The Collaborative International Dictionary of English v.0.48:

Scirrhus \Scir"rhus\, n.; pl. L. Scirrhi, E. Scirrhuses.
   [NL., from L. scirros, Gr. ?, ?, fr. ?, ?, hard.] (Med.)
   (a) An indurated organ or part; especially, an indurated
       gland. [Obs.]
   (b) A cancerous tumor which is hard, translucent, of a gray
       or bluish color, and emits a creaking sound when incised.
       [Sometimes incorrectly written schirrus; written also
       skirrhus.]
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Skirrhus \Skir"rhus\, n. (Med.)
   See Scirrhus.
   [1913 Webster]