[Hypopituitarism and hematological abnormalities mimicking myelodysplastic syndrome. Report of four cases]

Insufficiency of the pituitary gland and hematological abnormalities may coexist in the context of two syndromes. In the course of some hematopoietic neoplasms, particularly acute leukemias, the pituitary insufficiency may be caused by destruction of the gland either by direct neoplastic infiltration or occlusion of vessels. Alternatively, thy pituitary dysfunction may be associated with but not caused by hematological abnormalities, usually mild peripheral cytopenias. We present four cases of the latter type (1. M/33, pituitary tumor, hypogonadism, hyperprolactinemia, anemia, mild leukopenia with leukocytosis, 2. F/54, pituitary tumor, hyperprolactinemia, thyreotropic and corticotropic insufficiency, anemia, thrombocytopenia, mild neutropenia, 3. F/27, pituitary tumor, diabetes insipidus, hypogonadism, sideropenic anemia, leukopenia, thrombocytopenia, 4. M/24, primary multihormonal insufficiency of the anterior portion of the pituitary gland, neutropenia, microcytosis). Trephine and aspiration bone marrow biopsies revealed topographic and cytological abnormalities partially resembling these found in myelodysplastic syndromes (MDS). Bone marrow cellularity varied markedly between and within the cases, and in three patients abnormal aplastic areas were found. The percentage of hematopoietic stem cells (CD34+) was low in three cases and normal in one case. Pituitary dysfunction may be associated with hematological abnormalities simulating MDS, but showing different, less aggressive clinical course. The proliferative potential of hematopoietic cells is low, the peripheral blood abnormalities are stable, and no patient developed acute leukemia. Detailed bone marrow examination, including the trephine bone marrow biopsy, is useful in differentiation with true MDS, which was also reported in the literature in the patients with pituitary insufficiency.