Haematoxylin and eosin section of the tumor showing intersecting fascicles of cytologically benign smooth muscle cells (a) that are positive for actin (b) and h-caldesom (c). A Chinese family with diffuse oesophageal leiomyomatosis: a new COL4A5/COL4A6 deletion and a case of gonosomal mosaicism: Liu W, Wong JK, He Q, Wong EH, Tang CS, Zhang R, So MT, Wong KK, Nicholls J, Cherny SS, Sham PC, Tam PK, Garcia-Barcelo MM, Xia H - BMC medical genetics (2015). Not altered. CC.