The human hematopoietic progenitor cell antigen (CD34) in vascular neoplasia.

The human hematopoietic progenitor cell antigen CD34 is synthesized and expressed by early normal hematopoietic progenitor cells and by many acute leukemias. Anti-CD34 antibodies also have been reported to stain blood vessels in tissue sections, and, more recently, CD34 mRNA has been detected in vascular endothelial cells. Therefore, the authors studied the diagnostic utility of immunohistochemical CD34 antigen detection in tumors of endothelial cell derivation and compared the results with stains for von Willebrand (vW) factor. A wide variety of epithelial and mesenchymal neoplasms also were examined to assess the specificity of CD34 for vascular neoplasia. Seven cases of angiosarcoma (seven of seven), five cases of Kaposi's sarcoma (five of five), and eight cases of epithelioid hemangioendothelioma (eight of eight) were moderately to strongly positive for CD34. This reactivity was equally intense in frozen sections, alcohol-fixed tissue, and formalin-fixed specimens. In many cases, the malignant endothelial cells stained more strongly than adjacent benign endothelium. Moreover, in most cases CD34 positivity was quantitatively and qualitatively stronger than staining for vW factor. Two cases of hemangiopericytoma (two of two) were CD34 positive but stained less intensely than the angiosarcomas, Kaposi's sarcomas, or hemangioendotheliomas. Five of six cases of hemangioma also stained positively for CD34; the nonreactive tumor in this group was the only one among 28 vascular neoplasms studied that was not reactive for CD34. In comparison, 9 of the 28 vascular tumors did not stain for vW factor. Three hundred fifty-seven tumors of nonvascular derivation also were examined for CD34 antigen expression. Focal light staining was seen in one pulmonary squamous cell carcinoma; moderate to intense staining was observed in half of the epithelioid sarcomas studied (8 of 16) and in a minority of leiomyosarcomas (3 of 22). These findings indicate that CD34 is a sensitive and relatively specific marker for neoplasms of vascular origin.     

Monocytoid B-cell lymphoma: its evolution and relationship to other low- grade B-cell neoplasms

Monocytoid B-cell lymphoma (MBCL) is a newly recognized B-cell neoplasm of uncertain histogenesis. The cytologic features of the neoplastic monocytoid B lymphocytes are virtually identical to those of hairy cell leukemia (HCL). As with HCL, progression of MBCL to a higher histologic grade is very unusual. However, whereas circulating leukemic cells are a characteristic feature of HCL, peripheral blood involvement has not been reported in MBCL. We recently studied a patient with MBCL of the spleen and axillary lymph nodes who developed peripheral blood involvement by MBCL cells. Unlike the cells of HCL, the circulating MBCL cells exhibited strong acid phosphatase activity that was tartrate sensitive. The leukemic cells had the antigenic phenotype IgM lambda, CD20+, CD11c+, CD5-, CD25(TAC)-, and PCA-1-. Immunogenetic studies of both lymph node and peripheral blood cells revealed identical immunoglobulin heavy-chain gene rearrangements. When compared with a series of HCL, the immunophenotype was similar except for the absence of PCA-1 and TAC. Progression of the MBCL to a large cell lymphoma, also expressing IgM lambda, was documented in an abdominal lymph node of this patient. Therefore, although rare, peripheral blood involvement by lymphoma cells may occur during the course of MBCL and should be distinguished from HCL with cytochemical and immunophenotypic studies. In addition, comparison of the clinical, pathologic, and immunologic features of MBCL with those of other low-grade B-cell neoplasms suggests that a close lineage relationship exists between MBCL and HCL.     

Thermal injury resulting from application of a granular mineral hemostatic agent

BACKGROUND: Uncontrolled hemorrhage accounts for the majority of deaths in combat. Effective topical hemostatic agents suitable for use on the battlefield may be valuable in controlling hemorrhage until definitive surgical intervention is possible. In an effort to identify a hemostatic agent suitable for battlefield use, we evaluated several potential hemostatic agents in a swine injury model and noted thermal injury to tissues with a granular mineral hemostatic agent (QuikClot). METHODS: Anesthetized swine were maintained with a mean arterial pressure in excess of 60 mm Hg. Cutaneous, muscular, hepatic, splenic, venous, and arterial wounds were created in a standardized fashion. Topical hemostatic agents were immediately applied to the wounds and the amount of bleeding and time to hemostasis were noted. RESULTS: The results reported here are part of a larger study in which a variety of hemostatic agents were evaluated. Only the findings related to the granular mineral hemostatic agent are discussed here. Application of the agent resulted in elevated tissue surface temperatures in excess of 95 degrees C and internal tissue temperatures exceeding 50 degrees C, 3 mm deep to the bleeding surface. Necrosis of fat and muscle were noted as well as full and partial thickness cutaneous burns. CONCLUSIONS: Topical administration of a granular mineral hemostatic agent to a variety of wounds in an experimental swine model resulted in thermal tissue injury and necrosis. Suggestions for reducing the extent of injury with this product are offered.     

Prostatic acid phosphatase in carcinoid tumors. Immunohistochemical and immunoblot studies.

The immunohistochemical demonstration of prostatic acid phosphatase (PAcP) and/or prostate-specific antigen (PSA) has been accepted as being reliable in identifying metastatic adenocarcinoma of prostate origin. However, islet cell tumors, especially hindgut-derived carcinoid tumors, have occasionally been reported to be positive for PAcP. We therefore studied a series of carcinoid tumors of the lung and gastrointestinal tract immunohistochemically for PAcP expression by using two polyclonal antibodies and one monoclonal antibody. Thirty-three carcinoid tumors were examined. All five rectal carcinoids in the series showed convincing PAcP positivity with at least two of the three anti-PAcP antibodies. No significant PAcP positivity was observed in the remaining 28 foregut- and midgut-derived carcinoid tumors, except for weak focal positivity in one lung carcinoid. PSA antibody reacted negatively in all cases. Western blots of an aqueous cell lysate from one rectal carcinoid revealed protein bands in the region of 45-55 kd that immunoreacted with anti-PAcP antibodies, confirming the validity of the immunostains. These results suggest that PAcP positivity is common in rectal carcinoid tumors and that it most likely represents true PAcP expression. This seemingly aberrant protein expression may be explained by the shared cloacal derivation of the rectum and prostate, giving rise to cells with both endocrine and partial prostatic epithelial differentiation.     

Pharyngoesophageal diverticula simulating thyroid nodules: An unusual occurrence with unique features

Pharyngoesophageal diverticula (PED) of the Zenker's and Killian‐Jamieson types arise in close proximity to the thyroid gland, and may rarely be confused with a thyroid nodule on ultrasonography. In this brief report, we detail the cytologic, clinical, and radiologic findings of three PED that were thought to be thyroid nodules, and were subjected to fine‐needle aspiration (FNA). The patients were females with an age range of 51‐64 years. All three patients had multiple thyroid nodules, and two patients reported symptoms attributable to the diverticulum. Nodule sizes ranged from 1.0 to 2.7 cm, and either the right or left thyroid lobe could be involved. Microcalcifications were present by ultrasonography in all three cases. FNA of these thyroid nodule mimics showed squamous cells with granular or amorphous debris, bacterial and/or fungal colonies, inflammation, and food particles. These cytologic features, particularly the presence of vegetable or meat fragments, are characteristic, and have also been reported in the few previous reports of PED. The presence of a diverticulum was confirmed with imaging studies in all our patients. Although a rare occurrence, the inadvertent FNA of a PED masquerading as a thyroid nodule is important to recognize, as a recommendation for appropriate radiologic studies could potentially avoid inappropriate therapy for thyroid disease.     

Localization of amplified MYC gene sequences to double minute chromosomes in acute myelogenous leukemia

Cytogenetic and molecular studies were performed on two dmin-bearing acute myelogenous leukemia (FAB-M2) samples. Both cases were characterized by complex karyotypes containing interstitial deletions of the long arm of chromosome 8 altering band 8q24.1, aberrations affecting the short arm of chromosome 17, and multiple double minute chromosomes (dmin). Using a 1.4 kb cDNA probe coding for the third exon of the MYC oncogene, DNA slot blots indicated MYC gene sequences were amplified in both samples. Fluorescence in situ hybridization using a 9.0 kb genomic probe for MYC was performed in one we and localized the amplified MYC gene sequences to the dmin. Neither patient achieved a complete remission using traditional induction chemotherapy. The complex karyology with amplification of MYC gene sequences appears to represent a poor prognostic subgroup of acute myelogenous leukemia. Genes Chrom Cancer 9:62-67 (1994). © 1994 Wiley-Liss, Inc.     

The Aviation Psychology Program at RAF Upper Heyford

An Aviation Psychology Program was started in September, 1985 at RAF Upper Heyford, with the focus on teaching flight commanders and their wives to recognize and deal with aircrew member and family stress. The overall goal is to prevent aircraft accidents and mishaps caused by human factor errors. Case reports are presented which demonstrate the value of the aviation psychologist becoming integrated in the flying community. The program has been successful, but needs further commitment and support.     

Myelodysplasia and acute myeloid leukemia occurring after autologous bone marrow transplantation for lymphoma

Secondary hematopoietic disease manifesting as acute myeloid leukemia, myelodysplastic syndrome or clonal karyotypic abnormalities, has been recently recognized as a relatively frequent and potentially serious complication of autologous bone marrow transplantation for both Hodgkin's disease and non-Hodgkin's lymphoma. The available evidence suggests the disease results primarily from repeated exposure of the host stem cells to therapeutic agents before the time of transplant, but a conspiratory role for the transplantation procedure itself cannot be entirely excluded. Strategies to decrease the incidence of secondary hematopoietic disease include earlier stem cell harvest and/or transplantation, and the performance of screening karyotypic studies on the bone marrow prior to autologous grafting.