Keratoacanthoma is a malignant tumor that is rarely located in the subungual region, but which has a tendency to recur. Spontaneous regression of these lesions in the nail apparatus region almost never occurs, and a differential diagnosis with other neoplasias, particularly squamous cell carcinoma, is essential. The authors present the case of a man with a diagnosis of subungual keratoacanthoma, which responded well to surgical treatment and had a favorable development.

Keywords: NAILS; KERATOACANTHOMA; FINGER FALANGES.

INTRODUCTION: Onychomatricoma is a rare benign tumor characterized by a clinical tetrad of a yellowish longitudinal band of varying thickness, splinter hemorrhages, longitudinal and transverse hypercurvature of the nail plate, and digitiform projections emerging from the nail matrix, leaving cavitations in the nail plate. We report a case of a female patient, 49 years old, with a history of a tumoral lesion in the third left toe for about four years, with a progressive increase in this period. Physical examination revealed an exuberant tumor lesion clinically compatible with onychomatricoma, confirmed by pathological examination after complete tumor excision.

Keywords: Nails; Nail diseases; Neoplasms

Retronychia is an inflammatory onychopathy characterized by the disordered growth and stacking of nail plates, associated with an imbalance in the matrix production of plaques, which tend to overlap. This condition may be associated with trauma, evolving with an inflammatory reaction along the proximal nail fold and granulation tissue formation. We report the case of a patient with retronychia in the left hallux, submitted to surgical treatment after failure of therapeutic responses with previous clinical treatments. The surgical approach led to the avulsion of the overlapping nail plates and the excision of voluminous granulation tissues, achieving adequate postoperative evolution.

Keywords: Nail diseases; Nails; Nails ingrown

Onychocryptosis is a frequent nail disease, which most commonly affects the toes. It has some variants, including the little known "Harpoon Nail". The diagnosis is usually clinical, and the treatment is surgical, with different techniques described in the literature. We report the case of a 25-year-old man with a harpoon nail on the left hallux and the surgical method used for treatment with excellent results

Keywords: Nail diseases; Nails ingrown; Hallux