Subungual Squamous Cell Carcinoma

From Felipedia

Subungual tumour in a dog

Same subungual tumour excised after amputation

Xray of above tumour showing distortion of metacarpal bones

Subungual squamous cell carcinoma (nailbed squamous cell carcimona) is a malignant tumor of the nailbed epithelium in cats, which shows varying degrees of keratinocyte (squamous cell) differentiation.

Tumors that effect the subungual region of the cat are most likely metastatic pulmonary carcinomas and not squamous cell carcinomas, which are extremely rare in the cat.

Histology

• Identical to those described for squamous cell carcinoma
• Many are well differentiated
• Due to its location, it is invasive and there is destruction of the phalangeal bones
• Invasion and destruction of the third phalanx and occasionally the articular cartilage, with extension into the joint space and invasion of the second phalanx
• Best identified by radiographic examination of the digit
• Multiple digits may be affected
• Secondary inflammation is common