Cutaneous T-cell lymphoma. Refinement in the application of controversial histologic criteria

Profile of mycosis fungoides in 43 Saudi patients

BACKGROUND AND OBJECTIVES

Mycosis fungoides (MF) is a rare disease; and to our knowledge, there are no reports on its profile in Arabs. The objective of this study was to preliminarily analyze the clinical characteristics of MF patients seen in our institution.

DESIGN AND SETTING

Retrospective review of 140 patients with pathologic or clinical diagnosis or differential diagnosis of MF for the period 2000-2006.

PATIENTS AND METHODS

Pathology reports with diagnosis or differential diagnosis of MF were retrieved and suspected cases were identified and reviewed. For pathologically confirmed cases, sociodemographic, clinical, laboratory, and radiological details were collected. Details of staging, treatment modalities, and disease status at the last follow-up were retrieved.

RESULTS

A total of 43 pathologically confirmed MF patients (skin phototypes IV and V) with a mean age at diagnosis of 33.5 years were reviewed. This comprised 29 males (M:F ratio, 2:1), and the majority (86%) of patients had early-stage (I and II) MF. Twenty-one (48.8%) patients had classic MF; 18 (41.8%), hypopigmented MF; and 4 (9.3%), other variants. The male-to-female ratio was higher in the hypopigmented (3.5:1) than in the classic variant (1.6:1). The mean age at diagnosis was lower in the hypopigmented compared to the classic variant (25 versus 38.8 years, P=.019). The mean duration of follow-up was 27.6 months (range, 1-98 months). At the final assessment, 4 (9.5%) patients recovered; whereas 35 (83.3%) had MF skin disease; 1 had (2.4%) extracutaneous disease; and 2 (4.8%) died of MF.

CONCLUSIONS

MF tends to affect younger Saudi patients. The hypopigmented variant constitutes a significant proportion of MF cases, especially in younger patients.

Case for diagnosis. Mycosis fungoides

An 18-year old female patient presented with a single, erythematous, desquamative plaque. The clearly outlined lesion was situated in the abdominal region. The patient reported that it had been present for the past year and that she had used no previous medication. Histopathology showed lymphocytic infiltration with atypia, principally affecting the superficial dermis with epidermotropism and mild spongiosis. Immunophenotyping revealed a predominance of CD3-positive cells, confirming the diagnosis of mycosis fungoides.

Diagnosis of Mycosis Fungoides

Mycosis fungoides (MF) is the most common form of primary cutaneous T-cell lymphoma. In its early stage it may mimic benign dermatoses both on a clinical and histologic basis. MF usually expresses CD3 and CD4 (T-cell) markers. CD7 is expressed on about 90% of CD4 T cells and is often deficient on malignant T cells. Thus, CD7 may be useful in evaluating the nature of dermal lymphoid infiltrates. The aim of this study was to evaluate the usefulness of immunohistochemical detection of T-cell markers on paraffin-embedded sections, CD3 and CD7 (clone CBC.37), in the differential diagnosis of MF and benign dermatoses. Forty-two patients with diffuse dermal T-lymphocytic infiltrates were selected. Previous clinicopathologic correlation and follow-up had established the diagnosis of MF in 31 patients and benign dermatoses in 11. The mean value of stained cells in MF was 86.45% for CD3 and 53.09% for CD7 (P<0.001); in benign dermatoses it was 79.09% for CD3 and 73.63% for CD7 (P=0.669). CD7 immunolabeling was significantly lower in the MF group (P=0.048). A semiquantitative evaluation revealed a considerable loss of CD7 immunolabeling in comparison with CD3 in patients with MF. The authors conclude that CD7 study may represent a valuable tool in the distinction between inflammation and neoplasia in T-lymphoproliferative skin disorders.

Minimal residual disease in hypopigmented mycosis fungoides

We describe the case of a 13-year-old boy with stage I hypopigmented mycosis fungoides in whom minimal residual disease was detected with T-cell receptor gamma-polymerase chain reaction after the disease was in complete clinical remission. We further cloned and sequenced the T-cell receptor gamma-polymerase chain reaction product of the lesion in remission and found that the original T-cell clone still existed in decreased amounts. The patient was followed up for 3 1/2 years without any new lesions developing. The clinical significance of this residual malignant T-cell clone in mycosis fungoides remains to be elucidated.

Mycosis fungoides - a retrospective study of 40 cases in Hong Kong

BACKGROUND

Mycosis fungoides is rare in Hong Kong and oriental data on the disease are lacking.

METHODS

This is a multiclinic, 13-year, retrospective study to determine the clinicopathologic characteristics, treatment, and disease outcomes of 40 patients with mycosis fungoides/Sézary syndrome seen in the Social Hygiene Service, Hong Kong.

RESULTS

There were 27 males and 13 females with a mean age at diagnosis of 56.4 years. Based on figures in the Social Hygiene Service alone, the incidence in Hong Kong was estimated to be 0.044 per 100,000. Eighty-five per cent of patients presented with skin-limited disease, and pruritus was absent in 40% of patients. A mean of 1.48 biopsies was needed to establish the diagnosis, and only 58% of the mycosis fungoides skin biopsies were reported to be histologically diagnostic of the disease. Atypical lymphocytes, epidermotropism, interface changes, and Pautrier's microabscesses were the four most frequently encountered features that attained statistical significance. Sixty-nine per cent of patients were treated with psoralen-UVA as their initial therapy, and the complete response and relapse rates were 78.3% and 66.6%, respectively. Disease progression to more advanced stages was only seen in 15% of patients. The 5-year survival rates for the whole group and for stage IA and IB patients were 88.8% and 100%, respectively.

CONCLUSION

Mycosis fungoides is rare amongst Hong Kong Chinese and the majority present with skin-limited nonprogressive disease.

Lysophosphatidic acid promotes survival of androgen-insensitive prostate cancer PC3 cells via activation of NF-kappaB

BACKGROUND

Dysregulated cell survival contributes to the poor efficacy of many chemotherapeutic regimens for patients with advanced prostate cancer. In this study we examined ability of the lipid growth factor lysophosphatidic acid (LPA), a G protein-coupled receptor (GPCR) ligand, to promote prostate cell survival.

METHODS

PC3 cells were used as a model to study mechanisms involved in survival of androgen-insensitive prostate cancer cells. Cell survival was measured by FACS analysis of cell cycle parameters after propidium iodide or annexin V and 7-AAD immunostaining. Activation state of nuclear facor-kappaB (NF-kappaB) was determined biochemically by nuclear translocation and transcriptional activation. Human tissue was analyzed for nuclear expression of NF-kappaB by immunohistochemistry.

RESULTS

Molecular dissection of the LPA-regulated PC3 cell survival revealed the sequential phosphorylation of Akt, IkappaB, and transcriptional activation of NF-kappaB. Both Akt and NF-kappaB were required to escape serum deprivation-induced cell death since their inhibition abrogated the LPA-mediated PC3 cell survival. Data from archival human tissue show that NF-kappaB is constitutively activated in prostate cancers, but not in benign prostate tissues.

CONCLUSIONS

Targeted disruption of the LPA receptor-Akt-NF-kappaB signaling axis may be effective for the treatment of androgen-insensitive prostate cancer.

Sezary syndrome: cutaneous immunoperoxidase double-labeling technique demonstrates CD4/CD8 ratio non-specificity

BACKGROUND

Sezary syndrome (SS) is an erythrodermic cutaneous T-cell lymphoma with a leukemic component. Biopsies from these patients may suggest erythrodermic mycosis fungoides or SS but most often are not diagnostic. Additional methods are therefore usually needed to diagnose SS. These include a peripheral blood morphological assessment, flow cytometry, and gene rearrangement studies. The Cutaneous Lymphoma Study Group of the European Organization for Research and Treatment of Cancer has proposed criteria for the diagnosis of SS based on peripheral blood analysis. These include an increased T-cell count with a CD4/CD8 ratio of > or =10, in conjunction with evidence of a T-cell clone in the blood (Willemze et al., Blood 1997; 90: 354-371).

METHODS

We have conducted a study designed to obtain CD4/CD8 ratios by immunoperoxidase staining of skin biopsies, as opposed to flow cytometry. Fourteen biopsies from eight patients with SS and 14 control biopsies were evaluated for CD4/CD8 ratio via double immunostaining.

RESULTS

A CD4/CD8 ratio of >10:1 was seen in 85% of SS biopsies and 43% of controls with horseradish peroxidase used as the CD4 antibody. With alkaline phosphotase used as the CD4 antibody, 54% of SS biopsies and 21% of control biopsies exhibited a >10:1 ratio. We demonstrate that double-labeling immunoperoxidase staining with antibodies to CD4 and CD8 on skin biopsies is not specific for SS. By comparing the CD4/CD8 ratios from skin biopsies in Sezary cases with those from biopsies in inflammatory dermatoses cases, we conclude that flow cytometry remains the most specific method for determining the CD4/CD8 ratios in patients with cutaneous eruptions. Although immunohistochemistry would be useful for laboratories with limited access to flow cytometry, we dismiss such a use, as CD4/CD8 ratios > or =10 were also found in 21-43% of non-Sezary cases examined.

CONCLUSIONS

We conclude that a CD4/CD8 ratio >10:1 on skin biopsy is not sufficiently specific to support a diagnosis of SS.

Criterion by criterion, mycosis fungoides

A wide variety of histologic features have been associated with mycosis fungoides. Virtually all these features can be seen at least episodically in some inflammatory conditions, and little is known regarding which histologic features are most useful in establishing a diagnosis of this challenging condition. Three recent blind histologic studies have addressed this topic, however, and their results and those of other studies are reviewed and compared herein.

Assessment of histologic criteria in the diagnosis of mycosis fungoides

BACKGROUND

The histologic diagnosis of early mycosis fungoides (MF) can be difficult to establish in many instances because the subtle changes observed in patches of MF are also present in many inflammatory dermatoses.

METHODS

To assess the frequency and significance of many of these histologic parameters, we retrospectively reviewed 50 slides from patients with documented MF in patch, plaque, and tumor stages. The diagnosis of MF was unequivocally established either by the progression of patients to advanced stages of the disease or by indubitable histologic findings. In the second phase of the study, we compared the histologic parameters observed in 24 patch stage MF patients with those in 24 non-MF patients. The non-MF group were patients whose pathologic pattern was suspicious for MF, but who definitely did not have MF on clinical grounds. The two groups were matched by histologic pattern. Two different observers evaluated the slides and the intensities of 32 histologic parameters were graded on a four-point scale to minimize the subjective variability in the histologic reports.

RESULTS

On univariate analysis, the following parameters achieved significance in distinguishing MF from non-MF: Pautrier's microabscesses, haloed lymphocytes, disproportionate epidermotropism, epidermal lymphocytes larger than dermal lymphocytes, hyperconvoluted lymphocytes in the epidermis and dermis, absence of dyskeratosis, and papillary dermal fibrosis. None of these features proved to have additional discriminating power on multivariate analysis.

CONCLUSIONS

The efficacy of single histologic features in the diagnosis of early MF is generally poor and, to discriminate MF from its inflammatory simulators, a combination of cytologic and architectural features must be used.

Cutaneous T-cell lymphoproliferative disorders: approach for the surgical pathologist: recent advances and clarification of confused issues

Cutaneous T-cell lymphoproliferative disorders (CTCLs) remain a subject of confusion and controversy. In this review, the authors discuss diagnostic criteria and classification, including the role of immunohistochemistry and gene rearrangement studies. In addition, cutaneous T-cell pseudolymphomas, the current status of parapsoriasis and other premalignant syndromes, and the clinicopathological variants of mycosis fungoides are discussed. CD30-positive lymphoproliferative disorders and a number of rare variants of CTCL including granulamatous slack skin, subcutaneous (panniculitic) T-cell lymphoma, gamma-delta cutaneous lymphoma, NK/NK-like T-cell lymphoma, and primary cutaneous CD8-positive epidermotropic cytotoxic T-cell lymphoma are also considered.