Significance of Muscularis Mucosae in Metastasis Involvement of Urinary Bladder Transitional Cell Carcinoma
Suchart Chaimuangraj MD*, Charuspong Dissaranan MD*, Charoen Leenanupunth MD*, Prapapan Prathombutr RN**, Panas Chalermsanyakorn MD***
Affiliation : * Urology Division, Department of Surgery, Faculty of Medicine, Ramathibodi Hospital, Mahidol University ** Department of Nursing, Faculty of Medicine, Ramathibodi Hospital, Mahidol University *** Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University
Objective : To assess the significance of muscularis mucosae involvement in metastasis of urinary bladder
transitional cell carcinoma.
Materials and Methods : This was a retrospective cohort study of superficial urothelial carcinoma (transitional
cell carcinoma). Histopathology and patient records of 192 patients were collected from 1990 to 2004. There
were 115 males and 77 females, their age ranged from 43 to 83 years old with an average of 60 + 5 years. One
hundred cases did not invade muscularis mucosae layer (group A) and 92 cases invaded the muscularis
mucosae layer (group B). The histopathology of biopsy or cystectomy specimens for recurrence, progression
of the disease and the number of vessels above and below the muscularis mucosae layer of bladder cancer
specimens were compared by light microscopic examination with Hematoxylin and Eosin (H&E) and
followed by immunoperoxidase desmin stain.
Results : The amount per high power field of the blood and lymphatic vessels below muscularis mucosae layer,
9 (6-12), was significantly higher than that above muscularis mucosae layer, 7 (5-10) (p < 0.05). The cancer
high grade (grade 3) in group B had also significantly higher percentage than that in group A, 30.4:5.0 (p <
0.05). Moreover, the recurrent rate (recurrent > 2) in group B had also a significantly higher percentage than
that in group A, 21.4:4.0 (p < 0.05).
Conclusion : The present study has confirmed previous findings that not all muscularis mucosae layers (about
50%) were found in the biopsy specimens. The findings of superficial urothelial cancer (no invasion to
muscularis propria) invading the muscularis mucosae are a warning sign for invasive tumor that needs more
aggressive treatment.
Keywords : Muscularis mucosae, Urothelial cancer, Transitional cell carcinoma, Recurrence, Urinary bladder
