The surgical pathology of ainhum (dactylolysis spontanea).

Ainhum (dactylolysis spontanea) is a poorly understood disease characterized by spontaneous autoamputation of the fifth toe. Its incidence is highest among blacks and in the tropical and subtropical climates. The present study is the first to present certain gross and semimicroscopic findings. Moreover, scanning electron microscopic and histochemical data are presented and these reportings are believed to be unique. Hyperkeratosis and parakeratosis, together with elongation of the epidermal rete pegs and acanthosis, are observed and these findings are associated with the presence of numerous fibroblasts and wound repair phenomena. The leukocytic infiltrate is identified as being principally of T lymphocyte type, suggesting the existence of an unknown immunologic response. Relevant intraoperative data, radiographs, and light microscopy, as well as transmission electron microscopy, have been reported in this study. The spontaneous amputation of the fifth toe, designated as dactylolysis spontanea, has no known etiology, and no treatment short of amputation. The worldwide incidence of this condition is rare. Two cases have been observed at the Baltimore Veterans Administration Medical Center in the last 5 years. One patient is in an early stage of the disease. The present study involves the single instance in which amputation was elected as the treatment of choice. Because the occurrence of ainhum (dactylolysis spontanea) is rare, discussion of the disease is lacking in medical literature. It is the intent of the present study to be the definitive analysis of clinical, surgical, and surgical-pathologic data of this rare disease. Unique applications of semimicroscopic, histochemical, and light microscopic findings, as well as transmission and electron microscopy, will be presented. Speculation as to the implications of immunologic and/or wound repair responses as implicated in ainhum needs to be explored.