Cerebriform Mononuclear Cells Research Articles

Analysis of β, γ, and δ T-Cell Receptor Genes in Lymphomatoid Papulosis: Cellular Basis of Two Distinct Histologic Subsets

To investigate the histogenesis of lymphomatoid papulosis (LYP), we have analyzed the configuration of the beta, gamma, and delta T-cell receptor (TCR) and Ig genes in DNA from 31 biopsies of 18 patients with this condition and also from peripheral blood mononuclear cells of eight of these patients. Immunoglobulin genes were in a germ-line configuration in all patients, and TCR genes were in a germ-line configuration in six patients. In nine patients, one or two rearranged bands (RB) were detected with both beta and gamma TCR probes and in one patient with beta, gamma, and delta TCR probes. Two patients, in whom beta and delta TCR genes were in a germline configuration, had evidence of multiple discrete rearrangements of gamma TCR genes, consistent with a polyclonal T-cell population. Analysis of multiple biopsies revealed that RB, when present, were identical in different lesions from individual patients. All but one of the peripheral blood samples showed a germ-line configuration. The exception had evidence of a rearrangement of gamma and delta in peripheral blood and a beta and gamma rearrangement within tissue. This study has established that only a proportion of patients with LYP have a monoclonal T-cell proliferation. Correlation with the clinicopathologic and immunophenotypic data revealed that a T-cell clone was limited to patients with Willemze type B LYP or "mixed type" LYP, whereas patients with type A LYP consistently showed a germline configuration of TCR genes. This study indicates that in LYP the atypical hyperchromatic cerebriform mononuclear cells of type B invariably constitute a monoclonal T-cell population whereas the atypical CD30 positive type A cells represent a proliferation of cells of non-B, non-T-cell lineage.

Characteristic Immunologic Profile of Large Atypical Cells in Lymphomatoid Papulosis

In 1968, Macaulay coined the term lymphomatoid papulosis to describe the paradox of a clinically benign, self-healing skin eruption resembling pityriasis lichenoides acuta, in which the histology was unexpectedly that of a malignant lymphoma. 1 Willemze et al 2 subsequently classified lymphomatoid papulosis into two principal histologic types: type A, in which large atypical cells with characteristics of Reed-Sternberg (RS) cells are prominent; and type B, in which atypical cerebriform mononuclear cells similar to mycosis fungoides cells predominate. The presence of both histologic types in different but concurrent lesions and the finding of transitional forms in some biopsy specimens suggested that the two types were somehow related. Further clarification of the histogenesis of lymphomatoid papulosis, the relationship between the principal histologic types, and the nature of the atypical cells awaited the development of new monoclonal antibodies for their investigation. In this issue of theARCHIVES, Tokura

Histopathologic studies in Sézary syndrome and erythrodermic mycosis fungoides: A comparison with benign forms of erythroderma

Histologic sections from eleven patients with Sézary syndrome were reviewed and compared with those of four patients with erythrodermic mycosis fungoides and twenty-four patients with a benign form of erythroderma, including fifteen patients with chronic dermatitis, four with a generalized drug eruption, and five with an erythrodermic psoriasis. The most important discriminating histologic feature in patients with Sézary syndrome was the presence of a monotonous bandlike or perivascular infiltrate in the papillary dermis, mainly composed of large cerebriform-mononuclear cells, as seen in seven of eleven Sézary syndrome patients. Pautrier's microabscesses were observed in seven of eleven Sézary syndrome patients, two of four patients with erythrodermic mycosis fungoides, but not in any of the patients with a benign form of erythroderma; their presence was therefore considered a reliable criterion in differentiating erythrodermic cutaneous T cell lymphoma from benign forms of erythroderma. However, features of chronic dermatitis were often found superimposed on those of Sézary syndrome and were even predominating in four of eleven Sézary syndrome patients. Moreover, four patients with a benign form of erythroderma showed a histologic picture suggestive of cutaneous T cell lymphoma. Therefore, in dubious cases repeated skin biopsies, additional investigations of lymph nodes and peripheral blood, and careful follow-up are mandatory for the achievement of a correct diagnosis.

Lymphomatoid papulosis expresses immunophenotypes associated with T cell lymphoma but not inflammation

Twelve skin biopsy specimens of lymphomatoid papulosis from nine patients were studied immunohistologically. The large atypical cells morphologically resembled Reed-Sternberg cells in six cases and large cerebriform mononuclear cells in three cases. These cells expressed pan-T cell antigens (Leu-4 and/or Leu-5) and helper T cell antigen (Leu-3) in each case. They also expressed activation antigens: HLA (human lymphocyte antigen)-DR, HLA-DQ, Tac, and T9. Reactivity of many nuclei with Ki-67 indicated a high proliferative index. Phenotypic abnormality of the large atypical cells was evident by their deficiency of T cell antigens Leu-1 and/or Leu-9 in eight of nine cases. Neither Ki-1 nor Leu-M1 were reliable markers for lymphomatoid papulosis in this series, since large atypical cells were Ki-1-positive in only three of eight cases and were Leu-M1-negative in all eight cases tested. The remainder of the cutaneous infiltrate consisted of small T cells, macrophages, Langerhans cells, and granulocytes. The small T cells expressed a normal phenotype except in some cases associated with mycosis fungoides in which they were deficient in various T cell antigens. Comparison of concurrent lymphomatoid papulosis and mycosis fungoides skin biopsy specimens in two patients revealed that they were composed of phenotypically distinct T cell subpopulations. These results indicate that the large atypical cells of lymphomatoid papulosis are a proliferating population of activated helper T cells that are deficient in certain T cell antigens. Such abnormal T cell phenotypes are common in T cell lymphoma but are rarely, if ever, observed in cutaneous inflammation. In conjunction with the cytologic atypia, aneuploidy, and association with other lymphomas documented in this or previous reports, these data suggest that lymphomatoid papulosis represents a T cell lymphoproliferative disorder rather than an inflammatory disorder.

Diagnostic Criteria in Sézary's Syndrome: A Multiparameter Study of Peripheral Blood Lymphocytes in 32 Patients with Erythroderma

In order to define additional diagnostic criteria for the early diagnosis of Sézary's syndrome (SS), peripheral blood lymphocytes of 32 patients with erythroderma, including 8 patients with SS, 4 patients with erythrodermic mycosis fungoides, 14 patients with an erythroderma on the basis of atopic or chronic dermatitis, and 6 patients with erythrodermic psoriasis, were investigated by computer-assisted morphometry. The degree of nuclear indentation, expressed as the nuclear contour index (NCI), was measured on electron micrographs. The mean NCI and the percentages of cerebriform mononuclear cells (CMC), defined by a NCI greater than or equal to 6.5, were calculated. In addition, the percentages of lymphocytes, T and B cells, and the distribution of T-cell sub-populations as defined by Fc-receptors (T mu, T gamma) and monoclonal antibodies (OKT3, OKT4, OKT8, HLA-DR) were determined. Statistical analysis showed as most discriminating parameters for the differentiation between SS and benign forms of erythroderma: high percentages of lymphocytes (50% or more), an expanded OKT3+, OKT4+ population with an OKT4/OKT8 ratio greater than 10, a mean NCI value greater than or equal to 5.5, the presence of more than 20% CMC, as well as the presence of cells with a NCI greater than or equal to 11.5. The total leukocyte and lymphocyte counts, as well as the percentages of B, T, T mu, and T gamma cells had limited value for the early diagnosis of SS.

Immunological, cytochemical and ultrastructural studies in lymphomatoid papulosis.

In lymphomatoid papulosis two histological types can be distinguished, i.e. type A and type B. In the present study various immunological, enzyme-histochemical and ultrastructural techniques were used to investigate the cellular infiltrate in both types of lymphomatoid papulosis. The type A lesions showed a predominance of large atypical cells, relatively few T cells and few or no Langerhans or related cells, as defined by a positive staining for OKT6 and NA I/34 antisera. The immunological, cytochemical and ultrastructural characteristics of these large atypical cells resembled those of the Langerhans cell/interdigitating reticulum cell series. The morphology and marker profile of these large cells resembled those of Reed-Sternberg cells, which suggests a relationship between lymphomatoid papulosis type A and Hodgkin's disease. The type B lesions showed a predominance of small, medium-sized and large cerebriform mononuclear cells with the phenotype of activated T helper cells, and numerous Langerhans and/or related cells. Their cellular composition was similar to that observed in the early stages of mycosis fungoides.

The clinical and histological spectrum of lymphomatoid papulosis.

A review of sixty-four biopsies from sixteen patients with lymphomatoid papulosis revealed two characteristic histological types (type A and type B), which also had a different clinical behaviour. In lymphomatoid papulosis type A lesions, four histological patterns corresponding with the age of the lesion could be distinguished. Such a relationship was not found in type B lesions. The findings of transitional forms in some biopsy specimens, showing histological features of both type A and type B, and the presence of both types in different but concurrent lesions, suggests that these two types are not different entities but rather represent the ends of a spectrum. At least two different populations of atypical cells can be distinguished in lymphomatoid papulosis. Apart from the atypical cerebriform mononuclear cells, which are T-lymphocytic in origin and predominant in type B lesions, large atypical cells with vesicular nuclei, prominent nucleoli and abundant cytoplasm are found, particularly in type A lesions. Preliminary immunohistochemical and cytochemical investigations suggest that these cells are not lymphoid in origin, but are related to the Langerhans cell series.

The prognostic value of membrane markers and morphometric characteristics of lymphoid cells in blood and lymph nodes from patients with mycosis fungoides.

For 26 patients with mycosis fungoides (MF), the type and extent of the skin lesions, the percentage of cerebriform mononuclear cells (CMC), and T and B lymphocytes in the peripheral blood and lymph nodes were correlated with MF involvement of regional lymph nodes, the clinical course, and response to therapy. Skin tumors and an involvement of more than 25% of the skin correlated well with lymph node involvement. Normal percentages (2--18%) of CMC in the peripheral blood were found for MF patients without lymph node involvement when compared with those found for patients with benign erythroderma and healthy donors. Elevated circulating CMC percentages (greater than 20%) were observed in 9 of 11 MF patients with lymph node involvement. In the lymph node cell suspensions from nine of ten MF patients with lymph node involvement, increased CMC values were found (greater than 15%), whereas two of three MF patients without lymph node involvement showed percentages comparable (4% and 7%, respectively) with those of the control lymph nodes. In the peripheral blood of patients with MF, decreased percentages of T cells (less than or equal to 55%) were found predominantly for patients with lymph node involvement, whereas normal percentages were noted for most of the patients without lymph node involvement. No consistent differences in the percentage of T and B cells in the lymph node cell suspensions were found between MF patients with and without lymph node involvement. Patients with lymph node involvement showed in general a partial response to therapy with an unfavorable clinical course in contrast to patients without lymph node involvement. Increased percentages of CMC (greater than 20%) and decreased percentages of T cells (less than or equal to 55%) in the peripheral blood, the presence of skin tumors, and involvement of more than 25% of the skin are prognostically unfavorable signs for patients with mycosis fungoides.

The relevance of morphometry in the differential diagnosis of cutaneous T cell lymphomas.

Morphometric analysis of lymphoid cells in the skin was used to differentiate between cutaneous T cell lymphomas (CTCL), i.e. mycosis fungoides (MF) and Sézary syndrome (SS), and chronic benign skin diseases. In electronmicrographs of the skin lesions from twenty patients with CTCL (group I), fourteen patients with chronic benign skin diseases (group II) and twenty-nine patients suspected of CTCL (group III), the degree of nuclear indentation of lymphoid cells, expressed as the nuclear contour index (NCI), was measured. Analysis of the NCI histograms of the infiltrating cells of group I and group II permitted us to derive classification criteria for allocating all patients correctly with a high probability (greater than or equal to 95%) in the appropriate group. Only one case was classified with a low probability (71%). The classification criteria are based on the presence of cerebriform mononuclear cells (CMC) with highly indented nuclei (NCI greater than or equal to 11.5) and the frequency distribution of CMC in the skin infiltrates expressed as the 25th and the 70th percentiles of the NCI histograms (P25 + P70). When these criteria were tested on twenty-nine patients suspected of CTCL, twenty cases were classified as malignant, nine as benign. During the follow-up period, out of the twenty patients classified as malignant, seventeen patients appeared to have or develop MF, whereas two patients had lymphomatoid papulosis and one patient is still suspected of MF. Of the nine patients classified as benign, eight patients were proven to have benign skin diseases whereas one developed MF in the follow-up period of up to 4 years. The classification results based on morphometry proved to be more sensitive than those based on DNA cytophotometry. It is concluded that morphometric analysis of lymphoid cells in the skin is of diagnostic relevance in the differential diagnosis of CTCL.

Early diagnosis of mycosis fungoides and Sézary's syndrome by morphometric analysis of lymphoid cells in the skin.

Mycosis fungoides (MF) and Sézary's syndrome (SS) are cutaneous T-cell lymphomas characterized ultrastructurally by the presence of lymphoid cells with deep and narrow nuclear indentations (cerebriform mononuclear cells or CMC). Early diagnosis of MF and SS is difficult because in their early stages they often resemble various forms of chronic, benign skin lesions. By measuring the frequency distribution of a nuclear shape parameter (nuclear contour index or NCI) of lymphoid cells in skin infiltrates using computer assisted planimetry, we tried to classify suspect cases into the malignant and benign groups. From 12 patients with MF or SS (malignant group) and 11 patients with chronic, benign skin lesions (benign group) the frequency distribution of the NCI of the lymphoid cell population was measured. Nonlinear discriminant analysis selected the 70th and 25th percentile of the NCI distribution of the lymphoid cells in the skin infiltrates as parameters by which these patients could be classified correctly into the malignant or benign groups with a probability of over 95%. The predictive value of these parameters was tested on ten patients suspected of having cutaneous T-cell lymphomas. Three cases were classified as benign and 7 as malignant. In a three-year follow up cutaneous T-cell lymphomas did not develop in any of the 3 cases classified as benign, MF developed in 5 of 7 cases classified as malignant, 1 patient has lymphomatoid papulosis and 1 patient is still suspect for MF. These results are compared with those of DNA cytophotometry performed on skin imprint preparations. It is concluded that morphometry of lymphoid cells in skin lesions of patients suspect for MF and SS can make an important contribution to an early diagnosis of MF or SS.

C-type virus-like particles specifically localized in Langerhans cells and related cells of skin and lymph nodes of patients with mycosis fungoides and Sezary's syndrome. A morphological and biochemical study.

C-type virus-like particles were found in 7 skin biopsies and in 4 lymph nodes from 7 patients with mycosis fungoides (MF). In addition, such particles were also found in skin biopsies from 2 patients with Sezary’s syndrome (SS). The particles were invariably found in cells derived from the mononuclear phagocytic series i.e. Langerhans cells and “related cells”, but never in cerebriform mononuclear cells (CMC) nor in any other cell-type. No virus-like particles were found in control specimens consisting of skin biopsies from 8 patients with chronic benign skin lesions and peripheral lymph nodes from 4 patients with unrelated diseases. In one patient with MF particles possessing some characteristics of retraviruses could be released from skin lesions. They band at a density of about 1.16 g/cm3 in a sucrose gradient and exhibit reverse transcriptase activity (RNA-dependent DNA-polymerase activity). Electron microscopy of the skin lesions and of the 1.16 g/cm3 sucrose gradient fraction confirmed the presence of C-type virus-like particles. The presence of C-type virus-like particles only in Langerhans cells and in related cells: i.e. indeterminate cells in the skin and IDC in lymph nodecells with a specific preference for T cell regions-from patients with MF and SS might be related to the aetiology of these cutaneous T cell lymphomas.

T-cell nature of leukaemic cells in a case of Sezary's syndrome with 'null-cell' features.

alpha-naphthyl acetate esterase (ANAE) activity has been investigated in leukaemic cells from peripheral blood in a typical small-cell Sézary syndrome (SS) case in which cerebriform mononuclear cells failed to form E rosettes. The 'dot-like' ANAE positivity found in the majority of these neoplastic cells strongly supports a T-cell origin. In addition, a non-monocytic, non-B-cell nature of Sézary cells is indicated by the lack of Ia-like antigens. Finally, there is evidence of a distinct portion of Sézary cells simultaneously expressing ANAE activity and Fc IgM receptors.

Cerebriform (Sézary like) mononuclear cells in healthy individuals: a morphologically distinct population of T cells. Relationship with mycosis fungoides and Sézary's syndrome.

The ultrastructural and surface marker characteristics of lymphocytes in human cord blood and peripheral blood of healthy donors were studied with respect to the presence of cerebriform mononuclear cells similar to those occurring in the dermal infiltrate of patients with mycosis fungoides (mycosis cells), and the skin infiltrate and peripheral blood of patients with Sézary's syndrome (Sézary cells). Cerebriform monuclear (Sézary-like) cells are characterized by a high nucleus-cytoplasm ratio, deep and narrow nuclear identations, condensed chromatin at the nuclear membrane and cytoplasm poor in organelles. Of the lymphoid cells in human cord blood and peripheral blood of healthy donors 6.7 and 8.7% respectively proved to be cerebriform mononuclear cells. Since these cells invariably form E-rosettes they are part of the T-cell population in healthy individuals. The finding of similar cells in the skin infiltrate of patch test areas of patients allergic to rubber, formalin and peruvian balsam--an expression of cellular immunity mediated by T-cells--suggests that these cells are reactive T cells. Not all (up to 85%) of the cerebriform mononuclear cells in patients with mycosis fungoides and Sézary's syndrome have T-cell membrane characteristics as shown by E-rosette formation. This suggests the presence of two populations of cerebriform mononuclear cells in mycosis fungoides and Sézary's syndrome. The relationship of cerebriform T cells as seen in healthy individuals with cerebriform or atypical mononuclear cells occurring in the Sézary syndrome and mycosis fungoides is discussed.