[Idiopathic myelofibrosis with extramedullary hematopoiesis foci in the skin and testicles. Report of a case]. / Mielofibrosis idiopática con focos de hematopoyesis extramedular en piel y testículo. Presentación de un caso.

Idiopathic myelofibrosis (IMF) is a clonal chronic myeloproliferative syndrome characterized by the proliferation of the three haemopoietic series and the marrow connective tissue and by the development of extramedullary haemopoiesis in the liver, spleen and lymph nodes. Cutaneous extramedullary haemopoiesis is an uncommon event and we could not find any reported cases of testicular involvement in this disease. We report the case of a 28 year-old male with diagnosis of idiopathic myelofibrosis in November 1988. During the course of the disease, three years later, he developed a tumor on his right testis. Histologic examination showed extramedullary haemopoiesis with cells of the myeloid, erythroid and megakaryocyte series, in the interstice. Eight months later, numerous red-purple papules and nodules developed on the patients's trunk. The biopsy of a skin lesion revealed an infiltration of the dermis by myeloid, erythroid cells and few megakaryocytes. The patient's clinical condition worsened, and he died in February 1993 following progressive deterioration of the general condition. We describe a case of IFM with extramedullary hemopoiesis involving the skin and the testis pointing out the rarity of these localization.