Carcinosarcoma of the Tongue With Cyclin D1 Gene Amplification.

Carcinosarcoma (spindle cell carcinoma, sarcomatoid carcinoma) of the tongue is a rare and aggressive malignancy.[1-3] Histologically, it is composed of carcinomatous and sarcomatous characteristics. The carcinomatous component is almost always squamous cell carcinoma, and the sarcomatous component usually contains a pleomorphic spindle cell proliferation. The sarcomatous component is considered a variant growth pattern of squamous cell carcinoma.[1-3]

Carcinosarcoma of the tongue showing a unique morphology is an interesting neoplasm, but its molecular aspects remain unknown. Recently, various abnormalities of the genes controlling cell cycle have been found in many types of human malignancy.[4] We previously showed that the cyclin D1 (CD1) gene, which is one of the cell-cycle regulator genes, was frequently amplified in esophageal carcinosarcoma.[5,6] Cyclin D1 gene amplification is thought to be an important oncogenic event in many types of tumors, including esophageal carcinosarcoma.[4-6] Because esophageal carcinosarcoma shows the same morphologic features as carcinosarcoma of the tongue, we examined whether the CD1 gene is amplified in carcinosarcoma of the tongue as well. Herein we present a case of carcinosarcoma of the tongue with CD1 gene amplification.

REPORT OF A CASE

A 51-year-old Japanese man presented to Kushiro Rosai Hospital (Kushiro, Japan) with a painless mass of the tongue. Physical examination revealed a

polypoid lesion at the right margin of the tongue. Following biopsy, the patient underwent surgical excision of the polypoid lesion. The patient remains well and has experienced no tumor recurrence in the 15 months since the surgery.

MATERIALS AND METHODS

Specimens were fixed in 4% formaldehyde and processed in paraffin. The slides were stained with hematoxylin-eosin. Immunohistochemistry was performed on 4-[micro]m-thick tissue sections using the streptavidin-biotin complex method (Histofine SAB-PO Kit, Nichirei Corporation, Tokyo, Japan). The slides were deparaffinized and stained using the following antibodies: vimentin (Dako Japan, Kyoto, Japan; monoclonal), cytokeratin (Dako Japan; monoclonal), AE1/AE3 (Dako Japan; monoclonal), and CD1 (Novocastra, Newcastle, United Kingdom; monoclonal). For fluorescence in situ hybridization (FISH), 4-[micro]m-thick tissue sections were cut from paraffin blocks. Fluorescence in situ hybridization was performed using a paraffin pretreatment reagent kit and probe mixture (Vysis, Inc, Downers Grove, Ill), according to the manufacturer's protocols as described previously.[6] Probes and the corresponding hybridization mixture (Vysis) included CD1 probe labeled with spectrum orange and chromosome enumeration probe 11 labeled with spectrum green. Nuclei were counterstained with 4',6-diamidino-2-phenylindole dihydrochloride II staining solution (Vysis). Analysis and photography of the FISH-labeled slides were performed using the CytoVision system (Applied Imaging Corporation, Santa Clara, Calif), following the manufacturer's protocol.

PATHOLOGIC FINDINGS

Macroscopic examination showed a polypoid tumor measuring 12 x 12 x 6 mm that originated from the right margin of the tongue (Figure 1). The surface of the tumor was ulcerated. Histologic examination revealed a biphasic tumor consisting of a spindle cell-type sarcomatous component and a squamous cell carcinoma (Figure 2). Although the bulk of the tumor mass consisted of the sarcomatous component, the infiltrative squamous cell carcinoma admixed within the sarcomatous component. The spindle-shaped cells were pleomorphic with ovoid nuclei of various sizes, and frequent mitotic figures also were observed. The tumor did not extend deeply enough to invade subjacent muscle.

[Figures 1-2 ILLUSTRATION OMITTED]

Immunohistochemically, the squamous cell carcinoma cells were positive for cytokeratin and AE1/AE3, whereas vimentin was not immunoreactive. The spindle-shaped cells of the sarcomatous component were positive for vimentin, whereas cytokeratin and AE1/AE3 were not immunoreactive.

Fluorescence in situ hybridization was performed as described previously[6] to determine CD1 gene amplification in the carcinosarcoma of the tongue. Interphase nuclei of both the carcinoma cells and the spindle-shaped sarcomatous cells showed more orange CD1 signals than green chromosome enumeration probe 11 signals by FISH analysis (Figure 3, A and B), demonstrating CD1 gene amplification. Cyclin D1 gene amplification was observed diffusely in both components, whereas no CD1 gene amplification was observed in the adjacent nonneoplastic tissue. Immunohistochemically, CD1 protein was also detected in both components (Figure 3, C and D).

[Figure 3 ILLUSTRATION OMITTED]

COMMENT

Carcinosarcoma (spindle cell carcinoma, sarcomatoid carcinoma) of the tongue is a rare and interesting neoplasm with unique morphologic features.[1-3] However, its molecular aspects are still unclear.

The histologic and immunohistochemical features of the tumor in the case presented here are compatible with carcinosarcoma of the tongue. Immunohistochemically, cytokeratin and AE1/AE3 were negative in the sarcomatous component of our case. Although the sarcomatous component is considered a variant growth pattern of squamous cell carcinoma, expression of cytokeratin by immunostaining appears to be variable.[1]

The tumor in the present case showed CD1 gene amplification in both the carcinomatous and sarcomatous components. Immunohistochemically, CD1 expression was positive in both components, suggesting that amplified CD1 gene could be expressed in carcinosarcoma. Cyclin D1, a cell-cycle regulator, binds to cyclin-dependent kinase 4 or 6, and inactivates the retinoblastoma protein so that cells can enter S phase.[7] Its overexpression, which arises through the amplification or rearrangement of the gene, is thought to be oncogenic.[4,7] Cyclin D1 gene amplification has been found in many types of human tumors, including head and neck squamous cell carcinoma.[4,8] Thus, our results suggest that CD1 gene amplification, at least in some cases, plays a role in the process of malignant transformation of carcinosarcoma of the tongue.

Tumors of this type also arise in the esophagus. We previously reported that the CD1 gene is frequently amplified in both the components of esophageal carcinosarcoma.[5,6] As esophageal carcinosarcoma has the same morphologic and immunohistochemical features as carcinosarcoma of the tongue, CD1 gene amplification may be a common important event in the molecular pathogenesis of tumors of this morphologic type.

The prognosis of carcinosarcoma of the head and neck is controversial.[1-3,9,10] Levinton and Evans[9] showed that its prognosis is closely related to the depth of invasion. On the other hand, Ellis and Corio[10] reported that no histomorphologic characteristic, including the depth of invasion, was a reliable prognostic indicator in carcinosarcoma of the oral cavity.

Recently, Nogueira et al[8] reported that CD1 gene amplification is associated with recurrence and/or metachronous tumors in head and neck squamous cell carcinoma, and Mineta et al[11] reported that CD1 overexpression correlates with poor prognosis in patients with tongue squamous cell carcinoma. The prognostic value of CD1 amplification and overexpression has not been studied in carcinosarcoma. A FISH and immunohistochemical study using paraffin-embedded specimens would make it possible to analyze accumulated cases. Additional studies of larger series of accumulated cases would be required to determine the prognostic value of CD1 amplification and overexpression, although carcinosarcoma is a rare tumor.

References

[1.] McClatchey KD, Zarbo RJ. Spindle-cell carcinoma. In: Sternberg SS, eds. Diagnostic Surgical Pathology. 3rd ed. New York, NY: Lippincott Williams & Wilkins; 1999:829-831.

[2.] Rosai J. Sarcomatoid carcinoma. In: Rosai J, eds. Ackerman's Surgical Pathology. 8th ed. St Louis, Mo: Mosby Year Book Inc; 1996:327.

[3.] Weinder N. Sarcomatoid carcinoma of the upper aerodigestive tract. Semin Diagn Pathol. 1987;4:157-168.

[4.] Peters G. The D-type cyclins and their role in tumorigenesis. J Cell Sci Suppl. 1994;18:89-96.

[5.] Suzuki H, Moriya J, Nakahata A, Fujioka Y, Inoue K, Nagashima K. Cyclin D1 gene amplification in esophageal carcinosarcoma shown by differential polymerase chain reaction. Hum Pathol. 1998;29:662-667.

[6.] Suzuki H, Fujioka Y, Nagashima K. Cyclin D1 gene amplification and p16 gene deletion in patients with esophageal carcinosarcoma. Diagn Mol Pathol. 1998;7:253-259.

[7.] Hunter T, Pines J. Cyclins and cancer, II: cyclin D and CDK inhibitors come of age. Cell. 1994;79:573-582.

[8.] Nogueira CP, Dolan RW, Gooey J, et al. Inactivation of p53 and amplification of cyclin D1 correlate with clinical outcome in head and neck cancer. Laryngoscope. 1998; 108:345-350.

[9.] Levinton GS, Evans HL. Sarcomatoid squamous cell carcinoma of the mucous membranes of the head and neck: a clinicopathologic study of 20 cases. Cancer. 1981 ;48:994-1003.

[10.] Ellis GL, Corio RL. Spindle cell carcinoma of the oral cavity: a clinicopathologic assessment of fifty-nine cases. Oral Surg. 1980;50:523-534.

[11.] Mineta H, Miura K, Takebayashi S, et al. Cyclin D1 overexpression correlates with poor prognosis in patients with tongue squamous cell carcinoma. Oral Oncol. 2000;36:194-198.

Accepted for publication August 4, 2000.

From the Departments of Pathology and Clinical Research (Drs Suzuki and Yamashiro), Sapporo National Hospital, Sapporo, Japan; the Departments of Otolaryngology (Dr Yoshida) and Pathology (Dr Suzuki), Kushiro Rosai Hospital, Kushiro, Japan; and the Department of Pathology, Kyorin University School of Medicine, Mitaka, Japan (Dr Fujioka).

Reprints: Hiroaki Suzuki, MD, Department of Clinical Research, Sapporo National Hospital, 4-2, Kikusui, Shiroishi-Ku, Sapporo 003-0804, Japan.

The authors thank K. Miyazawa (Hokkaido University Hospital, Hokkaido, Japan) for instruction on the CytoVision system.