HUMAN ECCRINE HAMARTOMA OF THE FOREARM ANTEBRACHIAL ORGAN OF THE RINGTAILED LEMUR (LEMUR-CATTA) - A POSSIBLE PHYLOGENETIC RELATIONSHIP

A 31-year-old woman presented with a clinically otherwise unsuspicious area of profuse sweating on her right forearm. Without triggering age nts, sweating attacks producing a clear, serous fluid were observed da ily. Histopathologic examination of a biopsy specimen showed hyperplas tic eccrine glands with pale, stippled cytoplasm characteristic of ecc rine hamartoma. No explanation, however, has been given for the fact t hat several authors observed eccrine hamartomas in the same anatomical location. Adolescent lemurs of the species catta (ringtailed lemur) a re equipped with a pair of antebrachial cutaneous glands located on th e volar sur-face of the wrist. They exude a clear secretion enabling t hem to ''brachial branch mark'' their territories. Histopathologic fin dings in the ringtailed lemur's antebrachial organ show characteristic s of both apocrine and eccrine glands. In contrast to normal apocrine glands, however, the antebrachial organs of ringtailed lemurs reach th e epidermis directly and are not connected to hair follicles. Accordin g to the ''biogenetic law'' of Ernst Haeckel, stating that ontogeny ha s to be seen as a short and incomplete repetition of phylogeny, a huma n fetus passes all evolutional stages from a single cell via amphibian s and mammals to a human being. Thus, the antebrachial organ of the ri ngtailed lemur may be the ''phylogenetic explanation'' for eccrine ham artomas of the forearm in humans. The histopathologic findings of the antebrachial organ and of eccrine hamartomas are in accordance with th is hypothesis.