Metastatic malignant pleural mesothelioma to the breast.

Abstract: A 51-year-old woman suffered from dyspnea for several days before she came to an outside clinic for help. Pleura biopsy was performed and the histologic diagnosis was malignant mesothelioma.

Sixteen months later, a palpable left breast lump was noted. Physical examination revealed a firm mass in the breast, measuring about 4 X 3.5 cm in size. Breast sonography showed a hypoechoic mass about 3 X 2 X 1.5 cm in size with irregular border in the middle part of the left breast. A mammogram revealed a speculated mass. Chest computed tomography was also performed, which revealed a large pleural mesothelioma and an irregular breast lesion.

Incisional biopsy of the left breast lump was performed and histologic examination revealed an infiltrative growth of neoplastic polygonal cells bearing hyperchromatic and pleomorphic nuclei and a small amount of pale, pinkish cytoplasm. Further immunohistochemical study was performed and the tumor cells were positive for low and high molecular weight cytokeratin, thrombomodulin and focally positive for CEA. The final histologic diagnosis was metastatic malignant mesothelioma.

Key Words: breast, metastasis, mesothelioma, pleura

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Secondary malignancy metastatic to the breast is uncommon with an incidence of 0.5 to 3% of patients with extramammary malignancy. (1,2) Most studies report an association with lymphoma, leukemia, and melanoma, followed by lung carcinoma. (3) Other malignancies including ovary, prostate, and stomach have been reported in several patients with breast metastasis. (1,2) Although mesothelioma is an uncommon tumor, its incidence is increasing. The rate of distant metastases from malignant mesothelioma has been reported to be as high as 25 to 33% in clinical series (4,5) and even higher in autopsy series. (6,7) Nevertheless, there is no known case of malignant pleural mesothelioma with metastases to the breast. To our knowledge, this is the first case of malignant pleural mesothelioma with metastases to the breast.

Case Report

A 51-year-old woman suffered from dyspnea for several days before she came to an outside clinic for help. Chest computed tomography was arranged and revealed nodular thickening of pleura of the left lung. Pleural biopsy was performed and the histologic diagnosis was malignant mesothelioma.

Sixteen months later, she came to the hospital with the chief complaint of a palpable left breast lump. Physical examination revealed a firm mass in the breast, measuring about 4 X 3.5 cm in size. Breast sonography showed a hypoechoic mass about 3 X 2 X 1.5 cm in size with irregular border in the middle part of the left breast (arrows, Fig. 1). Mammogram revealed a spiculated mass (arrows, Fig. 2). Due to the previous history of malignant pleural mesothelioma, chest computed tomography was also performed and revealed a large pleural mesothelioma (Fig. 3, open arrow) and an irregular breast lesion (Fig. 3, arrow).

Incisional biopsy of the left breast lump was performed and histologic examination revealed infiltrative growth of neoplastic polygonal cells bearing hyperchromatic and pleomorphic nuclei and a small amount of pale, pinkish cytoplasm (Fig. 4). Further immunohistochemical study was performed and the tumor cells were positive for low and high molecular weight cytokeratin, thrombomodulin, calretinin, WT-1, and focally positive for CEA. The final histologic diagnosis was metastatic malignant mesothelioma.

Comments

Malignant mesothelioma is a relatively rare tumor of mesodermal origin which arises in the pleural, pericardial or peritoneal cavity. In patients with malignant pleural mesothelioma, the most common presenting symptoms are chest pain and dyspnea, and a pleural effusion frequently develops. The reported case initially presented with the classic symptoms. Later, an ipsilateral palpable breast lump was noted. After image studies, breast malignancy was suspected and an incisional biopsy proved it to be metastatic malignant mesothelioma.

Mammography has been useful in the differential diagnosis of primary and metastatic breast malignancy. The typical mammographic presentation of metastatic breast malignancy is a round and dense mass. (8) Microcalcifications and spiculation are usually not present, except in rare cases of metastasis from ovarian carcinoma, and neither architectural distortion nor thickening of the skin is present. (8,9) Because the metastatic breast lesion usually evokes minimal proliferation of fibrous tissue surrounding the lesion, it is about the same size on palpitation and mammography. In contrast, the palpable mass of primary breast carcinoma is frequently larger than the mammographic size. (9) Surprisingly, mammogram of the reported case revealed a spiculated mass (arrows, Fig. 2) and breast sonography showed a hypoechoic mass about 3 X 2 X 1.5 cm in size with irregular border in the middle part of the left breast (arrows, Fig. 1). To the best of our knowledge, such unique image findings of metastatic malignant mesothelioma to the breast have never been reported. Such image presentations can probably be attributed to the more invasive character of metastatic malignant mesothelioma with much more proliferation of fibrous tissue surrounding the lesion. Hence, it should be very prudent to interpret the breast image findings in patients with known previous malignancy.

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Due to the previous history of malignant pleural mesothelioma, we performed incisional biopsy first and an unnecessary mastectomy was avoided. Fine needle aspiration cytology has been used to successfully identify both primary and metastatic malignancy in the breast and can be another preferred option for a differential diagnosis. (10)

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Secondary malignancy metastatic to the breast is uncommon, yet this entity does exist. The image findings of metastatic malignant pleural mesothelioma to the breast are somewhat different from those presenting in most of the metastatic lesions. Incisional biopsy or needle biopsy can be useful in making the differential diagnosis. In view of therapeutic implication, metastatic breast lesions should not be mistaken as the primary breast carcinoma. Only with the awareness of such possibility can prompt diagnosis and optimal treatment be achieved.

References

1. Paulus DD, Lidshitz HI. Metastasis to the breast. Radio Clin North Am 1982;20:561-568.

2. Toombs BD, Kalisher L. Metastatic disease to the breast: clinical, pathological and radiographic features. Am J Roentgenol 1977;129:673-676.

3. Vergier B, Trojani M, de Mascarel I, et al. Metastases to the breast: differential diagnosis from primary breast carcinoma. J Surg Oncol 1991;48:112-116.

4. Law MR, Hodson ME, Turner-Warwick M. Malignant mesothelioma of the pleura: clinical aspects and symptomatic treatment. Eur J Respir Dis 1984;65:162-168.

5. Solomons K. Malignant mesothelioma-clinical and epidemiological features: a report of 80 cases. S Afr Med J 1984;66:407-412.

6. Roberts GH. Distant visceral metastases in pleural mesothelioma. Br J Dis Chest 1976;70:246-250.

7. Huncharek M, Muscat J. Metastases in diffuse pleural mesothelioma: influence of histological type. Thorax 1987;42:897-898.

8. Chaignaud B, Hall TJ, Power C, et al. Diagnosis and natural history of extramammary tumors metastatic to the breast. J Am Coll Surg 1994;179:49-53.

9. Bohman LG, Bassett LW, Gold RH, et al. Breast metastases from extramammary malignancies. Radiology 1982;144:309-312.

10. Wakey PE Jr, Powers CN, Frable WJ. Metachronous soft-tissue masses in children and young adults with cancer: correlation of histology and aspiration cytology. Hum Pathol 1990;21:669-677.

Time is the longest distance between two places.
--Tennessee Williams

Shyr-Ming Sheen-Chen, MD, Yei-Wei Liu, MD, Hock-Liew Eng, MD, Chao-Cheng Huang, MD, and Sheung-Fat Ko, MD

From the Departments of Surgery, Pathology, and Diagnostic Radiology, Chang Gung Memorial Hospital, Kaohsiung; College of Medicine, Chang Gung University, Taiwan.

Reprint requests to Shyr-Ming Sheen-Chen, MD, Professor of Surgery, Department of Surgery, Chang Gung Memorial Hospital, Kaohsiung, 123, Ta-Pei Road, Niao-Sung Hsiang, Kaohsiung Hsien, Taiwan. Email: [e-mail]

Accepted April 5, 2006.

RELATED ARTICLE: Key Points

* Secondary malignancy metastatic to the breast is uncommon, yet this entity does exist.

* The image findings of metastatic malignant pleural mesothelioma to breast are somewhat different from those presenting in most of the metastatic lesions.

* In view of therapeutic implication, metastatic breast lesion should not be mistaken as the primary breast carcinoma.