[Cytochemical polymorphism of acid phosphatase in hairy cell leukemia]

Hairy cell leukemia

Hairy cell leukemia is a chronic lymphoproliferative disorder that has been recognized as a separate clinical pathologic entity for the last 25 years. After a decade of discussions about the origin of the neoplastic cell, it has now been well established that hairy cells represent a certain, rather mature stage of B-cell differentiation. Evidence for this has been derived from studies using immunophenotyping with monoclonal and polyclonal antibodies, cytochemistry, and immunoglobulin gene rearrangement. For many years, splenectomy was the only therapy of proven value in hairy cell leukemia. For patients who showed insufficient response to the operation, chemotherapy with low-dose alkylating agents was moderately successful, whereas polychemotherapy often resulted in excessive toxicity. More recently, therapy with alpha-interferon has been shown to be very promising, whereas deoxycoformicin may be an attractive alternative. These new advances in immunology and therapy are reviewed.

Enzyme histochemical demonstration of hairy cell leukaemia in paraffin-embedded tissue sections

Hairy cell leukaemia is a form of leukaemia difficult to diagnose since pancytopenia is often present. Hairy cells contain tartrate-resistant acid phosphatase, and this factor is utilised in the diagnosis of the condition. This study confirms that it is also possible to demonstrate tartrate-resistant acid phosphatase in leukaemic infiltrates in formalin fixed paraffin-embedded tissue sections.

Hepatic involvement in hairy cell leukemia: diagnosis by tartrate-resistant acid phosphatase enzyme histochemistry on formalin fixed and paraffin-embedded liver biopsy specimens

The leukemic infiltrate in the liver in hairy cell leukemia may be easily overlooked in conventional histological slides and an exact classification may not always be possible. In order to facilitate the identification of tricholeukocytes , it is suggested to perform the tartrate-resistant acid phosphatase stain on routinely formalin fixed and paraffin-embedded liver biopsy specimens. Thereby it will be in most cases possible to demonstrate sufficiently enough enzyme activity to establish unequivocally the diagnosis of hairy cell leukemia.

Acid phosphatase and acid esterase activity in neoplastic and non-neoplastic lymphoid cells. A semiquantitative evaluation related to immunological markers in 112 cases

Acid phosphatase (AcP) and acid alpha-naphthylacetate esterase (ANAE) were examined in lymphoid cells from 104 patients suffering from various lymphoproliferative disorders and from 8 healthy controls. Enzyme activities were evaluated by means of a scoring system. Scores of AcP and ANAE were higher in normal T cells than non-T cells. In comparison, the activated T cells in infectious mononucleosis showed increased AcP and decreased ANAE reaction. Malignant T lymphoblasts had a distinct granular AcP positivity in contrast to the faint reactivity observed in cALL blasts, whereas ANAE showed negative or weak reaction in both subsets. High scores and distinct staining patterns for both enzymes were found in T CLL and T prolymphocytic leukaemia, clearly different from the weak activities seen in B CLL, B PLL and some B cell lymphomas. The latter, too, could be distinguished by mutual differences in enzyme reactions. High AcP and ANAE scores were also found in hairy cell leukaemia, and the staining patterns together with the tartrate resistance firmly established the diagnosis. Thus, simultaneous determinations of AcP and ANAE can be of great value in the diagnosis of lymphoid malignancies.

Spongy lymphoid myelofibrosis as a predictor of hairy cell leukaemia or a variant of hairy cell leukaemia without hairy cells?

8 patients with clinical and haematological features suggestive of hairy cell leukaemia are described. During their initial illness morphologic and cytochemical evidence of hairy cell leukaemia were lacking in all but 2 patients. A common highly characteristic histopathologic finding was reticulin fibrosis in the bone marrow, present in all patients at first presentation. The term spongy lymphoid myelofibrosis is proposed for such cases, which may represent a variant type of hairy cell leukaemia or an early stage of the disease.

A human thymoma with prothymocyte-like infiltration

We have examined a human thymoma, round-oval epithelial-type cell with moderate lymphocytic infiltration, whose major lymphocytic component (67%), unlike the minor one (33%), did not form rosettes with sheep red blood cells (E rosettes). However, these cells were of T-cell nature as indicated by the positive staining for both acid phosphatase and beta-glucuronidase, two well-accepted cytochemical markers for T cells. The non-E-rosetting lymphocytes expressed T 10, but not T 3 and T 6 antigens. Moreover, they lacked both peanut agglutinin and Fc-IgG receptors. On the contrary, 71 and 19% of the E-rosetting cells were PNA- and Fc-IgM-receptor positive, respectively. Furthermore, the non-E-rosetting cells were phytohemagglutinin unresponsive. The non-E-rosetting lymphocytes were larger (greater than 7 micron) than the E-rosetting cells and showed a different nuclear chromatin pattern. These immunological, cytochemical, and morphological features strikingly resemble those exhibited by cells (prothymocytes) normally found only in fetal thymus. On the basis of these findings we hypothesize the existence in this thymoma of a prothymocyte-like infiltration.

A micro-culture system for cloning human T lymphocytes in agar

A simple and reproducible single-layer micro-agar culture system for cloning of human T lymphocytes has been described. The system consists of an agar layer, in which mononuclear cells from peripheral blood were suspended, and a liquid overlayer containing the mitogenic substance. The advantages of the described method are a low incubation volume (0.5 ml) and the liquid overlayer. The addition of different test substances to the liquid overlayer is simple and easily controllable. Depending on the agar concentration a different number of formed colonies can be found floating in the liquid phase. The morphological, cytochemical and immunological characteristics of the cells from those aggregates could be easily studied. The T-cell characteristics of formed clusters and colonies was confirmed by immunofluorescence and E rosette formation. The effects of agar, serum and cell concentrations, as well as the mitogenic activation caused by three lectins on the development and number of colonies were studied on day 7, 10 and 14 of incubation.

Acute monocytic leukemia complicating combined-modality therapy for localized childhood Ewing's sarcoma

Rapidly fatal acute monocytic leukemia occurred in an 11-year-old by 33 months after the beginning of irradiation and chemotherapy for non-metastatic pelvic Ewing's sarcoma. At autopsy, no recurrent primary disease was seen. An analysis of this case together with a review of the literature suggests therapy-related leukemogenesis. Thus, the decline in mortality rate for childhood cancer may be accompanied by an increased incidence of second neoplasms in cured children having the potential of a normal life span.

[Chronic lymphoproliferative disorder resembling hairy-cell leukemia (author's transl)]

Seven patients are presented with a chronic lymphoproliferative disorder characterized clinically by splenomegaly, no or discrete lymphnode enlargement, and a varying degree of cytopenia. In blood and bone-marrow smears lymphoid cells of "hairy" appearance are demonstrable which may contain tartrate-resistant acid phosphatase. The finding of a nodular bone-marrow infiltration without fibrosis as well as that of a nodular infiltration of the spleen originating in the white pulp are incompatible with the diagnosis hairy-cell leukemia and place the disease near to chronic lymphocytic leukemia (CLL) or leukemic immunocytoma respectively. A detailed cytologic and cytochemical examination of the infiltrating cells shows deviations from the typical enzymatic pattern of hairy cells and from known enzymatic constellations in CLL and related lymphoproliferative disorders. Thus, we are dealing with an intermediate form, difficult to classify, the separation of which nevertheless seems to be important for therapeutical reasons.

Cytochemical study of thymocytes and T lymphocytes

Fetal and postnatal thymocytes and circulating T lymphocytes were evaluated for six cytochemical reactions. Acid phosphatase activity was present in a high percentage of cells in all threee groups. Beta-glucoronidase and alpha-naphthyl acetate acid esterase were negative in the most immature fetal thymocytes, but become increasingly positive with T-cell maturation. Only the circulating lymphocytes presented a high percentage of N-acetyl beta glucosaminidase, alpha-naphthyl acetate esterase and alpha-naphthyl butyrate esterase positive cells. This study discusses the presence of these enzymes as proportional to different stages in T-cell maturation, and also of certain cytochemical phenotypes characteristic of these stages.

Acid alpha-naphthyl acetate esterase in hairy cell leukemia cells and other cells of the hematopoietic system

The activity of alpha-naphthyl acetate esterase at an acid pH (ANAE) was investigated in 10 cases of hairy cell leukemia. All 10 cases, including two cases with only a few tartrate-resistant acid phosphatase-reactive cells, revealed a moderate or strong ANAE reaction. There was a characteristic pattern of activity consisting of small, medium-size, or large distinct granules often distributed in a semicircle in the cytoplasm, but sparing the nucleus of hairy cells. This reaction pattern was not found in T cells, T cell-derived leukemias, normal B cells, a number of B-cell lymphomas, myeloid cells, myeloid leukemias (including monocyte-derived leukemias), reticulum cell sarcoma, or malignant reticulosis. The cells from some B-cell lymphomas and plasmacytoma showed a relatively homogeneous pattern of fine or moderately coarse ANAE-positive granules that was similar to that of hairy cells only in some cases of plasmacytoma. Thus, fine to coarse granular ANAE reactivity is characteristic of hairy cells and is of potential diagnostic value for hairy cell leukemia.

Hairy cell leukemia. Bone marrow findings in 24 patients

In 24 patients with hairy cell leukemia, histological and fine structural findings from biopsies of the bone marrow are reported and their validity is compared with other diagnostic procedures available. Diagnosis by light microscopy of anterior iliac crest biopsies obtained by the method of myelotomy is possible with a high degree of accuracy. The differentiation of hairy cell leukemia from other myelo- or lymphoproliferative disorders based on cytomorphology as well as patterns of growth is emphasized. Morphological differences between fibrosis in this entity and other lesions such as malignant lymphomas, Hodgkin's disease, osteomyelofibrosis and -sclerosis are emphasized. Electron microscopy of the bone marrow shows single fibroblastic cells with numerous slender cytoplasmic processes randomly dispersed among the hairy cells. These fibroblasts are probably responsible for the synthesis of the reticulin and collagen fibres in their surroundings. Moreover fine structur of the hairy cells demonstrates pinocytic activity but no apparent phagocytosis in contrast to the phagocytic reticulum cells (histiocytes, macrophages). In the bone marrow the precursor cells and the many immature forms of hairy cells exhibit an overall lymphocytoid appearance during their maturation, suggesting a lymphocytic origin.