[Development of sarcoma on a ectopic extramedullary hematopoiesis secondary to hereditary spherocytosis: Case report and literature review]. / Développement d'un sarcome sur foyer ectopique hématopoïétique secondaire à une sphérocytose héréditaire : à propos d'un cas et revue de la littérature.

INTRODUCTION: Extramedullary hematopoiesis is a complication of myeloproliferative neoplasms or of chronic hemolysis. The more frequent localizations are splenic, ganglionic or paraspinal. Rarely, extramedullary hematopoiesis is associated with solid cancer. CASE REPORT: We report an original case of sarcoma located in an extramedullary hematopoiesis mass in a 72-year-old woman suffering from hereditary spherocytosis. An asymptomatic right paravertebral mass was found in 2004; the biopsy confirmed extramedullary hematopoiesis. In 2016, the patient was hospitalized due to paravertebral pain. Computed tomography showed the extension of the right paraspinal mass to pleura and mediastinum as well as vertebral bone lysis. Positron emission tomography showed an intense hypermetabolism. The biopsy showed undifferentiated sarcoma. CONCLUSION: This case report illustrates the risk of neoplastic transformation of extramedullary hematopoiesis, and the need for a biopsy when confronted to atypical aspect.

[Renal extramedullary hematopoietic tumor revealing a hereditary spherocytosis in an adult patient]. / Révélation à l'âge adulte d'une sphérocytose héréditaire devant une tumeur rénale: forme frontière entre myélolipome et foyer d'hématopoïèse extra-médullaire.

INTRODUCTION: Myelolipomas and extramedullary hematopoietic tumors are uncommon benign tumors. They are variably composed of mature adipose tissue and hematopoietic tissue. Myelolipoma is usually observed in the adrenal gland and extramedullary hematopoietic tumors in the liver and spleen but may occasionally be found within solid tumors. CASE REPORT: A 62-year-old man without previous haematological history presented with a voluminous solitary bilateral renal tumor. Contrast-enhanced ultrasound CT-scan and scintigraphy with technetium-99m-nanocolloid and indium-111-chloride bone marrow were highly suggestive of extramedullary hematopoietic tumor. CT-guided biopsy suggested a diagnosis of myelolipoma. An atypical hereditary spherocytosis, undiagnosed until now, was demonstrated. CONCLUSION: We report, for the first time to our knowledge, a border form between extramedullary hematopoiesis tumor and myelolipoma of renal localisation revealing a hereditary spherocytosis in an adult patient.