Malignant Mesothelioma With CD30-Positivity.

A Case Report and Review of the Literature

An immunoglobulin G1 antibody, Ber-H2 belongs to the CD30 cluster and reacts with a 105- to 120- kd membrane-bound glycoprotein.[1,2] The CD30 antigen is an activation marker not found on resting B cells, T cells, or monocytes. Ber-H2 positivity may be seen in the following types of cells in normal or reactive conditions: cells at the margin of germinal centers and around lymphoid follicles in reactive lymph nodes and tonsils, immunoblast-like cells in B-cell and T-cell zones, plasma cells, a few medullary thymocytes, rare cells in extranodal lymphoid tissue and bone marrow cells, including mature neutrophils, normoblasts, and erythrocytes, as well as pancreatic acini, neurons from the cerebral cortex, and Purkinje cells.[1-3]

Ber-H2 positivity can be seen in lymphomatous and nonhematopoietic tumors. Ber-H2 reacts with approximately 95% of cases of anaplastic large cell lymphoma (ALCL) and Reed-Sternberg cells and variants in about 90% of cases of nodular sclerosis, mixed cellularity, and lymphocyte-depleted Hodgkin lymphoma.[1,4-9] However, Ber-H2 reacts with Reed-Sternberg cells in only about 5% of cases of nodular lymphocyte predominance Hodgkin lymphoma.[10] Ber-H2 positivity may also be seen in other types of B-cell and T-cell non-Hodgkin lymphoma and plasma cell dyscrasias. The majority of the non-Hodgkin lymphoma are of large cell or immunoblastic morphology but also include one third of small noncleaved cell lymphomas.[1,5,10-15] A small percentage of nonhematopoietic tumors may be Ber-H2 positive, including pancreatic carcinomas, salivary gland tumors, and embryonal carcinomas.[16] Ber-H2 positivity in malignant mesothelioma has not previously been described and is the purpose of this case report.

REPORT OF A CASE

The patient was a 65-year-old man presenting with a 2-month history of worsening right-sided chest pain. Pertinent history included previous asbestos and toxic chemical exposures as well as a 25-year smoking history. Chest x-ray examination and a computed tomographic (CT) scan of the chest revealed 2 elliptical soft tissue masses (right posterior hemithorax, pleural based [Figure 1] and right medial pleural reflection [Figure 2]), the larger measuring 2.0 x 4.0 cm in greatest dimensions. A CT-guided needle biopsy specimen from the larger mass (right posterior hemithorax) was considered insufficient for diagnosis. Thus, the patient underwent a right thoracotomy and resection of a pleural mass. During thoracotomy, numerous pleural-based masses were noted. A frozen-section diagnosis rendered during the thoracotomy was "tumor; probable lymphoma, small cell; rule out oat cell carcinoma." Thus, a portion of the specimen was submitted to our institution for flow cytometric immunophenotyping; a portion was also received in formalin for routine histologic examination.

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MATERIALS AND METHODS

Cytology/Flow Cytometry

Fresh tissue designated "lung mass" was submitted for flow cytometric analysis with a diagnosis of "rule out lymphoma." Touch preparations of the lung mass were Wright stained. A single cell suspension of the tissue was prepared in RPMI medium (Cellgro Mediatech Tissue Culture Media, Fisher Scientific, Pittsburgh, Pa) and analyzed for various antigens on an Ortho Cytoron absolute flow cytometer (Ortho Diagnostic Systems, Raritan, NJ) using standard techniques and the following monoclonal antibodies: CD3, CD20, and CD45 (Becton-Dickinson, San Jose, Calif); CD4, CD5, CD10, and HLA-DR (Ortho); CD14 and CD19 (Coulter Clone, Coulter Immunology, Hialeah, Fla); and CD23, [Kappa] and [Lambda] (Dako Corporation, Carpinteria, Calif). Dual staining of antibodies was performed as follows: CD3/4, 19/5, 20/HLA-DR, 45/10, 14/23, and [Kappa]/[Lambda].

Histology/Immunohistochemistry

Also received with the fresh tissue was a formalin-filled container with a portion of the lung mass. A portion of this specimen was postfixed in B-5 fixative. Subsequently, the formalin-fixed and B-5-fixed tissue were routinely processed for sectioning and staining with hematoxylin-eosin (HE). The B-5 tissue was also stained with the following special and immunoperoxidase stains: periodic acid-schiff (PAS) with diastase; alcian blue with and without hyaluronidase; LCA (CD45), L26 (CD20), CD3, KP-1 (CD68), [Kappa], vimentin, HMB-45, cytokeratin, epithelial membrane antigen (EMA), and carcinoembryonic antigen (CEA, polyclonal) (Dako); Ber-H2 (CD30) (Nova Castra, Vector Laboratories, Burlingame, Calif); Leu-M1 (CD15) (Becton-Dickinson); [Lambda], S100, and B72.3 (BioGenex, San Ramon, Calif); and calretinin (Zymed, San Francisco, Calif). The PAS with diastase stain was performed following the McManus method, and the alcian blue with and without hyalurondiase stains were performed following the method described by Carson.

RESULTS

Cytology/Flow Cytometry

Cytomorphologic examination of the Wright-stained touch preparations of the lung mass revealed numerous clusters of acellular connective tissue with rare hematopoietic elements, including small lymphocytes, histiocytes, and plasma cells. Flow cytometric analysis of the suspension prepared from the lung mass revealed 23% of cells within the lymphocyte region, 8% within the monocyte (large cell) region, and 69% within the granulocyte region. Cells within the lymphocyte region were composed of approximately 77% T cells and 17% B cells with polyclonal surface light-chain expression. Cells within the large cell region failed to reveal an aberrant T-cell or monoclonal B-cell population.

Histology/Immunohistology

The HE-stained sections of the formalin-fixed and B-5-fixed lung mass tissue revealed fragments of dense fibrous connective tissue, consistent with pleura; lung parenchyma was not identified. The connective tissue was infiltrated by clusters and sheets of large malignant cells with irregular nuclear membranes, vesicular chromatin, prominent nucleoli, and abundant eosinophilic cytoplasm associated with a brisk mitotic rate (Figure 3). In areas, the malignant cells had a spindled appearance. In other areas were large zones of tumor necrosis with residual aggregates of malignant cells surrounding occasional small blood vessels. There was a mixed inflammatory infiltrate at the periphery of the tumor consisting predominantly of small lymphocytes, histiocytes, and plasma cells.

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The malignant cells stained intensely with cytokeratin (cytoplasmic), EMA (cytoplasmic and membrane), calretinin (cytoplasmic) (Figure 4), and Ber-H2 (cytoplasmic) (Figure 5) and were not immunoreactive with LCA, L26, CD3, KP-1, Leu-M1, [Kappa], [Lambda], vimentin, S100, HMB-45, B72.3, or CEA. They did not stain with PAS with diastase or with alcian blue with and without hyaluronidase.

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COMMENT

We report a case of a malignant mesothelioma originally submitted by the referring pathologist for flow cytometric immunophenotyping to exclude a malignant lymphoma. Flow cytometric immunophenotyping did not reveal an aberrant T-cell or monoclonal B-cell population. Subsequent histologic review with appropriate immunohistochemical stains established the diagnosis.

The diagnosis of malignant mesothelioma was supported by the intense reactivity of the malignant cells with cytokeratin, EMA, and calretinin. Negativity of the malignant cells with PAS with diastase, alcian blue with and without hyaluronidase, CEA, B72.3, and Leu-M1 excluded a diagnosis of adenocarcinoma.

Of interest, Ber-H2 was intensely present within the cytoplasm of the malignant cells. To our knowledge, Ber-H2 positivity has not previously been described in malignant mesothelioma and is the purpose of the case report. Anaplastic [CD30.sup.+] large cell lymphoma may have a varied histologic growth pattern with cohesive malignant cells, and the present finding expands the differential diagnosis of a CD[30.sup.+] cohesive large cell malignancy.

References

[1.] Schwarting R, Gerdes J, Durkop H, Falini B, Pileri S, Stein H. Bet-H2: a new anti-Ki-1 (CD30) monoclonal antibody directed at a formol-resistant epitope. Blood. 1989;74:1678-1689.

[2.] Schwarting R, Stein H. Cluster report: CD30. In: Knapp W, Dorken B, Gilks WR, et al, eds. Leucocyte Typing IV: White Cell Differentiation Antigens. New York, NY: Oxford University Press; 1989:419-422.

[3.] Van der Valk P, Mullink H, Huijgens PC, Tadema TM, Vos W, Meijer CJLM. Immunohistochemistry in bone marrow diagnosis: value of a panel of monoclonal antibodies on routinely processed bone marrow biopsies. Am J Surg Pathol. 1989; 13:97-106.

[4.] Leoncini L, Del Vecchio MT, Kraft R, et al. Hodgkin's disease and CD30-positive anaplastic large cell lymphomas--a continuous spectrum of malignant disorders: a quantitative morphometric and immunohistologic study. Am J Pathol. 1990;137:1047-1057.

[5.] Hall PA, D'Ardenne AJ, Stansfeld AG. Paraffin section immunohistochemistry, II: Hodgkin's disease and large cell anaplastic (Ki-1) lymphoma. Histopathology. 1988;13:161-169.

[6.] Casey TT, Olsen SJ, Cousar JB, Collins RD. Immunophenotypes of Reed-Sternberg cells: a study of 19 cases of Hodgkin's disease in plastic-embedded sections. Blood 1989;74:2624-2628.

[7.] DeMascarel I, Trojani M, Eghbali H, Coindre JM, Bonichon F. Prognostic value of phenotyping by Bet-H2, Leu-M1, EMA in Hodgkin's disease. Arch Pathol Lab Med. 1990;114:953-955.

[8.] Delsol G, Al Saati T, Gatter KC, et al. Coexpression of epithelial membrane antigen (EMA), Ki-1, and interleukin-2 receptor by anaplastic large cell lymphomas: diagnostic value in so-called malignant histiocytes. Am J Pathol. 1988;130: 59-70.

[9.] Greer JP, Kinney MC, Collins RD, et al. Clinical features of 31 patients with Ki-1 anaplastic large cell lymphoma. J Clin Oncol. 1991;9:539-547.

[10.] Chittal SM, Caveriviere P, Schwarting P, et al. Monoclonal antibodies in the diagnosis of Hodgkin's disease: the search for a rational panel. Am J Surg Pathol. 1988;12:9-21.

[11.] Hall PA, D'Ardenne AJ, Stansfeld AG. Paraffin section immunohistochemistry, I: non-Hodgkin's lymphoma. Histopathology. 1988;13:149-160.

[12.] Norton AJ, Isaacson PG. Detailed phenotypic analysis of B-cell lymphoma using a panel of antibodies reactive in routinely fixed wax-embedded tissue. Am J Pathol. 1987;128:225-240.

[13.] Hauschild A, Sterry W. Formalin-resistant leukocyte surface antigens in the diagnosis of cutaneous malignant lymphomas. Am J Pathol. 1989;135:177-184.

[14.] Piris M, Brown D, Gatter K, Mason D. CD30 expression in non-Hodgkin's lymphoma. Histopathology. 1990;17:211-218.

[15.] Piris M, Gatter K, Mason D. CD30 expression in follicular lymphoma. Histopathology. 1990;18:25-29.

[16.] Pallesen G, Hamilton-Dutoit SJ. Ki-1 (CD30) antigen is regularly expressed by tumor cells of embryonal carcinoma. Am J Pathol. 1988;133:446-450.

[17.] Carson, F. Histotechnology, a Self Instructional Text. Chicago, Ill: ASCP Press; 1990:122-129.

Accepted for publication November 17, 1999.

From the Division of Hematopathology, Department of Pathology, Saint Louis University Health Sciences Center St Louis, Mo.

Reprints: Cherie H. Dunphy, MD, Department of Pathology, Saint Louis University School of Medicine, 1402 Grand, St Louis, MO 63104.