Leu-M1-positive small cell carcinoma

A case of metastatic small cell carcinoma of the lung is reported; initially, on the basis of morphology, phenotyping with monoclonal antibodies, and cytochemistry, the carcinoma was interpreted as a hematopoietic neoplasm. Noncohesive blast-like cells observed in bone marrow and lymph node biopsy specimens stained with the monoclonal antibodies Leu-M1 and OKIa1 and were also positive for nonspecific esterase and acid phosphatase. Although these findings suggested a monocytic origin for the neoplastic cells, further analysis, including ultrastructural examination, disclosed metastatic small cell carcinoma. This case illustrates the need for caution in the interpretation of staining with monoclonal antibodies because of the potentially wide range of normal and abnormal cells and tissues that may react with monoclonal reagents.     

The phenotype of mantle zone lymphoma studied by monoclonal antibodies

The clinical, pathological and immunological features of a case of mantle zone lymphoma are described. The patient presented at the age of 16 with a history of painless enlargement of the inguinal lymph nodes, biopsy of which revealed a nodular small cell lymphoma. During the course of 11 yr he was treated with total nodal irradiation, splenectomy and combination chemotherapy at different times. A recent lymph node biopsy reviewed along with the previous node biopsies was diagnosed as mantle zone lymphoma. At this stage, the immunological studies showed that the neoplastic lymphoid cells had characteristic markers of mantle zone lymphocytes. He is asymptomatic with mild generalized lymphadenopathy 11 yr after the initial diagnosis. This case illustrates the diagnostic and therapeutic problems which may be encountered. Detailed immunological marker studies with an extended panel of monoclonal antibodies are described.     

Primary small cell (oat cell) carcinoma of the breast: report of a case and review of the literature

A case of primary small cell (oat cell) carcinoma of the breast in a 41-year-old woman is presented. The patient was alive and well without disease 16 months after modified radical mastectomy and subsequent chemotherapy. The tumor cells revealed morphologic similarity to oat cell carcinoma of the lung and immunohistochemical expression of neuroendocrine markers. In ultrastructural examination, the tumor cells had neurosecretory granules. Review of nine previously reported cases and this case of primary small cell carcinoma of the breast has revealed that this type of tumor shows prominent vascular invasion, frequent lymph node metastasis, infrequent expression of estrogen receptor, and also very poor prognosis. Immunohistochemical study for the c-kit proto-oncogene product, which has been reported to be a specific marker for pulmonary small cell carcinoma, demonstrated positive reactivity in approximately 80% of the tumor cells of this case, which is the first report according to our knowledge. The expression of c-kit might be some aid to the diagnosis of primary small cell carcinoma of the breast.     

Small cell (oat cell) carcinoma of the breast

A case of small cell (oat cell) carcinoma, which represents both the most dlstlnctlve and the least common type of mast carcinoma wtth neuroendocrine dlfterentiation and usually shows the most aggressive behavior, is described. Radlcal mastectomy was performed on a Wyearold female for a 10 cm tumor located in the outer part of the right breast with cutaneous ulceration Microscoplcally, the tumor predominantly consisted of a diffuse proliteration of small, round to ovoid cells with hyperchromatlc nuclei and ill-defined, scant cytoplasm that was reminiscent of oat cell carclnoma of the lung. There were foci of invasive ductal carcinoma and ductal carcinoma in situ . Small cell carcinoma areas constituted approximately 90% of the neoplasm. The patlent had axlllary lymph node metastasis. The small tumor cells were argyrophlllc and positive for CAM5.2, carclnoembryonic antigen, neuron-specific enolase, Leu-7, chromogranln A and synaptophysin. Flow cytometric analysis showed an aneuplold DNA content. The patient was alive and well without disease 4 years after surgery. Small cell carcinomas of the breast may exhibkt a spectrum of malignancy that is comparable to similar tumors at better known primary sites.     

Oat cell carcinoma of the gallbladder

Among 448 malignant epithelial tumors of the gallbladder, 19 were classified as oat cell carcinomas. Seventeen cases occurred in elderly women. Eighteen of the patients had cholelithiasis. The neoplasms were highly lethal, metastasizing early and causing death shortly after diagnosis. All 19 patients died as a direct result of the tumors, with liver, regional lymph node, and/or lung metastases. Combination chemotherapy produced objective responses in two patients, the longest survivors of the series (11 and 13 months). The salient morphologic features of oat cell carcinomas of the gallbladder include large size at the time of diagnosis, extensive necrosis, and propensity for submucosal growth. Histologically, these tumors are composed of variable proportions of two cell types, round and fusiform, arranged in solid sheets, cords, or festoons. In areas of necrosis, the deposition of DNA in vessel walls is seen occasionally. Four tumors contained neoplastic glands similar to those present in well-differentiated adenocarcinomas of the gallbladder. These tumors were considered to be a combined form of oat cell carcinoma. With the use of immunoperoxidase stains, focal carcinoembryonic antigen reactivity was demonstrated in three of 11 tumors. Electron microscopic examination revealed neurosecretory granules. Morphologically, these tumors resembled the oat cell carcinomas that occur at other sites.     

p53 expression in oat and non-oat small cell lung carcinomas: correlations with proliferating cell nuclear antigen.

AIMS--To investigate the immunohistochemical expression of p53 protein in small cell lung carcinoma (SCLC), comparing it with that in non-small cell carcinoma (NSCLC); and to evaluate the correlation between p53 and proliferating cell nuclear antigen (PCNA) expression as well as between p53 and PCNA expression and survival. METHODS--Paraffin wax embedded tissues from 61 cases of primary lung carcinoma were stained for p53 protein and PCNA using the monoclonal antibodies 1801 and PC-10, respectively, in a standard avidin-biotin immunoperoxidase method. RESULTS--Of the 61 lung carcinomas 35 (57%) were positive for p53 (range 1% to 90%). Ninety percent of the non-oat SCLC contained positive cells and the labelling index (LI) was significantly higher than that of the oat SCLC (p < 0.001). SLCC also displayed a higher p53 LI than NSCLC (p < 0.01); no difference was found between squamous carcinoma, adenocarcinoma, and oat cell carcinoma. A p53 LI of greater than 1% tended to be associated with nodal metastases (p < 0.05), and p53 expression in node positive tumours as well as in oat cell carcinomas was indicative of poorer survival (p < 0.01 and p < 0.1, respectively). A p53 Li of greater than 60% was a negative prognostic factor in non-oat SCLC (p < 0.05). PCNA LI was highest in non-oat SCLC and lowest in NSCLC; oat cell carcinomas had a mean LI intermediate between NSCLC and non-oat SCLC (NSCLC v oat cell carcinoma p < 0.05 and oat cell v non-oat cell carcinomas p < 0.01). A PCNA LI was not correlated with nodal metastases or survival, but there was a significant positive correlation between PCNA LI and p53 LI (rs = 0.484, p < 0.001). CONCLUSIONS--p53 and PCNA expression differ substantially among the various types of lung carcinomas. Substantial differences were also found between oat and non-oat types of SCLC, indicating that SCLC is heterogeneous as far as proliferation rate and altered p53 expression is concerned. p53 seems to be of some prognostic value. The relation between PCNA and p53 expression indicates that the PCNA gene is slightly upregulated by p53.     

Pulmonary oat cell carcinomas. Expression of plasma membrane antigen correlated with presence of cytoplasmic neurosecretory granules.

A plasma membrane antigen highly associated with pulmonary oat cell carcinoma has recently been identified. Expression of this surface antigen was now examined in routine surgical pathology material from 32 primary lung tumors by immunostaining. The staining patterns of 17 tumors diagnosed as oat cell carcinoma by light microscopy were compared to those of 10 epidermoid carcinomas, four carcinoid tumors, and one lymphocytic lymphoma. In addition, when available, the oat cell carcinoma group was also studied by electron microscopy for demonstration of cytoplasmic neurosecretory granules. Twelve of the 17 oat cell carcinomas and one of the epidermoid carcinomas expressed the antigen. In this group of small cell tumors of the lung, aggrement was found between the expression of this immunochemical marker and the presence of neurosecretory granules in the cytoplasm of the tumors. Demonstration of this surface antigen in routine surgical pathologic material may be a useful aid in the diagnosis of these tumors. The failure of a group of tumors, which satisfied the light microscopic criteria for oat cell carcinoma to stain for the antigen, demonstrates heterogeneity within the oat cell carcinoma group.     

KBA.62: a useful marker for primary and metastatic melanomas

We previously described a novel antimelanoma antibody, designated KBA.62. However, review of the literature showed that only a few studies have reported on this antibody. We report our experience in the diagnosis of melanoma using KBA.62 and its value in both primary and metastatic conditions. In addition to conventional melanomas, we included desmoplastic and spindle cell melanomas, whose diagnosis can be challenging. We also focus on identification of malignant cells in sentinel lymph node biopsies using KBA.62, by comparison with anti-S-100 protein and HMB-45 antibodies, because discrepancies in sensitivity and specificity of melanoma markers have given rise to numerous studies aiming to determine the best panel for the evaluation of sentinel lymph node from patients with melanoma. Overall, KBA.62 was positive in 93% of primary and metastatic melanomas. Interestingly, the 12 cases of desmoplastic and spindle cell melanomas had strongly positive results. In addition, the results of our study performed on a series of 215 sentinel lymph nodes showed that the sensitivity of anti-S-100 protein and KBA.62 antibodies in detecting occult metastasis was similar. Moreover, KBA.62 identified 6 patients (3%) who had confirmed sentinel lymph node metastasis but were negative for HMB-45. The resolution was higher with KBA.62 than that observed with anti-S-100 protein antibody, as the nonmelanocytic positive cells for KBA.62 in lymph nodes were only represented by endothelial cells, which therefore constituted an intrinsic positive control. We conclude that KBA.62 antibody is a useful additional marker for melanoma, specifically in desmoplastic/spindle cell cases and in the context of micrometastasis in sentinel lymph node.     

Characterization of lymphokine fibronectin from guinea pig lymphoid cell culture supernatants.

Fibronectins (FN) in guinea pig lymphoid cell culture supernatants have been studied using a panel of polyclonal and monoclonal anti-FN antibodies to clarify their relationship with macrophage agglutination factor (MAggF), an inflammatory lymphokine sharing many properties with this family of high molecular weight glycoproteins. MAggF contained cellular FN epitopes, and was reversibly bound by antibodies specific for cellular FN. Enzyme-linked immunoassay and inhibition of MAggF activity by monoclonal anti-plasma FN antibodies revealed immunoreactive FN in guinea pig lymphoid cell culture supernatants to share three epitopes with plasma FN and to lack a fourth epitope present in plasma FN. Immunoreactive FN in gelatin-affinity purified lymph node cell culture supernatants was polydisperse; MAggF activity (Mr 410 kD) was associated with only 13% of total immunoreactive FN. Although a low molecular weight FN fragment (Mr 67 kD) was associated with MAggF activity in salt-fractionated peritoneal exudate culture supernatants, it was not possible to generate MAggF activity by limited proteolysis of MAggF-inactive, high molecular weight FN in lymph node cell culture supernatants. We conclude that MAggF is a cellular FN containing a number of epitopes in common with plasma FN and suggest it may be a unique species of cellular FN produced by T lymphocytes involved in initiating delayed hypersensitivity reactions.     

Peripheral airway cell marker expression in non-small cell lung carcinoma. Association with distinct clinicopathologic features.

Paraffin sections of 247 primary and metastatic non-small cell lung carcinomas, the corresponding non-neoplastic lungs, and 75 other specimens were examined by immunohistochemical procedures using a panel of antibodies against the specific products of peripheral airway cells: the major surfactant-associated protein and 10-kD Clara cell protein. Non-small cell lung carcinoma tumors most frequently positive for either peripheral airway cell marker were adenocarcinomas (41%), especially those with papillolepidic growth pattern (56%), followed by large cell carcinomas (25%), other adenocarcinomas (22%), and squamous cell carcinomas (16%). Immunoreactivity was mainly focal and the expression of the two peripheral airway cell markers was discordant. The incidence of marker expression was similar in metastatic and primary non-small cell lung carcinoma. Other organs and their tumors were negative, with few exceptions. Non-small cell lung carcinomas positive for peripheral airway cell markers were associated with younger age and less-intense smoking, and surfactant-associated protein reactivity was more common in women than in men. Peripheral airway cell markers were independent prognostic factors for survival and delayed development of metastases in patients with less-advanced disease. It is concluded that surfactant-associated protein and 10-kD Clara cell protein are specific markers for non-small cell lung carcinoma and peripheral airway cell differentiation and provide useful tools to study the pathogenesis, biology, and prognosis of non-small cell lung carcinoma.     

The demonstration of B-cell, T-cell and myeloid antigens in paraffin sections

The monoclonal antibodies MB1 and MT1, which detect B cells and T cells respectively, have been applied to human lymphoid tissues. The distribution of staining within paraffin sections was compared with that observed using frozen sections and was found to be identical. The antibodies were then applied to paraffin sections of 19 B-cell lymphomas and 10 T-cell lesions in which full immunophenotyping had been performed. The B lymphomas all consisted of a large majority of MB1 positive cells with a variable infiltrate of small MT1 positive lymphocytes. The T cell lesions consisted of MT1 positive cells with few MB1 positive cells except in residual B cell areas of lymph nodes. In paraffin sections from cases of Hodgkin's disease anti-Leu M1 identified Reed-Sternberg cells and their variants and MB1 and MT1 showed a similar distribution of B cells and T cells to that demonstrated in previous studies using frozen sections. The results show that MB1 and MT1 are useful markers for B and T cells in routinely fixed paraffin embedded tissue. In conjunction with anti-Leu M1 they provide a valuable panel of antisera for the examination of lymph nodes and other biopsies when frozen tissue is not available.     

Immunologic methods in cytology: definitive diagnosis of non-Hodgkin's lymphomas using immunologic markers for T- and B-cells

The cytologic diagnosis of malignant lymphoma can be extremely difficult because the cytologic features of the malignant cells in small cell and mixed small and large cell lymphomas may be indistinguishable from those of reactive lymphoid cells. In addition, large cell lymphoma can be difficult to distinguish from undifferentiated carcinoma in cytologic specimens. Using the avidin-biotin immunoperoxidase technic and antibodies to the B-cell markers alpha, gamma, and mu heavy chains and kappa and lambda light chains, to the T-cell markers Leu-1, Leu-2a, and Leu-3a, to the lymphoid marker T200, to TdT, and to Leu-M3, the authors studied 35 cytologic specimens including pleural, cerebrospinal, and ascites fluids and fine-needle aspirations. Immunologic staining allowed them to make a definitive diagnosis of lymphoma or reactive effusion in every case studied and resulted in a significant modification of the morphologic diagnosis in over 50% of cases. In 16 cases the lymphoid cells were monoclonal B-cells: ten expressing IgM kappa; four expressing IgM lambda; one expressing IgA kappa; and one expressing kappa without demonstrable heavy chain expression. Although there are no good markers of monoclonality for T-cells, the authors were able to make a positive diagnosis in two cases of T-cell lymphoid malignancies by the expression of an aberrant phenotype on the malignant cells. The expression of TdT confirmed the diagnosis in one case of common ALL and one lymphoblastic lymphoma. In a patient with a "null cell" large cell lymphoma, the expression of T200 on the malignant cells ruled out the possibility of carcinoma. In 15 cases the marker studies indicated a reactive lymphoid proliferation. The authors conclude that immunologic markers are very useful in the cytologic diagnosis of lymphoma.     

Immunohistochemical analysis of small cell tumors of the thyroid gland: an Eastern Cooperative Oncology Group study.

The majority of small cell anaplastic tumors of the thyroid gland are generally believed to be non-Hodgkin's lymphomas, including most of those formerly classified as small cell carcinomas. Using a panel of antibodies capable of detecting epithelial, neuroendocrine, and B and T cells in paraffin-embedded tissue sections, we studied 68 thyroid neoplasms in which the original diagnosis was small cell carcinoma or lymphoma. Sixty-three of the tumors were identified as lymphomas of B-cell origin on the basis of L26 reactivity used in conjunction with light chain restriction and MB2 immunostaining. Two additional tumors were classified as lymphomas of indeterminate phenotype. Immunophenotyping indicated an epithelial origin in the remaining three tumors. No cases of medullary carcinoma were detected by immunostaining. Histologic review revealed a predominance of large cell and immunoblastic lymphomas, with low-grade lymphomas of mucosa-associated lymphoid tissue histology accounting for only five cases. Our findings indicate that the majority of small cell anaplastic tumors of the thyroid are B-cell lymphomas. Although primary small cell carcinoma of the thyroid may rarely occur, this diagnosis should not be made without immunohistologic confirmation.     

CD68 reactivity of non-macrophage derived tumours in cytological specimens.

AIMS--To investigate the presence of the macrophage associated antigen CD68 in non-haematopoietic tumours. METHODS--Cytological specimens from non-macrophage derived tumours were stained using the alkaline phosphatase anti-alkaline phosphatase immunocytochemical method (APAAP) and three monoclonal anti-CD68 antibodies, Y1/82A, EBM11, and KP1. RESULTS--Reactivity of malignant cells with one or more of the antibodies was seen in 11 out of 40 adenocarcinomas and in one of seven poorly differentiated carcinomas; other neoplasms, including 10 cases of squamous carcinoma, three of malignant melanoma, and four of oat cell carcinoma were negative. Monoclonal antibody KP1 gave the strongest staining and reacted with the highest proportion of neoplastic cells. CONCLUSIONS--CD68 is expressed in a proportion of epithelial tumours although the labelling is usually less intense than in macrophages. Anti-CD68 antibodies should therefore be used as part of a panel in the diagnosis of poorly differentiated neoplasms in cytological material.     

Detection of cell surface antigens in cryostat sections with immunogold-silver staining

Immunogold-silver staining was used for the detection of lymphocyte cell surface antigens in cryostat sections of lymphoid tissues. The sections were incubated with monoclonal mouse antibodies and then with colloidal gold-labeled goat anti-mouse antibodies. They were then immersed in a physical developer, counterstained, and mounted. In light microscopy, the tissue architecture was well preserved, and a dark labeling was seen on the positive cells. Optimal labeling conditions were determined. The distribution of the lymphocyte subsets, as defined by a panel of monoclonal antibodies in tonsil and reactive lymph nodes, was similar to that found with a biotin-avidin-horseradish peroxidase method. The monoclonality of the neoplastic cells in lymph nodes of B-cell non-Hodgkin's lymphomas clearly could be demonstrated. The sensitivity of the technic was comparable with that of the biotin-avidin-horseradish peroxidase labeling method. In addition, immunogold-silver labeling was combined with acid phosphatase cytochemistry.     

Expression of epithelial and neural antigens in small cell and non small cell lung carcinoma

Seventy-one lung carcinomas from 66 different patients were stained with a panel of monoclonal antibodies. Twenty-nine were small cell lung carcinoma (SCLC), 15 adenocarcinomas, 17 squamous carcinomas and 10 large cell carcinomas. Three of the monoclonal antibodies recognize different cytokeratins, three recognize other epithelial antigens and one recognizes a neural antigen. Both formalin-fixed and cryopreserved tumours were studied using an indirect immunoperoxidase method. 23/29 SCLC reacted with all but one of the antibodies which recognize epithelial antigens. This staining was similar to that seen in non small cell lung carcinomas (NSCLC) and provides further evidence that SCLC are true epithelial tumours. All but one of the SCLC stained with the antibody recognizing a neural antigen. This antibody did not stain squamous or adenocarcinomas. However, four of the large cell carcinomas stained well with this antibody, suggesting that SCLC and some large cell carcinomas share a common pathway of differentiation. There were variations of staining seen both within and between tumours. This has obvious implications if immunotargetting with monoclonal antibodies is to be used diagnostically or therapeutically.     

Focal lymphoid aggregates (nodules) in bone marrow biopsies: differentiation between benign hyperplasia and malignant lymphoma--a practical guideline.

AIMS: To provide practical guidelines for the differentiation between benign and malignant focal lymphoid aggregates (lymphoid nodules) in routinely referred bone marrow trephine biopsies, using a synoptic approach including clinical data and histological workup. METHODS: For easy identification of very small lymphoid infiltrates the chloroacetate esterase stain was applied as a screening procedure. This allowed the identification of 491 formalin fixed, paraffin wax embedded specimens with one or more lymphoid nodules. Examination of lymphoid infiltrates included such variables as histotopography, demarcation, cytology, reticulin fibres, and immunohistochemistry with a set of monoclonal antibodies (CD20, CD45R, CD45R0, CD3, CD43). Evaluation of clinical and morphological data was carried out independently. In case of malignant lymphomas, a correlation with corresponding lymph node findings was made. RESULTS: 352 patients had benign focal lymphoid aggregates usually associated with systemic autoimmune diseases, chronic myeloproliferative disorders, toxic myelopathy, and viral infections. Discrete nodular infiltrates of (small cell) malignant lymphomas (n = 93) simulating benign hyperplasia were found in chronic lymphocytic leukaemia, germinal centre cell lymphomas (CB-CC), and lymphoplasmacytic/cytoid lymphomas (LPI). In addition to immunoreactivity, certain histological variables proved distinctive. These were: (1) histotopography, that is, localisation of the lymphoid aggregates within the bone marrow space; (2) relation to the surrounding tissue: margination or interstitial spillage of lymphoid cells; and (3) increase in reticulin fibres. CONCLUSIONS: A combined diagnostic procedure identifying several distinctive features, in particular histotopography and immunohistochemistry, provides a most promising way of discriminating reactive from neoplastic lymphoid nodules in the bone marrow.     

An attempt to produce “pre-T” cell hybridomas and to identify their antigens

With the aim of identifying some of the stages in the development of pre-T cells (cells of the T cell lineage before they enter the thymus), we have produced a large number of hybridomas by the fusion of BALB/c bone marrow cells, bone marrow cells from BALB/c-nu/nu mice, BALB/c fetal liver cells and BALB/c fetal thymocytes with the AKR thymoma BW5147. The hybridomas were selected for the expression of the Thy-1.2 antigen of th3 normal celldonor and for their ability t9produce interleukin 2 (IL 2) upon co-culture with irradiated normal spleen cells. A set of these hybridomas is described in this communication. The hybridomas were then used to immunize rats and to generate monoclonal antibody-producing B cell hybridomas. Most, if not all, of the immunizing hybridomas were derived from pre-T cells as evidenced by the fact that they produce IL 2, and express some of the T cell markers (the Thy-1.2, Ly-1, Ly-2 or L3T4 antigens). The monoclonal antibodies were tested on a panel of pre-T cell hybridomas and on normal cells obtained from spleen, lymph nodes, thymus and bone marrow. The testing was carried out by the microcytotoxicity assay and flow cytometric analysis. Three groups of antibodies could be distinguished. Some antibodies were broadly reactive, being positive with virtually all the clones in the pre-T cell panel and with a substantial fraction of normal lymphoid cells. The identity of the antigens detected by these antibodies remains unknown but they do not seem to correspond to any of the known cell surface markers. Other antibodies reacted only with some of the pre-T cell clones and did not react at all with normal lymphoid cells obtained from adult animals. Finally, other antibodies still reacted only with a minor subpopulation of thymocytes or of thymocytes and bone marrow cells, as well as some of the pre-T cell clones; they did not react with spleen and lymph node cells. These antibodies might be specific for cells in the prethymic phase of the T cell differentiation pathway. They should prove useful for the identification of pre-T cell markers and hence for the isolation of pre-T cells and their functional analysis.     

Immunological marker patterns in granulomatous lymph node lesions

The distribution of various types of lymphocytes and macrophages was studied in 19 cases with granulomatous lymph node lesions using 14 monoclonal antibodies. Cases of sarcoidosis, tuberculosis and atypical mycobacteriosis all showed well demarcated granulomas devoid of B-lymphocytes and natural killer cells. In these cases, T-helper: T-suppressor cell ratios were greater than 2 and poor preservation of the normal lymphoid tissue outside the granulomas was seen. In contrast, cases of non-specific lymphadenitis showed less well-demarcated granulomas always containing B-lymphocytes and natural killer cells, with a T-helper:T-suppressor cell ratio less than 1 and good preservation of the normal lymphoid tissue outside the granulomas. Immunological marker studies may be helpful in the differential diagnosis of granulomatous lymph node lesions, as well as in the study of the pathogenesis of such lesions.