Paroxysmal nocturnal hemoglobinuria clone was detected in 20/152 patients. Negative population's percentages were high in patients with classic PNH, Hematimetry, LAP and adequate use of CF contribute to PNH clone detection in the laboratory.

Our results suggest that diagnosis of immune Np in the laboratory may be improved by focusing on patient's PMN together with the assessment of cellular markers.

Background The success of complex molecular cytogenetic studies depends on having properly spread chromosomes. However, inconsistency of optimum chromosome spreading remains a major problem in cytogenetic studies. Methods The metaphase spreading process was carefully timed to identify the most critical phase of chromosome spreading. The effects of dropping height of cell suspension, slide condition, drying time, fixative ratio, and relative humidity on the quality of metaphase spreads were studied by quantitative examination of metaphase chromosome spreads. Normal and immortalized human epithelial ovarian cells, neuroblastoma cells, and normal lymphocytes were tested. Results Humidity over the slide was the most important variable affecting the quality of chromosome spreads. Consistent improvement in chromosome spreading (larger metaphase area, less chromosome overlaps, or lower frequencies of broken metaphases) was obtained for all cell types if dynamic cell rehydration, occurring as fixative absorbs moisture from air, was made to coincide with the prompt fixation of spread chromosomes to the slide. This was achieved by dropping cells on dry glass slides placed in a shallow metal tray and then quickly lowering the tray into a covered 50°C water bath for slide drying. Conclusions A new and simple method for improving metaphase chromosome spreading was developed based on our study on the characteristics of chromosome spreading. Cytometry Part A 51A:46–51, 2003. © 2002 Wiley‐Liss, Inc.

FL 33612 to permit rapid consideration for publication. Primary Granulocytic Sarcoma of the Nasopharynx To the Editor: Granulocytic sarcomas (GS) or chloromas are solid masses of myeloid leukemia cells. The most common sites include the female reproductive tract, breast, skin, gut, and testis [1]. Most cases are secondary to systemic leukemia or represent disease progression in acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), or chronic myeloid leukemia (CML). An increasing incidence of GS has also been observed after allogeneic bone marrow transplantation for AML and CML [2]. Primary GS is a rare disease and can cause diagnostic pitfalls, especially for disease at uncommon sites and without concomitant marrow involvement. We present the first case of isolated primary GS in the nasopharynx (NP). A 37-year-old Chinese man presented with serous otitis media of the right ear and myringotomy and grommet insertion was performed. Random nasopharynx (NP) biopsies for suspected nasopharyngeal carcinoma (NPC) showed only nonspecific inflammation. Two months later, he presented again with bloodstained post-nasal drip and left ear conductive deafness. A magnetic resonance imaging (MRI) showed NP infiltration (Fig. 1a), with no other lesions in the thorax, abdomen, or pelvis. A repeat examination showed inflamed and irregular mucosa. A biopsy showed submucosal invasion by sheets of myeloid blast cells (Fig. 1b), positive for CD45 and myeloperoxidase and negative for CD20 and CD3. The blasts did not express CD56, a natural killer cell marker associated with GS. A bone marrow biopsy was normal and molecular testing for the AML1/ETO gene fusion was negative (data not shown). Examination of the cerebrospinal fluid (CSF) was normal. He was treated as standard risk AML, with 7+3 induction chemotherapy [cytosine arabinoside (Ara-C) 100 mg/m 2 × 7, daunorubicin 50 mg/m 2 × 3], and consolidation [Ara-C 12 g/m 2 × 4 then 5+1 chemotherapy × 4 (Ara-C 100 mg/m 2 × 5, daunorubicin 50 mg/m 2 × 1)]. Radiotherapy (36Gy) was delivered to the NP. At three years, his marrow biopsy, computerized tomogram (CT) scan, and random NP biopsy were all normal. The case illustrated some interesting features of GS. Firstly, GS involvement of the ear, nose, and throat area occurs occasionally, although almost all reported cases were accompanied by marrow disease [1]. Involvement