuclei are located in some spindle cells. The cytoplasm maybe vacuolated and resemble the foamy cells of xanthomas.
They typically respond to simple excision but have a high rate of local recurrence. For this reason Mohs surgery is the treatment of choice. Factors important to consider are lesion location, patient age, histopathologic appearance, and the observation that the tumor arises from the dermis, not the fat. Metastasis is rare.

TREATMENT:

Actual treatment for this patient:
The lesion was excised with specimen sent to pathology for confirmation. The margins were cleared and patient was instructed to follow up for recheck in 3 months.

Other Treatment options:
Evidence is accumulating that demonstrates that Mohs micrographic surgery, with its high reliability of complete tumor removal and tissue-conserving property, may be the treatment of choice for atypical fibroxanthoma on certain areas of the head and neck.

REFERENCES:

1. Lee CS, Chou ST: p53 protein immunoreactivity in fibrohistiocytic tumors of the skin. Pathology 1998 Aug; 30(3): 272-5.

2. Leong AS, Milios J: Atypical fibroxanthoma of the skin: a clinicopathological and immunohistochemical study and a discussion of its histogenesis. Histopathology 1987 May; 11(5): 463-75.

3. Ma CK, Zarbo RJ, Gown AM: Immunohistochemical characterization of atypical fibroxanthoma and dermatofibrosarcoma protuberans. Am J Clin Pathol 1992 Apr; 97(4): 478-83.

4. Requena L, Sangueza OP, Sanchez Yus E, Furio V: Clear-cell atypical fibroxanthoma: an uncommon histopathologic variant of atypical fibroxanthoma. J Cutan Pathol 1997 Mar; 24(3): 176-82.

5. Silvis NG, Swanson PE, Manivel JC, et al: Spindle-cell and pleomorphic neoplasms of the skin. A clinicopathologic and immunohistochemical study of 30 cases, with emphasis on "atypical fibroxanthomas". Am J Dermatopathol 1988 Feb; 10(1): 9-19.

6. Starink TH, Hausman R, Van Delden L, Neering H: Atypical fibroxanthoma of the skin. Presentation of 5 cases and a review of the literature. Br J Dermatol 1977 Aug; 97(2): 167-77.

Additional Comment:

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