DNA content of mycosis fungoides cells

Defining early mycosis fungoides

This editorial review summarizes the results of 5 meetings sponsored by the International Society for Cutaneous Lymphoma at which the clinicopathologic and ancillary features of early mycosis fungoides were critically examined. Based on this analysis, an algorithm was developed for the diagnosis of early mycosis fungoides involving a holistic integration of clinical, histopathologic, immunopathologic, and molecular biological characteristics. A novel aspect of this algorithm is that it relies on multiple types of criteria rather than just one, for example, histopathology. Before its finalization, the proposed diagnostic algorithm will require validation and possibly further refinement at multiple centers during the next several years. It is anticipated that a more standardized approach to the diagnosis of early mycosis fungoides will have a beneficial impact on the epidemiology, prognostication, treatment, and analysis of clinical trials pertaining to this most common type of cutaneous lymphoma.

Multiparametric image cytometry in mycosis fungoides

Eighteen cases of early mycosis fungoides were compared with 18 cases of eczematous dermatitis by multiparametric image cytometry. A minimum of 100 lymphocytes was measured in each case. A large number of measurements was acquired for each lymphocyte, characterizing nuclear DNA content, area, shape, and texture. There were significant differences between the two groups, especially in nuclear DNA content and texture. These differences allowed the two groups of nuclei to be distinguished with 78% accuracy. The two groups of lesions were distinguished with 94% accuracy, using neural network analysis.

Prognostic significance of DNA cytometry in cutaneous malignant lymphomas

The current classification of cutaneous malignant lymphomas (ML) into low-grade and high-grade lymphomas was found to be of limited reproducibility and permitted only a rough prediction about outcome. With this in mind, the relationship between nuclear DNA content and both prognosis and histologic grading according to the Kiel classification was evaluated on Feulgen-stained imprint specimens. In all, 49 cases of malignant non-Hodgkin's lymphoma, primary of the skin or with an involvement of the skin as one of the first symptoms, were studied using a computerized high-resolution image analysis system. The 2c deviation index (2cDI), which reflects the variation of the nuclear DNA values around the normal diploid peak, was found to be the best prognostically relevant criterion. Using the 2cDI, a significant discrimination (P less than 0.001 in the U test) between low-grade and high-grade ML was achieved. The prognostic benefit of the 2cDI was well documented by a significant inverse correlation between the 2cDI and the period of time until the patients progressed at least into one higher stage or died of lymphoma (r equals -0.63, P less than 0.05). In addition, the 2cDI enabled prognosis of the course of disease. In the group with low 2cDI values (2cDI, less than 0.5), no progression of the disease was observed after 1 year. In the groups presenting with a 2cDI between 0.5 and 1.0 and higher than 1.0, a progression was found in 57% and 64% of the cases studied, respectively. In conclusion, these measurements indicate that the determination of DNA distribution patterns in imprint specimens allows a precise and objective prognostic evaluation of cutaneous ML.

Differentiation between lymphomas and pseudolymphomas of the skin by computerized DNA-image cytometry

The histologic and immunohistologic differential diagnosis between pseudolymphomas (PL) and malignant lymphomas (ML) of the skin can be difficult. Since DNA cytometry has been found to be of both diagnostic and prognostic value in various neoplasms, its ability to discriminate between ML and PL in Feulgen-stained imprints of 17 PL and 49 ML skin biopsies was examined by high-resolution image analysis. The reliability of the following algorithms of DNA distribution was evaluated: 1) 2cDI (2c-deviation index), which reflects the variation of the nuclear DNA values around the diploid DNA peak; 2) percentage of cells having a DNA value greater than or equal to 5c (5cER; 5c-exceeding rate); 3) percentage of cells presenting with a DNA value greater than or equal to 4c (4cER). A 2cDI of 0.1 was found to be the most reliable marker for the differentiation between PL and ML. On the basis of this feature, 16 of 17 cases of PL and 46 of 49 cases of ML were correctly classified. The sensitivity, specificity, and efficiency of this feature were 94%. A 5cER greater than or equal to 1% had a specificity of 100%, but the sensitivity was only 43%. For the 4cER, a sensitivity of 61% and a specificity of 94% were found. In conclusion, the calculation of the 2cDI and the 5cER based on high-resolution image analysis provided additional helpful diagnostic features, and therefore should be included as a diagnostic tool. If the 5cER is at least 1%, the diagnosis of a ML can be confirmed with a specificity of 100%.

Cytophotometric analysis on nuclear DNA contents of human scirrhous gastric carcinoma

DNA ploidy patterns in six cases of scirrhous gastric carcinoma were examined by scanning cytophotometry, using 15 micron paraffin sections which were confirmed to involve a single whole nucleus. Measurements of DNA content were performed in 70 to 100 cancer cells each in intramucosal (m), submucosal (sm), propria muscular (pm) and subserosal (ss) parts of the tumor. Out of the six scirrhous gastric carcinomas, four were generalized ones and two were localized ones. Aneuploidy with diploid stem line (mosaic pattern) was seen in two cases (generalized type). The remaining four cases (two cases of localized type and two cases of generalized type) were composed of a diploid stem cell line with or without polyploid cells. Stem cell line did not change through the gastric wall, but in three cases (one diploid case and two mosaic cases), the number of polyploid or aneuploid cells significantly increased at the deep infiltrative site. These findings suggest that DNA ploidy of scirrhous gastric carcinoma is determined at an early stage of tumor proliferation and that the increase of polyploid cells and aneuploid cells in the deeper layer might participate in tumor progression. Moreover, there was no evident correlation between the increase of polyploid or aneuploid cells and the expression of oncogene products or EGF related growth factors.

DNA-cytophotometry of lymph node touch imprints in cutaneous T-cell lymphoma

Scanning DNA-cytophotometry was performed on touch imprints of 26 lymph nodes (LN) obtained from 25 patients with cutaneous T-cell lymphoma (CTCL), stained by the Feulgen technique, and interpreted without knowledge of histopathologic diagnosis. Four patterns of DNA distribution were identified, but only histograms that demonstrated cells containing nuclei with more than 4C DNA content (hypertetraploidy) reliably distinguished LN involved with CTCL from LN with reactive changes; for example, dermatopathic lymphadenitis. An abnormal DNA histogram with evidence of hypertetraploidy was demonstrated in 9 of 12 LN showing histopathologic evidence of involvement compared with no abnormal histograms in 14 LN without histopathologic involvement. One LN that was diffusely involved with CTCL had a DNA distribution characteristic of a relatively high level of cell proliferation, but without definite hypertetraploidy. Cytogenetic studies on the blood of this patient, who had Sézary syndrome, demonstrated a clone of lymphocytes with a pseudodiploid karyotype without a related polyploid subline. The remaining two histopathologically involved LN had normal DNA histograms; these LN were only focally involved with CTCL. These observations indicate that DNA-cytophotometry correlates well with the histopathologic findings in LN diffusely involved with CTCL, but may be normal in LN with focal involvement or in those that contain cytogenetically abnormal cells with a near-diploid DNA content.

Clinical implications of immunologic phenotyping in cutaneous T cell lymphoma

The composition of cutaneous lesions from 158 patients with confirmed cutaneous T cell lymphoma, 91 patients with suspected cutaneous T cell lymphoma, and 145 patients with lymphoid disorders other than cutaneous T cell lymphoma was quantitated in situ with the use of commercially available murine monoclonal antibodies that identify the Pan T, T-helper/inducer (Th), T cytotoxic/suppressor (Ts), and Pan B lymphocyte subsets. On average, cutaneous infiltrates of confirmed cutaneous T cell lymphoma were found to contain significantly more Th and less Ts or Pan B cells compared to benign lymphoid disorders. Moreover, when analyzed in terms of the type of lesion examined by biopsy, the absolute amount of Th cells progressively expands with increasing magnitudes of infiltrate in the dermis while the amount of Ts and Pan B cells remains relatively constant among lesions. A useful diagnostic criterion (anti-Leu 1/4 greater than or equal to 70% and anti-Leu 3a/anti-Leu 2a ratio greater than or equal to 6) correctly discriminated between cutaneous T cell lymphoma and non-cutaneous T cell lymphoma in 87.5% of cases. A positive immunodiagnostic result also may be useful for the prediction of subsequent histopathologic confirmation of cutaneous T cell lymphoma in patients who have suspect lymphoid infiltrates, such as alopecia mucinosis or idiopathic generalized erythroderma, when first seen. With the use of multivariate analysis, stage and possibly the percentage of Th cells within the T cell component in cutaneous infiltrates were covariates with significant relationships to survival in patients with confirmed cutaneous T cell lymphoma. In addition, Ts cells in infiltrates did not correlate significantly with observed responses to topical treatment and subsequent course in pretumorous mycosis fungoides. These results indicate that Ts cells play little biologic role in modifying the natural history of cutaneous T cell lymphoma.

Early diagnosis of cutaneous T-cell lymphoma by DNA flow cytometry on skin biopsies

Seven patients with mycosis fungoides early plaque stage with nondiagnostic histology had single-cell DNA content measured by flow cytometry for estimation of clonal ploidy. A total of 63 skin specimens were examined by histology and DNA measurements concurrently during the course of the disease. In addition, six patients had blood samples studied. All seven patients demonstrated aneuploid DNA histograms when the specimens were obtained from skin lesions. In 36 specimens the aneuploid peaks were hyperdiploid. By sequential studies one patient demonstrated two different aneuploid cell clones, one located in the hyperdiploid region and one located in the hypotetraploid region. All patients developed mycosis fungoides which were histologically confirmed, and the time from first aneuploid DNA histogram until diagnostic histology varied from 5 to 21 months (median, 12 months). In six of the patients a normal diploid DNA histogram was found of peripheral blood lymphocytes. The finding of aneuploidy in patients with early mycosis fungoides who still have a nondiagnostic histology emphasizes the value of flow cytometry as a complementary diagnostic aid which facilitates an early diagnosis.

The relationship between lymphocyte nuclear morphology and cell cycle stage in lymphoid neoplasia

A significant percentage of lymphoid cells isolated from three lymphoid neoplasms (nodular lymphoma mixed cell type, mycosis fungoides, and Sézary syndrome) had tetraploid or near-tetraploid DNA content, as determined by flow cytometric analysis. In each case, a morphologically distinct population of cells with large, irregular nuclei was present, the percentage of which corresponded to the percentage of tetraploid cells. In a fourth case (diffuse "histiocytic" lymphoma), cells were sorted on the basis of DNA content from the G0-G1 compartment and compared morphologically to cells sorted from the S-G2(M) compartment. The G0-G1 cells has clumped nuclear chromatin, lacked prominent nucleoli, and had a mean nuclear diameter of 10.18 +/- 1.22 micrometer. The sorted cells with S-G2 (M) DNA content had one to several prominent nucleoli and less clumped nuclear chromatin, and they were significantly larger, with a mean nuclear diameter of 13.76 +/- 1.59 micrometer (p less than 0.00001). These preliminary results suggest that, in lymphoid malignancies, certain morphologic characteristics of individual lymphoid cells are related to their DNA content (level of ploidy) and/or the stage of the cell within its division cycle.

Proliferation kinetics of the dermal infiltrate in cutaneous malignant lymphomas

To obtain information about the role of local proliferation in the pathogenesis of dermal infiltrate in malignant cutaneous lymphomas, we determined the percentage of 3H-thymidine-labeled infiltrating cells (3H-index). A linear correlation was found between proliferative activity and clinical stage in mycosis fungoides, i.e., the 3H-index is moderately elevated in stage I and high in stage III. The 3H-index is within normal range in dermal infiltrate of Sézary syndrome, diffuse lymphocytic lymphoma, as well as in lymphocytoma benign cutis. In parapsoriasis en plaques two groups can be distinguished: in the small-plaque variant (chronic superficial dermatitis) the 3H-index is low, whereas the large-plaque variant (prereticulotic poikiloderma) shows strong proliferative activity. Thus, determination of proliferative activity seems to give new insights into the pathogenesis of dermal infiltrate in cutaneous lymphomas.

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.

Further similarities between Sézary syndrome and mycosis fungoides

Sézary syndrome and mycosis fungoides, both malignant Non-Hodgkin lymphomas, although characterized as specific entities, show a close relationship. This is based on striking similarities not only uith respect to morphological, cytophotometrical, cytogenetical and immunological findings, but also with respect to a typical common reaction pattern to photochemotherapy.