[From Hashimoto thyroiditis to B-cell lymphoma of the thyroid gland]. / Von der Hashimoto-Thyreoiditis zum B-Zell-Lymphom der Schilddrüse.

Lymphoma of the thyroid gland is an uncommon condition occurring primarily in older women. Most patients have a short history of an enlarging thyroid or a neck mass causing tracheal compression. There is also a strong association between thyroid lymphoma and Hashimoto's thyroiditis. The diagnosis is established by biopsy. The conventional approach to treatment is combination of radiation therapy with multi-agent chemotherapy, while there is no significant role for extirpative surgery in the management of thyroid lymphoma. The prognosis of localised tumours (stage IE, Ann Arbor classification) is excellent. Extrathyroidal involvement (stage IIE-IVE) reduces the 5-year survival rate to about 70%, provided that current therapy regimens are respected. In this case report, the different stages of development from Hashimoto's thyroiditis to thyroid lymphoma are demonstrated by histology. In a review of the literature we discuss the diagnostic procedure and the current approach to treatment.

Molecular epidemiology of Mycobacterium tuberculosis strains isolated from patients in a human immunodeficiency virus cohort in Switzerland.

From 1989 to 1995, 46 patients infected with the human immunodeficiency virus were diagnosed with tuberculosis at the University Hospital in Zurich. Using the IS6110 insertion sequence as a genetic marker, restriction fragment length polymorphism analyses were done for 52 Mycobacterium tuberculosis isolates. We have found a large degree of IS6110 polymorphism, ranging from 1 to 16 copies. For isolates from patients from whom multiple isolates had been available, the IS6110 pattern remained virtually stable over a period of up to 4 years, as well as during emerging drug resistance. In none of the cases was a reinfection of a patient with another strain detected. For isolates from 10 patients we detected identical patterns which could be associated with four clusters. In one of these, the strains exhibited a low IS6110 copy number (four bands), and the strains were further analyzed by hybridizing with (i) the polymorphic GC-rich repetitive sequence (PGRS) and (ii) the 36-bp direct-repeat (DR) cluster sequence. One of these isolates had a different pattern with the PGRS as well as with the DR sequence and could therefore be safely excluded from that cluster. These findings point to the importance of applying more than one genetic criterion in the molecular biological study of strain relatedness.