Follicular and diffuse mixed small-cleaved and large-cell lymphoma--a clinicopathologic study

The clinical records and initial biopsy materials from 76 patients with mixed small-cleaved and large-cell lymphoma containing both a follicular and diffuse architectural pattern were reviewed. The characteristics of this group, treated at Stanford University Medical Center (SUMC) between 1963 and 1983, are described. The 5-year actuarial survival and freedom from progression are 70% and 27.5%, respectively. Classification according to the degree of follicularity indicated that patients with focally follicular areas (ie, less than 25% of the histologic section) have a significantly worse freedom from progression and overall survival at 5 years compared with those patients with a predominantly follicular architecture (ie, greater than 50% follicular areas). Based on our analysis, we feel that the degree of follicularity is an important prognostic factor and that mixed lymphoma patients with only focally follicular areas behave more like an intermediate-grade lymphoma and should be treated aggressively.

Clonal rearrangements of T-cell receptor genes in mycosis fungoides and dermatopathic lymphadenopathy

Histologic diagnosis of mycosis fungoides may be difficult, especially in lymph nodes that show changes frequently associated with chronic skin disease. As an alternative approach to diagnosis, we have analyzed the configuration of DNA for the beta T-cell receptor genes in biopsy tissues from 14 patients with mycosis fungoides. Clonal rearrangements of these genes were found in each specimen tht contained histologically unambiguous mycosis fungoides. Clonal rearrangements were also found in seven of nine lymph nodes removed from patients with mycosis fungoides and considered histologically to contain only benign lymphadenopathy. Matching rearrangements of beta T-cell receptor genes were detected in benign lymph nodes and histologically involved tissues when paired specimens were available from the same cases. Our findings provide molecular evidence for the clonal T-cell origin of mycosis fungoides and indicate the high incidence of extracutaneous disease in patients with palpable lymphadenopathy. In addition, this study demonstrates that the detection of rearranged T-cell receptor genes can be a sensitive and practical method for the diagnosis and characterization of T-cell neoplasms.

Gastrointestinal lymphomas. Immunohistochemical studies on the cell of origin

The classification of primary malignant lymphomas of the gastrointestinal tract by their cell of origin has been a subject of great controversy in recent years, with the proportion of histologic subtypes varying substantially in different published series. Much of this controversy was initially due to the widely recognized inherent difficulty of classifying lymphomas based on routine histologic sections alone. However, the advent of immunohistochemical techniques has also yielded disparate results. Particularly contentious has been the notion of true histiocytic lymphomas, which some investigators have claimed to be relatively frequent in the gastrointestinal tract, whereas others doubt whether they exist at all. We present here a classification of 25 gastrointestinal lymphomas seen in the surgical pathology services of UCLA Hospital and Stanford University Medical Center. Unlike all previously reported series, we have utilized frozen tissue sections for the performance of immunohistochemical studies, which we and others have found to be far more reliable than the use of formalin-fixed, paraffin-embedded tissues, particularly in detecting monoclonal surface staining of immunoglobulin light- and heavy-chain markers. We find that this technique lessens the likelihood of overinterpreting the stains for histiocyte markers (alpha 1-antitrypsin and lysozyme), which are often difficult to read owing to strong positive staining of benign reactive histiocytes within the tumor. Utilizing these techniques, we have been able to classify definitely 21 of our 25 lymphomas (84%) as of B-cell origin, whereas none appeared to be histiocytic. We conclude that true histiocytic lymphomas of the gastrointestinal tract must be very rare, and we recommend the routine use of frozen tissue sections for more accurate classification of these interesting lesions.

Pharmacokinetics of intraarterial mitomycin C in humans

The pharmacological advantage of mitomycin C (MMC) given by intraarterial infusion as compared to i.v. infusion was studied in seven patients with cancer metastatic to the liver. Hepatic artery, hepatic vein, and peripheral vein catheters were placed, and then each patient received constant infusions of MMC via the intraarterial and peripheral i.v. routes at 0.4, 1.2, and 4.0 mg/sq m/hr. MMC concentrations were measured in the hepatic artery, hepatic vein, and a peripheral vein by high-pressure liquid chromatography after steady state had been reached at 2 hr. Mean plasma clearance increased significantly with infusion rate from 0.6 liter/min at 0.4 mg/sq m/hr to 1.1 liters/min at 4.0 mg/sq m/hr. The calculated relative advantage of treating hepatic tumors via the intraarterial route (Rt) was found to be 2.5- to 3.6-fold at a plasma flow rate of 0.4 liter/sq m and MMC infusion rates of 0.4 to 4.0 mg/sq m/hr. The hepatic vein MMC concentration averaged 30% higher during intraarterial than during i.v. infusion. Hepatic extraction of MMC averaged only 23%, so that the intraarterial route offered little advantage with respect to reduced systemic toxicity. These data suggest a limited pharmacological rationale for the selection of the intraarterial route for the treatment of hepatic tumors with MMC.