Tylosis and Oesophageal Carcinoma

structure of the epidermis of those areas of skin subject to tylosis, and we suggest that both tissues may be responsive to the same functional requirement-namely, the need to provide resistance to mechanical friction. Human epidermis can be classified into "thick" and "thin" types.3 Thick skin is found most characteristically on the palms and soles, and relative to thin skin it has a thicker stratum corneum, a more marked stratum granulosum, and a thick stratum spinosum. It also has a stratum lucidum (Fig. 1), a layer not found in thin skin, and is devoid of hair follicles. In sections of skin from the middle finger of a female cadaver it was noted that the histological appearances overlying the metacarpophalangeal and proximal and distal interphalangeal joints and distal phalanx were those of thick skin, as judged by their conformity with the features described above. The distribution