Cytology of the mycosis fungoides and the Sézary syndrome. Correlation between light and electron microscopy

Extracellular multivesicular bodies in tissues affected by inflammation/repair and tumors

Extracellular vesicles (EVs) are a heterogeneous population involved in intercellular communication. Little attention has been paid to a peculiar EV type with the appearance of a multivesicular body: extracellular multivesicular body (EMVB), also termed matrix vesicle cluster/multivesicular cargo. The aim of this work is to assess the ultrastructural characteristics, participation, and tissue location of EMVBs in inflammation/repair and tumors (with physiopathological processes involving intense intercellular communication), for which representative specimens were used. The results showed several forms of EMVBs: a) mature EMVBs, made up of clusters of vesicles surrounded by a plasma membrane, b) pre-EMVBs, with protruding grouped vesicles under the cell membrane, and c) post-EMVBs, releasing their vesicles. In tissues with inflammation/repair, EMVBs were observed in vessel lumens, interstitial spaces of vessel walls (between endothelial cells, pericytes, and smooth muscle cells) and between inflammatory and stromal cells. In tumors, such as basal cell carcinoma, craniopharyngioma, syringocystoadenoma, fibrous histiocytoma, alveolar rhabdomyosarcoma, lymphomas, neuroblastoma, astrocytomas, meningiomas, and hydatiform mole, EMVBs were present in tumor gland lumens and between tumor cells. In conclusion, in numerous physiopathological processes, we contribute EMVB ultrastructural characteristics (including different forms of mature, pre- and post-EMVBs, suggesting a more efficient EV transport), location and relationship with different types of cells. Further studies are required to assess the role of EMVBs in these physiopathological conditions.

Cutaneous T-cell lymphoma: a review

Cutaneous T-cell lymphomas define a spectrum of disorders associated with T-lymphocytic proliferation with clinical manifestations occurring in the skin during the course of the disease. This review has dealt with two rather uncommon disorders, namely mycosis fungoides and Sezary syndrome which are indolent malignant lymphomas, occurring primarily in the fifth decade, and affecting males most frequently. Historically, mycosis fungoides and Sezary syndrome have been described for a relatively short time. As witnessed by Table 2, little was known concerning these disorders, other than clinical and pathologic features, until the application of immunologic, cell biologic, and cytogenetic technology which burgeoned a multitude of questions. The discovery of TCGF has allowed for both continuous growth of normal and neoplastic T cells and for the clonal expansion of some malignant clones. The establishment of these continuous cultures allowed for: (1) investigation of the mechanism of TCGF production and stimulation of T-cell growth, and (2) identification of HTLV, a retrovirus found in cell cultures from two patients with CTCL, and subsequently from patients with Japanese adult T-cell lymphoma. In addition, the HTLV has been related to a more virulent form of T-cell malignancy. The exact etiologic role of this virus in the CTCL is presently the subject of intense investigation. Through the use of immunologic methods the malignant cell of CTCL has been pheno-typically and functionally characterized as a "helper/inducer" subtype (E rosette+, anti-T-cell antisera+, T11+, T1+, T3+, 3A1-, T6-, T8-) and usually Ia-, HLADR-. Clinical manifestations of the phenotype may be clinically apparent in the serologic abnormalities present in these disorders. Utilizing these methods to investigate these disorders may provide a key to the understanding of T-cell function and cellular immunity much as myeloma provided a model for the understanding of B cells and immunity. Clinically and pathologically, these disorders behave as malignant indolent lymphomas with spread from localized cutaneous lesions to extracutaneous involvement of the blood, lymph nodes, and viscera culminating in the death of the patient from either organ dysfunction or infectious complications. At autopsy, this extracutaneous involvement is more pronounced than what was expected ante-mortem. Application of prospective staging techniques employing such special procedures as E-rosette cytology, cytogenetics, and electron microscopy in addition to usual light microscopy studies has demonstrated a greater percentage of extracutaneous involvement than otherwise expected.(ABSTRACT TRUNCATED AT 400 WORDS)

Prognostic significance of cytomorphology in the cutaneous T-cell lymphomas

In this retrospective study, the degree of differentiation of atypical lymphoid cells was assessed in pretreatment cutaneous biopsy specimens from 248 patients with cutaneous T-cell lymphomas (mycosis fungoides and Sézary syndrome) and the findings were correlated with the subsequent therapeutic results. Overall, patients with a predominance of cells with hyperchromatic nuclei (well-differentiated lymphoid cells) in cutaneous infiltrates responded better to treatment with improved survival rates than patients with infiltrates composed predominantly of cells with pale vascular nuclei (poorly differentiated lymphoid cells). Infiltrates with a predominance of poorly differentiated lymphoid cells were observed primarily in patients with advanced (tumor) stages of disease. However, comparison of the therapeutic results achieved for the two cytomorphologic patterns in patients at comparable stages of advanced disease did not reveal significant differences, indicating that the presence of poorly differentiated cells in large proportions does not have additional prognostic implications beyond those obtained from usual staging procedures. We speculate that the atypical cells with large, pale vesicular nuclei found in lesions of cutaneous T-cell lymphoma are not a more malignant cell population but rather evolve from more hyperchromatic cellular forms, perhaps a byproduct of malignant dedifferentiation.

Histological features of "pagetoid reticulosis" (Woringer-Kolopp) in pre-mycosis fungoides

The case of a 66-year-old female with chronic skin lesions is described, which clinically resembled parakeratosis variegata but histologically showed the pattern of "pagetoid reticulosis" (Woringer-Kolopp). The intraepidermal pagetoid cells were lymphoid cells which, by electron microscopy, could be identified as small Sézary cells. The intraepidermal presence of numerous atypical reticulum cells does not support the theory of "pagetoid reticulosis" as a separate nosological entity, but rather stresses the epidermotropic character of (pre-)mycosis fungoides just known from intraepidermal Pautrier microabscesses.

Oral methoxsalen photochemotherapy of mycosis fungoides

The cutaneous manifestations of mycosis fungoides have been successfully treated in nine patients for 16 to 28 months with oral methoxsalen and subsequent irradiation with longwave ultraviolet light. The efficacy of this therapy was confirmed in one patient, who showed complete clearing of generalized plaques after 1 month (12 treatments) except for a shielded control area which worsened during this period. Methoxsalen photochemotherapy may prove a valuable addition to therapies currently available for mycosis fungoides and may obviate some of the problems associated with conventional management of this disorder.