891 



(in cross sections generally smaller than 20 ix, only Ribbert found 

 some bigger tibres up to 80 ft) ; here however the fibres are generally 

 enlarged, some of them even reach a diameter of 300 it. 



Secondly one sees in rhabdomyoma thai the small muscle-fibres 

 have a very defective structure ; frequently they can hardly be 

 recognised ; a rhabdomyoma of a fish published by Fiebiger ^) showed 

 just as well very small elements which could scarcely be identified 

 with muscle-fibres. 



In our case however the small fibres have generally a normal 

 structure, whilst the abnormities appear in the big fibres. Further 

 we see that the arrangement of the septa of fibrous-tissue resembles 

 for the greater part the normal conditions; we do not see here a 

 capricious grouping of the muscle-fibres, as can be expected in 

 tumours, and finally we see that hypertrophic fibres also occur in 

 the normal muscle-tissue that surrounds the knob. From these 

 observations I conclude that in this case we have not to do with a 

 new grown tissue which to a certain extent carries on an independent 

 existence, but with a tissue that has grown by hypertrophy and 

 abnormal proliferation of muscle-fibres which were already locally 

 present. 



Such a local proliferation of striped muscle-fibres looking like a 

 tumour is very uncommon. 



In the literature I could only find one similar case: Lorenz ') 

 described a "geschwulstartige Hypertrophie" in the musculus glutaeus 

 maximus of a man 52 years old, which has g»'own after "Ueberan- 

 strengung". 



Here he found very big muscle-fibres even 100 (i and 200 ft in 

 transverse section. The fibrils were coarser than normal, the transverse 

 striation was less distinct, in longitudinal sections he saw many 

 divisions of muscle-fibres; divers fibres showed degeneration. ("Zenker" 

 degeneration and "fibrillaire Zerklüftung"). 



The nuclei of the sarcolemma had not augmented, signs of 

 inflammation were not present. 



The case of Lorenz rather resembles ours ; as for the etiology it 

 does not teach us anything. 



Neither in our case could I find the cause of this abnormal 

 proliferation : bacteria, protozoa and other parasites were not to be 

 found, evident signs of inflammation could not be discerned, the peri- 



^) J. Fiebiger : Ein Rhabdomyom bei einem Kabljau. Zeitschr. f. Krebsforschung 

 Bd. 7. S. 382. 



») Handb. der spec. Pathol, u. Therapie (Nothnagel) Bd. XI. S. 415. 1904. 



