Localization of anti-Leu-M1 (CD15) binding sites in Hodgkin's disease by immunoelectron microscopic examination.

Anti-Leu-M1 (CD15) is a monoclonal antibody used in surgical pathology to diagnoses Hodgkin's disease. By light microscopic immunohistochemistry, anti-Leu-M1 reacts with Reed-Sternberg cells and their variants, notably lacunar cells in nodular sclerosing Hodgkin's disease, as well as granulocytes in Hodgkin's disease. The immunostaining of Reed-Sternberg cells has been characteristically described as a diffuse cytoplasmic pattern with a prominent perinuclear globular component. In addition, irregular plasma membrane reactivity has been observed. To define the intracellular localization of Leu-M1 precisely, the authors performed postembedding immunoelectron microscopy with the protein A-gold technique on sections embedded in Lowicryl K4M from a patient with nodular-sclerosing-type Hodgkin's disease. At the electron microscopic level, gold particle staining indicative of Leu-M1 binding was found within cytoplasmic granules and the Golgi apparatus, as well as focally at the plasma membrane. The cytoplasmic granules were located in a perinuclear region and in the cell periphery. Although the morphology of the granules was suggested of lysosomal structures, immunolabel was not detected on serial sections of these granules with three different antibodies directed against lysosomal antigens.

Diagnostic immunoelectron microscopy in surgical pathology: assessment of various tissue fixation and processing protocols.

We have investigated various tissue fixation and embedding protocols in an effort to allow expanded use of immunoelectron microscopy in diagnostic surgical pathology. A sample of normal human small bowel mucosa was processed using seven different methods for subsequent postembedding localization of chromogranin A. In addition, several archival cases of neuroendocrine tumors previously fixed and routinely embedded for electron microscopy, stored in formalin, or snap-frozen were retrieved and variously processed for chromogranin A localization at the ultrastructural level. Precise localization of chromogranin A in dense core granules was achieved with protein A-gold on sections from all of the processing methods. The methods included retrieval into mild fixative of previously formalin-fixed or snap-frozen tissues followed by embedding in Lowicryl K4M (Polysciences Ltd., Eppelheim, Germany). Thus, tissue processed without foresight of the need for immunoelectron microscopic localization can be successfully used. Since embedding of tissues in Lowicryl K4M has been shown to preserve a variety of antigens, it may prove to be a superior resin for use in diagnostic immunoelectron microscopy.

Lymphoproliferative disorder of granular lymphocytes. A heterogeneous disease.

Lymphoproliferative disorders of granular lymphocytes (LDGLs) represent a family of diseases that are morphologically similar but diverse with regard to immunophenotype, function, and clonality. In this article, we report three informative cases and propose a modification of the current classification of LDGLs. Our first case is an example of natural killer cell LDGLs (CD2+, CD3-, CD16+, CD57+/-). Based on a review of the literature, we suggest that natural killer cell LDGLs can be divided into two subgroups (types 1 and 2) according to the expression of CD57. Reduced expression of CD57 may distinguish between patients with a poorer prognosis. The remaining two cases illustrate examples of T-cell LDGLs (CD2+, CD3+, CD8+, CD57+) that differ mainly in their expression of CD16. The CD16+ T-cell LDGLs (type 1) usually show a clonal rearrangement of the T-cell receptor-beta chain gene, whereas CD16- T-cell LDGLs (type 2) may show a germline configuration, suggesting a reactive rather than a neoplastic process. Pathologists should differentiate LDGLs from other chronic lymphoproliferative diseases, since most cases evolve slowly and aggressive cytoreductive therapy is usually unwarranted.

The pathology of immunoblastic proliferations. Reaction, prelymphoma, lymphoma.

This report has attempted to review the pathology of immunoblastic proliferations, to indicate their similarities and differences, and hopefully to offer some guidelines in the approach to their diagnosis. Their pathology, immunology, and clinical features overlap, making it necessary to evaluate all possible parameters in reaching definite diagnoses. Methods to identify predominant B- or T-cell populations in order to distinguish the neoplasms from the reactive or prelymphomatous lesions can be readily employed using immunohistochemical techniques on either snap-frozen or paraffin-embedded sections. Flow cytometry can be employed to identify major cell populations and evaluate DNA ploidy. DNA probe techniques and cytogenetic evaluation further define the possible clonality of immunoblastic proliferations. Common sense is a basic index for the initial approach to the problem. The abnormal immune lesions present firm challenges in histological diagnosis and in dealing with the concepts of the disease. The immunoblastic sarcomas must be recognized for their status as high-grade lymphomas and separated from the benign reversible reactions and problematic, potentially fatal abnormal immune processes.

Hereditary persistence of fetal hemoglobin presenting as fetal-maternal hemorrhage.

This report describes a case of hereditary persistence of fetal hemoglobin (HPFH) presenting initially as a marginal placental abruption in a primiparous woman at 27 weeks gestation. Persistent but erratic elevation of percent hemoglobin F positive cells, as determined by a modified Kleihauer-Betke method, complicated the remainder of her pregnancy. The clinical impression of placental abruption with possible extension could not be documented by ultrasound or examination of the placenta at delivery. Hemoglobin electrophoresis followed by quantitative fetal hemoglobin first suggested the diagnosis of HPFH, which was confirmed seven months postpartum. Furthermore, the magnitude of percent positive F-cells could be profoundly altered by subtle changes in pH of the acid elution reagent. This case demonstrates that positive acid elution tests for maternal-fetal transfusion may be caused by elevated maternal hemoglobin F. Erratic results, elevated quantitative hemoglobin-F and sensitivity to reagent pH should alert the pathologist to this diagnosis and alter clinical management.

Prolymphocytic transformation of chronic lymphocytic leukemia: a case report of lengthy survival after intensive chemotherapy.

A case of prolymphocytic transformation of chronic lymphocytic leukemia (CLL) is presented in which complete peripheral morphometric remission and lengthy survival were observed after intensive chemotherapy. The case is discussed within the context of the reported therapeutic experience.

Hereditary hemorrhagic telangiectasia. A family study.

The authors report a comprehensive evaluation of the hemostatic system in eight related patients with hereditary hemorrhagic telangiectasia (HHT). Unlike in previous reports, they could find no evidence for abnormalities in platelet aggregation or for qualitative abnormalities of the Factor VIII complex. The authors did identify a subgroup of the more severely affected patients in whom Factor VIIIc levels were increased, with shortened activated partial thromboplastin times (APTTs) associated with mild elevations of antithrombin III.

Detection of factor VIII von Willebrand factor in endothelial cells in first-trimester fetuses.

Factor VIII von Willebrand factor was studied by the immunoperoxidase method in 38 cases of first-trimester therapeutic abortion and two cases of early second-trimester therapeutic abortion. Positive immunostaining was observed in endothelial cells at all gestational ages studied. The findings demonstrate the presence of factor VIII von Willebrand factor in endothelial cells as early as four weeks' gestational age.

A human myeloma-produced monoclonal protein directed against the active subpopulation of von Willebrand factor.

The authors present a study of a human myeloma-produced monoclonal protein (IgG-k) directed against von Willebrand factor that caused an acquired von Willebrand's disease (vWD)-like syndrome. The illness was characterized by upper gastrointestinal bleeding, prolonged bleeding time, decreased platelet adhesiveness, lack of platelet aggregation in response to ristocetin, and a qualitatively abnormal Factor VIII related antigen (vWF) by two-dimensional immunoelectropheresis. Patient plasma or IgG fraction mixed with normal platelet-rich plasma completely inhibited aggregation with ristocetin, but patient platelets resuspended in normal plasma aggregated normally with ristocetin. VWF was markedly elevated and the two-dimensional immunoelectropheresis of vWF revealed a vWD type II-like pattern with an absence of the higher molecular weight forms of the vWF. Marked inhibitory activity was observed in the ristocetin cofactor assay but disappeared at the highest dilutions of patient plasma used in the assay. Infusion of cryoprecipitate following plasmapheresis led to a correction of the bleeding time, improvement in platelet adhesiveness, transient disappearance of inhibitory activity in the Factor VIII ristocetin cofactor assay, and no significant normalization of two-dimensional immunoelectropheresis of vWF. This case demonstrated a myeloma-associated monoclonal antibody that interacted specifically with that part of the Factor VIII molecule necessary for Factor VIII ristocetin cofactor activity, normal platelet adhesiveness, and bleeding time.

Low-dose cytosine arabinoside in the myelodysplastic syndromes and acute myelogenous leukemia.

Seven patients with a myelodysplastic syndrome or "smoldering" acute myelogenous leukemia were treated with cytosine arabinoside in low dosage. Four patients experienced transient, partial responses characterized by improved peripheral blood counts, cessation of transfusion requirements, and a decreased incidence of infection. Treatment was associated with significant, transient hematologic toxicity. The appropriate clinical role of low-dose cytosine arabinoside remains uncertain.

B16 murine melanoma and aging: slower growth and longer survival in old mice.

The growth characteristics and colonization potential of a transplantable melanoma administered to young (3 mo) and old (24 mo) C57BL/6 mice were investigated. After sc injection of B16-F10 melanoma cells, tumor growth was slower, and final tumor volume was less in the older mice. Furthermore, after iv injection of B16-F1 melanoma cells, the number of pulmonary colonies was also less, and the survival was greater in the older mice. These findings indicate an age advantage in this experimental tumor model that may be attributed to either physical or immunologic factors.

Immunoblastic lymphadenopathy: failure of, rather than lack of immunoregulation.

The lymphoid proliferation characteristic of immunoblastic lymphadenopathy is polyclonal and of B cell lineage. This proliferation of B cells could result from an inherent B cell defect, prolonged and pronounced antigenic stimulation, or inadequate immunoregulation. We recently evaluated a patient with this disorder and found excessive T cell mediated in vitro suppression of both the autologous and allogeneic blastogenic response to mitogen. This enhanced in vitro suppression suggests that the clinically observed lymphoid proliferation in this patient occurred because of autonomous or excessively stimulated B cells and not because of a lack of functional suppressor cells.

Childhood leukemia and lymphoma: correlation of clinical features with immunological and morphological studies.

Malignant cells from 49 children with lymphoid neoplasms other than Hodgkin disease were evaluated by surface marker and morphologic studies. We classified the patients into three groups: 36 patients (74%) with acute lymphocytic leukemia; 7 (14%) classified as convoluted lymphocytic lymphoma/leukemia; and 6 (12%) with small noncleaved follicular center cell lymphoma/leukemia. Diffuse marrow involvement was present at diagnosis in some patients in the latter two groups, but their clinical course was not characteristic of the patients with acute lymphocytic leukemia. Male predominance, poor prognosis, and high incidence of central nervous system disease characterized patients in the convoluted lymphocytic and follicular center cell lymphoma/leukemia groups. Clinical presentation in these two groups differed. Proliferations of convoluted lymphocytes were associated with mediastinal masses and proliferations of follicular center cells with intraabdominal tumors. The high incidence of CNS disease in children with neoplasms of convoluted lymphocytes and follicular center cells suggests that these processes have a predilection for the CNS and that patients with them may benefit from CNS prophylaxis.

Convoluted lymphocytic lymphoma in adults: a clinicopathologic entity.

Twelve adults had a distinct clinicopathologic type of malignant lymphoma that closely resembles the mediastinal lymphomas of childhood. Nine patients presented with mediastinal masses, and seven had symptoms related to intrathoracic compression. Seven patients presented with or developed leukemia, and in four of these patients the central nervous system (CNS) became involved. Structurally, the tumor cells had a distinctive stippled chromatin pattern, in addition to the characteristic nuclear convolutions. Tumor cells from five patients were studied immunologically, and, in each case, the tumor cells formed rosettes with sheep erythrocytes. The response to combination chemotherapy was rapid and dramatic, but usually transient, with relapse in the CNS or previously involved sites. The above data strongly suggest that these cases represent a distinct clinicopathologic entity that should be treated similarly to childhood leukemia and lymphoma, with intensive multiple agent induction, CNS prophylaxis, possibly radiation therapy to initially involved sites, and prolonged maintenance.

A morphologic and immunologic surface marker study of 299 cases of non-Hodgkin lymphomas and related leukemias.

This study relateds the cytologic types of the classification of malignant lymphoma of Lukes and Collins to the results of immunologic surface marker studies as part of a systematic multiparameter study of 299 cases of non-Hodgkin lymphomas. The results support the hypothesis that malignant lymphomas are neoplasms of the immune system and involve the B- and T-cell systems and, rarely, histiocytes. The morphologic features of the cytologic types of Lukes and Collins are predictive of the subtypes of lymphoma and considerably more effective than the immunologic surface marker techniques in identifying homogeneous groups. There are considerable methodologic and interpretive problems that are evaluated in detail. The verification of the B- and T-cell subtypes of the Lukes and Collins classification indicates that the time has come to change from the terminology and classification of lymphomas of the past to a modern immunologic approach.

Morphologic and cytochemical comparison of human lymphoblastoid T-cell and B-cell lines: light and electron microscopy.

Human lymphoblastoid cell lines characterized as T- or B-cells by various markers were compared morphologically and cytochemically by light and electron microscopy. Distinct differences in nuclear morphology, amount of cytoplasm, pyroninophilia, and periodic acid-Schiff (PAS) staining enabled us to discriminate between T- and B-cell lines. T-cells had nuclei with an irregular configuration, stippled heterochromatin, and small or absent nucleoli. The scanty cytoplasm of T-cells contained intensely stained, PAS-positive globules and was less pyroninophilic than the cytoplasm of B-cells. B-cells had more rounded, uniform, vesicular nuclei with prominent nucleoli and peripheral heterochromatin. The cytoplasm of B-cells was abundant and strongly pyroninophilic. Transmission electron microscopy generally confirmed these morphologic differences. These findings supported our contention that consistent cytologic features concordant with immunologic markers make it possible to identify certain lymphomas as being of B- or T-cell origin on purely morphologic grounds.