Prognosis in occult thymomas in myasthenia gravis following transcervical thymectomy
A. E. Papatestas, J. Pozner, G. Genkins, P. Kornfeld and R. J. Matta
Department of Surgery, Mount Sinai Medical Center, New York, NY 10029.
Thymomas were noted in 239 (11%) of 2097 myasthenic patients followed up at
our institution. Among 996 patients who had undergone thymectomy, 191
patients (19%) had thymomas compared with 48 (4%) of 1101 patients treated
without surgery. A definitive diagnosis of thymoma was not made until after
thymectomy in 61 patients (35%); in patients not treated with thymectomy,
23% of associated tumors were diagnosed at autopsy. Patients with occult
thymomas treated with the transcervical approach had a clinical course
superior to those with tumors diagnosed prior to surgery and treated with
the transsternal approach. Most of the advantage could be attributed to the
association of occult thymomas with small tumor size and to the association
of the latter with absence of invasiveness. Small tumor size was
significantly associated with higher remission and lower mortality as shown
in a proportional hazards analysis. Occult thymomas were accessible through
the transcervical approach, with some operations necessitating a
complementary mediastinotomy. Thymectomy, through the transcervical
approach if technically feasible, is of benefit to all patients, has
minimal morbidity, and should be performed early in the course of the
disease as a diagnostic and therapeutic intervention since the risk of
occult thymomas in patients with myasthenia gravis is high.
