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Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare type of peripheral T-cell-derived lymphoma. A 30-year-old Japanese woman presented, complaining of skin lesions on her left hip. The cellular constituents in this SPTCL were of a mixed population. Not only tumor lymphoid cells, but also many macrophages, endothelial, fibroblasts, and fat cells were seen. The tumor cells immunostained positive for CD3 and CD8, but negative for CD4. Cytotoxic injury granule-related antigens of TIA-1 and granzyme B were positive in tumor cells. CD30. CD56, EBNA-2, LMP-1, CD20cy, and CD68 were all negative in the tumor cells. An ultrastructural study revealed that the lymphoma cells showed primitive cellular contacts with the neighboring tumor cells, interacted with the short villous dendrites of the opposing macrophage and fibroblast cellular membranes, and were associated with the vascular constituents, fat cells, and the extracellular matrix. Small aggregations of the granules were frequently seen in the cytoplasm. It was speculated that the tumor cells to some extent preserve the cytotoxic T-cell structure and function, have active cellular and cell-to-matrix interaction, contain characteristic cytoplasmic granules, and reveal unique histology like panniculities.

Although it has been well established that the human T cell lymphotropic virus type I (HTLV-I) causes adult T cell leukemia/lymphoma (ATLL) in regions of the world where this virus is endemic, its role in the pathogenesis of cutaneous T cell lymphoma (CTCL) in the Western world has been less well established. Most patients with CTCL are negative for antibodies to the structural proteins of HTLV-I, and thus a causative role for this virus is usually dismissed. However, the Tax sequence of HTLV-I has been found in the peripheral blood mononuclear cells of practically all patients with CTCL. Such patients express Tax mRNA and have antibodies to p40Tax, the protein encoded by this sequence. Sequence analysis of a 159-bp region of Tax extracted from CTCL cells proved to be homologous with the same region prepared from a cell line infected with prototypic HTLV-I. By in situ PCR, Tax has been demonstrated in the lymphocytes infiltrating the skin as well as in the keratinocytes of such patients. Apart from the pathophysiologic and clinical interest of these studies, these observations may have therapeutic implications. In vitro, the proliferation of HTLV-I-transformed cells can be inhibited by antisense to HTLV-I Tax. Since Tax has not been identified in the normal human genome, antisense to Tax deserves serious consideration as a treatment modality for patients whose cells have been demonstrated to harborTax.

Background: Granulomatous slack skin is a rare lymphoproliferative disorder characterized clinically by gradual development of pendulous folds of lax erythematous skin in flexural areas, and histologically by non-necrotizing granuloma, with numerous multinucleated giant cells, mononuclear histiocytes, and atypical lymphocytes associated with loss of elastic fibers. Although there are many reports describing the histological and immunophenotypic features of this disease, only a few have described the ultrastructural features., Methods: Here we report a case of granulomatous slack skin and describe the ultrastructural findings., Results and Conclusion: We could detect some previously not noted abnormal findings in multinucleated giant cells, histiocytes, and atypical lymphocytes.

We present a case of CD56-positive cutaneous lymphoma with a clinical appearance resembling angiosarcoma. The biopsy specimen showed angiocentric infiltrates of small to medium-sized cells positive for CD4, CD45, and CD56 but negative for CD2, surface and cytoplasmic CD3, CD8, CD20, and CD57. There was no detectable clonal rearrangement of either TCRbeta or TCRgamma genes and no dense core granules in the cytoplasm. Epstein-Barr virus was not detected. The patient died of an unrelated disease 20 months after initial biopsy, although there was some response to interleukin-2, radiotherapy, and VP-16. The results suggest that our case does not precisely match the recently proposed variants of CD56-positive lymphoma, namely nasal T/natural killer cell lymphoma and blastic natural killer cell lymphoma. Agranular natural killer cell lymphomas similar to our case in the immunophenotype have been reported to be indolent and occur in the skin. These lymphomas may be a distinct subtype and have a predilection for involving the skin.

Synchronous cutaneous T-cell lymphoma and low-grade B-cell lymphoproliferative disorders have rarely been reported in the same patient. Coexpression of each phenotype in the same lymph node has not, to our knowledge, been previously documented. We describe an 86-year-old man with chronic pruritus and erythroderma and recent-onset peripheral lymphadenopathy and lymphocytosis. Lymph node biopsy provided morphological and immunohistochemical evidence of concurrent small B lymphocytic lymphoma and small pleomorphic T-cell lymphoma. Immunophenotyping of nodal lymphocytes demonstrated two distinct clones: IgM-kappa B-cells with CD5 positivity and CD7 negative T-helper cells. Both immunoglobulin (heavy and light chains) and T-cell receptor (beta I and beta II) gene rearrangements were detected by Southern blot analysis of the lymph node. In contrast, the immunophenotype of lymphocytes from peripheral blood and bone marrow was exclusively that of T-helper cells with atypical CD7 deletion. Electron microscopic examination of circulating lymphocytes revealed small cerebriform Sezary cells. This case demonstrates that small lymphocytic lymphoma may coexist intranodally with cutaneous T-cell lymphoma as a unique form of composite T- and B-cell lymphoma.

We describe a new case of signet ring cell peripheral T cell lymphoma in a 45-year-old man. This lymphoma had a very indolent course, since--without treatment--the clinical staging has shown no evidence of disease progression 11 years after initial symptoms. Immunophenotype indicated pan T antigens (Leu 4 CD3, Leu 1 CD5) and T suppressor cytotoxic antigen (IOT8 CD8) expression. Several T antigens (Leu 5b CD2, Leu 9 CD7, Leu 3a CD4) were not expressed. The proliferation index was less than 5% with Ki 67 monoclonal antibodies. The ultrastructural study showed characteristic cytoplasmic vacuoles containing microvesicles. Five cases of signet ring T cell lymphoma, which were very similar to our case, have been previously described. Their characteristics were primary cutaneous presentation, indolent course, good response to current therapies and a long survival period. The indolent course of these signet ring cell lymphomas may indicate that this type of lymphoma is a low grade malignant lymphoma and not only a morphological pattern.

The concept of skin-associated lymphoid tissue embraces those cells and functions that are integrated in the cutaneous host defense. Recently, it has been possible to identify those circulating T-cells that are skin associated. These cells display the cell-surface phenotype of memory T cells (CD45RO+) and express the cutaneous lymphocyte antigen, a tissue-selective homing receptor involved in directing T-cell traffic to inflamed skin. To investigate the participation of this skin-associated T-cell subset in the pathogenesis of cutaneous T-cell lymphoma, we studied 16 patients with erythrodermic cutaneous T-cell lymphoma for the presence of these surface proteins on circulating cells. Results were compared with eight patients in remission and eight with minimal patch-plaque cutaneous T-cell lymphoma. The mean expression of both CD45RO and cutaneous lymphocyte antigen were significantly greater in the erythrodermic patients than in the other two patient groups. Expression of these markers was shown to be on the cells of the malignant clone by two-color flow cytometry. These results demonstrate that the malignant cells of cutaneous T-cell lymphoma express the markers of skin homing lymphocytes and that their levels are increased in the erythrodermic cutaneous T-cell lymphoma patients. Moreover, the findings suggest a critical role for the skin-selective homing receptor cutaneous lymphocyte antigen in the pathogenesis of cutaneous T-cell lymphoma.

To evaluate whether the expression of T-cell receptor (TCR) V beta families in eight cases of malignant T-cell lymphomas took place in a preferential manner, we analyzed four cases of mycosis fungoides (MF), the most common form of primary cutaneous T-cell non-Hodgkin's lymphomas (NHL), and four cases of primary nodal T-cell NHL. The usage of V beta families in T-cell populations was investigated on mRNA that was transcribed to cDNA using a C beta primer and reverse transcriptase. Subsequently, the specific usage of the families was analyzed by polymerase chain reaction (PCR) using combinations of the selected C beta-oligonucleotide primer and one of the family-specific V beta primers. Peripheral blood lymphocytes from four healthy volunteers and 1 "reactive" lymph node served as a control and expressed all 20 V beta families tested for. In T-cell lines, with restricted V beta expression, and in three patients with advanced MF, only one or two V beta families were expressed at the mRNA level. In an early MF lesion this monoclonal expression was absent: several V beta families were expressed with a weak intensity. This may indicate either a polyclonal origin of MF, or that too few monoclonal neoplastic cells were present in the tissue specimen. In the four nodal T-cell NHL, only one family could be clearly distinguished, whereas some of the other V beta families showed only a weak expression. These latter families represent the reactive T-cell component in the nodal T-cell NHL. Both in nodal T-cell NHL and in MF there was no preferential expression of a particular V beta family. There was a good correlation between PCR data and the expression of V beta-family protein products observed by immunohistochemistry on tissue sections of the T-cell lymphomas. All T-cell lines, three cases of MF, and three cases of nodal T-cell NHL showed a rearrangement of the TCR beta chain on DNA level.

The cutaneous T-cell lymphomas (CTCL) are a group of diseases characterized by malignant proliferations of CD4 positive T-cells having monoclonally rearranged T-cell receptor (TCR) genes. A recent study using monoclonal antibodies to two TCR beta-chain variable (V) region gene products showed preferential expression of the V beta 8 gene product in these tumors. The finding of predominant usage of a single V beta gene would imply that selection by antigen is important in the etiology of these tumors. We have studied eight cases of cutaneous T-cell lymphoma and one cell line derived from a patient with mycosis fungoides/Sezary syndrome, using an extended panel of antibodies to V region gene products. Contrary to the previous report, in our study expression of the V beta 8 gene product by tumor cells was not observed in any of the cases of CTCL or in the tumor cell line studied; preferential use of any of the variable region genes recognized by the antibodies in the panel was not observed.

The cutaneous T-cell lymphomas (CTCLs) comprise a spectrum of non-Hodgkin lymphomas with a predilection for the skin. This heterogeneous group of CTCLs include the prototypic CTCL mycosis fungoides (MF) and the recently described Ki-1+ lymphomas. MF is notoriously difficult to diagnose in its early stages. The histologic appearance of early MF is indistinguishable from that of chronic dermatitis. The limitations of light microscopy in the diagnosis of the CTCLs have led to the development of other diagnostic laboratory techniques. The best approach to the diagnosis of the CTCLs is a multidisciplinary one and should include ultrastructural morphometry, immunophenotyping, immunogenotyping, and histologic evaluation whenever possible. It is the purpose of this overview to point out the strengths and weaknesses of each of these techniques and, together with clinical input, to provide a comprehensive and rational approach to patient care.

Cutaneous multilobated T-cell lymphoma is an uncommon variant of skin-based peripheral T-cell lymphoma typically characterized by cutaneous nodules in elderly patients and a chronic clinical course. We report a case of the disease that led to the patient's death within 2 years after onset. This disease may be associated with a more aggressive clinical course than generally recognized.

We report a case of T cell lymphoma which was exclusively located within the epidermis. The T cells of this lymphoma were all of suppressor-cytotoxic phenotype. They did not express the CD7 antigen and a molecular biology study showed T cell type genotypic rearrangements. Both immunohistochemical and ultrastructural studies showed close contacts between lymphoma and Langerhans cells.

We analyzed immunohistologically the expression of T-cell receptor (TCR)alpha chain on human tonsils and on T-cell lymphoma (T-ML) tissues using the avidin-biotin-peroxidase method. A murine monoclonal antibody alpha F1, specific for the constant region of the TCR alpha chain, was employed. On normal tonsil, alpha F1-positive cells were observed mainly in T-zones and germinal centers. In T-zones, the staining intensities varied markedly, with heavy staining evident in less than one fourth. In germinal centers, a proportion of stained cells showed a histiocytic pattern with small cytoplasmic projections. All the T-ML tissues expressed TCR alpha, whereas the staining intensities varied among cases and among lymphoma cells. No correlations were observed in the expressions of TCR alpha chain and other T-cell markers including CD3, CD4 and CD8.

The supramolecular organization of the keratinocyte cytoskeleton, the basal lamina and of the dermal extracellular matrix in the whole human skin revealed by freeze-deep etching with Pt/C rotary shadowing is presented. The routine equipment for this method and sample preparation are described. The resolution of the method is sufficient to visualize individual cytoskeleton elements and extracellular matrix. The presented cytoskeleton organization is very similar to the meshwork of strands or "microtrabeculae" seen in the cytoplasm of the whole cells by high voltage electron microscopy. Besides, the ultrathin section pattern of epidermis in human skin from patients with mycosis fungoides is described.