Primary carcinosarcoma of the helix of the ear

Ear, Nose & Throat Journal, Nov, 2005 by Vladimir Vincek, Marjan Mirzabeigi, Brian S. Jewett, W. Jarrard Goodwin

Abstract

We report our histologic and immunohistochemical findings in a rare case of cutaneous carcinosarcoma involving the helix of the ear. The tumor exhibited cellular features of both basal cell and squamous cell carcinoma and a malignant mesenchymal component that was consistent with malignant fibrous histiocytoma. The epithelial component exhibited a positive immunohistochemical reaction to cytokeratin and a negative reaction to vimentin, whereas the mesenchymal component showed a positive immunohistochemical reaction to vimentin and a negative reaction to cytokeratin. To the best of our knowledge, this is only the third reported case of a carcinosarcoma of the ear and the second case in which it developed on the helix.

Introduction

Carcinosarcoma is a rare tumor in which both elements--the epithelial and mesenchymal components--are malignant. This tumor has been reported to occur at various sites, including the adrenal gland, colon, endometrium, lung, oral cavity, and prostate; at each of these sites, the cancer is associated with metastasis and a poor outcome.

Primary cutaneous involvement is extremely rare, as we found only 20 cases that were previously reported in the literature (table). (1-15) All of these cutaneous carcinosarcomas had developed in patients who were older than 40 years, and most of them behaved in a manner that was clinically less aggressive than the progression of carcinosarcomas at other sites. To the best of our knowledge, only 2 cases of carcinosarcoma of the ear (9,14) and 1 case of carcinosarcoma of the ear helix (14) have been previously reported. We report a new case of carcinosarcoma of the helix.

Case report

A 73-year-old man presented with an enlarging, semifirm, 3.5 x 2.5-cm lesion that had arisen on the helix of the left ear and extended into the concha (figure 1). The mass, which had begun to develop 1 year earlier, was minimally mobile, and the overlying skin was not ulcerated. The clinical picture suggested a squamous cell carcinoma, The patient denied any other significant medical problems. External examination and a clinical workup did not reveal any enlarged lymph nodes or distant metastasis.

[FIGURE 1 OMITTED]

Wide excision of the ear was performed. Intraoperatively, frozen sections were obtained in an effort to ensure negative surgical margins. Gross pathologic examination identified the mass as a 3.5 x 2.5 x 2.5-cm polypoid tumor. On cross-section analysis, the tumor was firm and 0.5 cm from the deep margin.

Microscopic examination revealed that the tumor had originated in squamous epithelium. Large aggregates of basaloid epithelium were consistent with the histology of a basal cell carcinoma (figure 2, A). The tumor also exhibited some degree of squamous differentiation that was suggestive of a squamous cell carcinoma (figure 2, B). Large cystic spaces, areas of hyalinization, and focal necrosis were identified. The tumor also exhibited peripheral palisading of nuclei, some ductal differentiation, and the presence of closely associated hyalinized stroma, suggesting focal sweat gland differentiation. Mitotic figures were easily observed throughout the tumor's epithelial component. A large portion of the tumor contained a highly pleomorphic spindle-cell stroma with numerous multinucleated and bizarre cells and numerous mitoses. Histologically, the tumor's mesenchymal component was most consistent with a malignant fibrous histiocytoma (figure 2, C).

[FIGURE 2 OMITTED]

On immunoperoxidase staining, the epithelial component was positive for cytokeratin and p63 and negative for vimentin and epithelial membrane antigen (EMA) (figure 3, A). The mesenchymal component was positive for vimentin and CD 10, focally positive for CD68 and factor XIII, and negative for cytokeratin, S-100, caldesmon, and smooth-muscle actin (figure 3, B). Both components demonstrated a high proliferation index with the Ki-67 proliferation marker. Based on the histomorphologic findings, we established a diagnosis of carcinosarcoma.

[FIGURE 3 OMITTED]

At the 6-month postoperative follow-up, the patient manifested no evidence of distant metastasis or recurrence.

Discussion

Cutaneous carcinosarcomais a biphasic malignant tumor made up of both epithelial and mesenchymal components, (2,5,6,11,13,14) Our review of the literature revealed a lack of consensus regarding terminology, as this entity is variously referred to as spindle-cell carcinoma, sarcomatoid carcinoma, metaplastic carcinoma, and pseudosarcoma. (14)

The prognosis for cutaneous carcinosarcoma appears to be better than the prognosis for its visceral counterparts. H In the 20 previously reported cases of cutaneous carcinosarcoma, metastasis developed in only 4 patients (table). (2,4,6,10) On the other hand, most patients with carcinosarcomas in other organs develop metastasis. (11) No distant metastasis or local recurrence occurred in the 2 previously reported cases of cutaneous carcinosarcoma of the external ear following complete local excision. (9,14)