Association of expression of CD44v6 with systemic anaplastic large cell lymphoma: comparison with primary cutaneous anaplastic large cell lymphoma.

CD44 is a ubiquitous multifunctional cell surface adhesion molecule family. High expression of the standard form, CD44s (CD44), and its variant form, CD44v6, has been reported to be associated with tumor dissemination in non-Hodgkin lymphoma. To evaluate the potential role of CD44 and/or CD44v6 in different entities of anaplastic large cell lymphoma (ALCL), 30 cases of systemic ALCL (sALCL; 20 cases) and primary cutaneous ALCL (cALCL; 10 cases) were compared for expression of CD44 and CD44v6 by immunohistochemical staining. Expression of CD44v6 also was analyzed with respect to expression of anaplastic lymphoma kinase (ALK) in sALCL. No difference of CD44 expression was noted between sALCL and cALCL In contrast, expression of CD44v6 was found in 18 (90%) of sALCL cases and in 5 (50%) of cALCL cases. There was no correlation between expression of CD44v6 and expression of ALK in sALCL. These results indicate that expression of CD44v6 rather than CD44 correlates with sALCL. Furthermore, these results suggest that CD44v6 and ALK may be independent predictors of risk for the systemic phenotype of ALCL.

Large anaplastic cell Ki-1 positive malignant lymphoma with peculiar endocytotic vacuoles.

Unusual intracytoplasmic inclusions are occasionally seen in some variants of malignant lymphoma. We report here a case of large anaplastic cell malignant lymphoma with peculiar vacuoles of probable endocytotic origin. Immunological findings demonstrated the characteristics of activated cells typical of a large anaplastic cell Ki-1 positive lymphoma. The tumour cells exhibited a phenotype of peripheral helper-inducer T-cells. The intracytoplasmic vacuoles were positive with the T surface marker antibodies. Ultrastructurally, these inclusions were closely related to the microvesicle-containing vacuoles reported in signet ring cell lymphomas of B or T cell lineage. The mechanism of cytoplasmic vacuole formation is discussed. An endocytotic origin is possible. The resemblance to the "capping" phenomenon in small lymphocytes is stressed.

Antibodies as diagnostic probes in the identification of anaplastic round cell malignancy.

The introduction of hybridoma technology has rapidly expanded the role of immunohistochemical analysis in identification of anaplastic malignancy. High affinity antibodies now allow the detection of a wide range of tissue specific antigens so that anaplastic tumours can be accurately classified without the need for costly and often unrewarding, time-consuming ancillary investigations such as electron microscopy, cell culture and chromosomal studies. This review examines the application of a selected panel of commercially available antibodies of proven specificity for the diagnosis of anaplastic round cell tumours. Details of specific examples are provided to illustrate the role of such tissue specific antibodies as diagnostic probes and the approach to anaplastic tumours in various sites is discussed.

[Prognostic significance of lymphocytes forming "active rosettes" in lung cancer]. / Intérêt pronostique des lymphocytes formant des "rosettes actives" dans le cancer du poumon.

Lymphocytes forming E rosettes, active E, autologous and EA antibodies were studied in 66 subjects (56 men, 10 women, mean age 59, range: 40-85 years) who presented with lung cancer classified on the TMN scale in stages I and II: 19; stage III: 20; stage IV: 27. In comparison to the controls, there was a significant reduction (p less than 0.01) in E, autologous and EA rosettes in the patients. A reduction in E active rosettes (compared to controls) was noted for stage IV cases (p less than 0.01) and rose with the stage. The formation of rosettes was reduced in 50 squamous carcinomas compared to 12 anaplastic carcinomas for E rosettes (p less than 0.01) and E active (p less than 0.02). If one compares the actuarial survival curves of 37 patients with E act rosettes greater than or equal to 23% and of 29 with a level of less than 23%, the mean survival for all stages combined was 14.1 months in the first group and 8.2 months in the second group. Associated with an extension of the tumour, the immunological system has a role in determining outcome and lymphocytes forming active E rosettes appear to be the subpopulation most closely correlated with survival.

Anaplasia rediviva.

Anaplasia refers to the apparent retrogression toward an embryonic state that occurs in some human and animal tumors, the consequence, presumably, of a derepression of genes that would normally have been switched off in the course of development. The fetal substances newly formed in tumors are identified immunologically and are therefore referred to as "antigens." Some such antigens, for example, carcinoembryonic antigen and alpha-fetoprotein, and blood-group precursor substances have great promise diagnostically but play no known part in resistance to malignant growth. The reawakened fetal antigens that are of special interest and importance are those that are capable of arousing cell-mediated immunity and thus may contribute to antitumor immunity. Modern research, therefore, rehabilitates an etiologc notion earlier thought to have been discredited.