Anthony S-Y. Leong

Primary mediastinal embryonal carcinoma in association with Klinefelter's syndrome

Germ cell tumors, particularly those of extragonadal origin, have a rare and only recently recognized association with Klinefelters syndrome. A case of a primary mediastinal embryonal cell carcinoma in a 16‐year‐old male with Klinefelters syndrome is reported.

Node-based t cell lymphoma. the clinical, immunological and morphological spectrum

&NA; Four cases of node‐based T cell lymphoma are presented. The tumours had 2 distinct morphologic patterns. Two cases showed a polymorphous proliferation of pleomorphic lymphoid cells, small lymphocytes, epithelioid cells and arborizing small vessels while the others displayed a monomorphous infiltrate of large atypical lymphoid cells characterized by granular nuclei with numerous tortuous folds to produce a squiggly appearance. One case showed a progression from one histological pattern to the other. Confirmation of the T cell nature of these lymphomas was based on the demonstration of E‐rosette formation by morphologically atypical lymphoid cells which also stained positive for acid alpha‐naphthyl acetate esterase activity. The patients had an average age of 52 yr and presented with a variable distribution of lymphadenopathy and a predominance of extranodal involvement. Two cases disclosed hypergammaglobulinaemia, one of whom had a paraproteinaemia of IgM‐k type. All patients responded poorly to standard combination chemotherapy, 2 expiring 48 and 53 mth after onset of symptoms.

Tracheal paraganglioma: a case report with review of the literature.

Only three cases of tracheal paraganglioma have been reported in the literature. This paper describes an additional case, which showed pharmacological and ultrastructural evidence of hormone secretion. It is suggested that this tumor is derived from true paraganglia located in the trachea and not from misplaced or aberrant paraganglionic tissue. Hemoptysis was the only presenting symptom in two of the four reported cases and significant bleeding occurred during biopsy in the other two cases. The long‐term prognosis appears good if complete resection is possible.

Preferential epidermotropism in adult t-cell leukemia-lymphoma.

Three patients with systemic T-cell leukemia-lymphoma presented with generalized pruritic skin rash which was clinically nondiagnostic. Biopsies revealed infiltration of the superficial dermis by atypical lymphoid cells with epidermal exocytosis (Pautrier abscesses) producing a pattern of histologic involvement indistinguishable from that of mycosis fungoides and Sézary syndrome. This striking similarity suggests that the phenomenon of preferential epidermotropism is not confined to mycosis fungoides and Sézary syndrome, but may be a property shared by other subpopulations of T-lymphocytes.

The role of testicular biopsy in the investigation of male infertility

Summary Sixty‐five testicular biopsies from infertile men were assessed retrospectively. In 21 patients infertility was attributed to varicoceles. In the remaining cases the testicular histology was classified into 3 major groups, normal, hypospermatogenesis and germ cell aplasia. These histological categories were correlated with serum gonadotrophic hormone levels and sperm counts. All cases of germ cell aplasia showed azoospermia or severe oligospermia, but sperm counts alone were not reliable indicators of spermatogenesis. Patients with very low sperm counts and raised levels of serum FSH invariably had germ cell aplasia. These patients made up a group in whom testicular biopsies were of limited value in assessment. In all other instances the testicular biopsy was still an important tool in the assessment and prognostication for fertility in the subfertile male.

The Lymphoid Tissues

The cells of the lymphoid tissues primarily involved in the generation of specific immune responses are the lymphocytes. As well as the lymphocytes, cells of the monocyte-macrophage series, which are collectively called accessory cells (ACs) are essential for generation of both cellular and humoral (antibody) responses. They play a large part in regulating immune responses, by presenting antigen to T and B cells, by degrading antigen and by release of mediators.

Immunological and histochemical techniques in the study of the malignant lymphomas: A review

Summary Current methods of immunological and enzymatic marker studies used in the investigation of the malignant lymphomas are reviewed and the application of such methods is demonstrated by illustrative examples. The reliability of the various techniques and their relevance to a modern diagnostic laboratory are discussed.

B Cell Neoplasia

B cell malignancies are more common than the T cell malignancies and have been recognised for a longer time, although T cells are the initiators and regulators of immune responses. A description of B cell malignancies is needed that includes the most recent classification and relates, as far as possible, to newer insights into basic mechanisms of neoplasms and immunology. The classification of B cell neoplasms, which has been traditionally based on clinical and pathological criteria, is evolving through the use of the battery of monoclonal antibodies now available. The definition during the past decade of molecular markers characteristic of differentiation stages and pathways in normal B cell ontogeny has facilitated a more precise classification.

The pathology of experimental chronic fibrosing pancreatitis–light microscopic and ultrastructural observations

Summary The light microscopic and ultrastructural changes seen in a canine model of chronic fibrosing pancreatitis are described. the distribution of the experimental lesion is similar to that of human chronic obstructive pancreatitis. the canine lesion is also compared to that of human chronic calcifying pancreatitis. It is suggested that the common denominator in all these conditions is an increased pressure in the terminal intercalated ducts which produces pressure atrophy of the acinar cells in the periphery of the obstructed lobules.

Technology of Investigation and Diagnosis

Better understanding of the lymphoid malignancies results largely from the introduction of increasingly precise and sophisticated methods of investigation. Because populations of neoplastic lymphocytes have a very homogeneous marker profile and function, the study of immunological markers has not only provided essential information for the distinction of reactive and neoplastic lymphoid proliferations and the subtyping of lymphocytic leukaemias and non-Hodgkin’s lymphomas, but has also taught us much about lymphoid differentiation.