Ptosis following radial keratotomy. Performed using a rigid eyelid speculum

Seven patients with acquired ptosis and normal levator function following anterior radial keratotomy are presented. Five of these patients then elected to undergo radial keratotomy of the opposite eye, and four had symmetrical lid fissures (mild bilateral ptosis) after bilateral surgery. Ptosis is a well-known complication of cataract extraction, but has not been reported following radial keratotomy. Unlike cataract extraction, radial keratotomy does not require anesthetic injections, bridle sutures, or conjunctival flaps. The rigid Knapp eyelid speculum used in these cases remains as the only apparent cause of eyelid trauma and subsequent ptosis. During radial keratotomy, the speculum was opened widely in order to provide good corneal exposure and avoid contact with the diamond knife. Contraction of the orbicularis oculi muscle against the rigid speculum may have traumatized the lid, resulting in a levator aponeurosis disinsertion and subsequent ptosis.     

Application of immunohistochemistry in the differential diagnosis of skin tumors

As with neoplasms in any tissue, skin tumors may be categorized as epithelial or mesenchymal, benign or malignant, and primary or metastatic. Immunoperoxidase stains are useful in elucidating the nature of the tumor cells, especially in poorly differentiated tumors. It is important to consider that tumors may exhibit staining patterns different from the typical or reported results. This may be because of intrinsic features of the neoplasm such as the aberrant expression of antigens (markers). Furthermore, the staining of the tumor may be affected by tissue preservation and fixation as well as by the selection of antibodies used for staining. For this reason, the pathologist should be vigilant in comparing the results of unknown tumors with standard controls, with results in the literature, and with his or her own experience. Unusual neoplasms may require additional tissue for analysis, study by other ancillary methods such as electron microscopy, or consultation by more experienced laboratories. These guidelines should be helpful in providing accurate diagnosis of skin tumors.     

An anti-EnaTS detected in the serum of an MiI homozygote

The serum of EH reacted with all red cells (RBCs) except her own, ficin- or trypsin-treated red cells, and En(a-) red cells. This reactivity defined an anti-EnaTS specificity. The red cells of the proposita typed as M-N+S-S+, Vw+Mur-Hil-Hut-Anek-Lane-, Wr(a-b+), EnaKT+. Red cells of five relatives were Vw+ and positive with her serum. Titration studies suggest that EH is genetically an MiI homozygote and that her Vw+ relatives are MiI heterozygotes. There is no history of consanguinity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting studies have agreed with the serologic observations. A variant sialoglycoprotein of faster mobility than normal glycoprotein A, but no normal glycoprotein A, was detected on her red cells. Treatment with N-glycanase did not alter the mobility, which indicated that there was no N-glycosylation of residue 26. These findings are in agreement with the reported properties of the Mi.I-specific glycoprotein A. The relatives' Vw+ red cells showed the variant sialoglycoprotein and normal glycoprotein A. EH appears to be the first reported MiI homozygote.     

The necessary and the unnecessary transfusion: a critical review of reported appropriateness rates and criteria for red cell transfusions

BACKGROUND: The purpose of this study was to evaluate the criteria for assessing the appropriateness of red cell transfusions. The data were obtained by a computer search of all English-language literature from 1966 to October 1992. STUDY DESIGN AND METHODS: Nine studies were selected, which dated from 1986 to 1989 and employed explicit criteria evaluating the appropriateness of red cell transfusion in adults. The following data were abstracted from all studies: study design, timing, location, criteria for evaluating appropriateness, and rate of appropriate or inappropriate transfusions. RESULTS: Five studies evaluated transfusion appropriateness. Appropriateness rates ranged from 88 to 99 percent in three studies, and inappropriateness rates ranged from 0.3 to 57.3 percent in two studies. Four studies evaluated transfusion inappropriateness and reported inappropriateness rates of 18 to 55 percent. Substantial variation was found in the criteria for an appropriate or an inappropriate transfusion. Appropriateness rates did not depend upon characteristics of the study design, location, or timing of data collection. Restrictiveness in the criteria used to determine appropriateness and the use of additional implicit evaluation after an initial explicit review affected appropriateness rates. CONCLUSION: In the 1980s, high rates of inappropriate transfusion and low rates of appropriate transfusion were still reported. Appropriateness rates varied widely, in part because of marked variation in the criteria for an appropriate transfusion. Newly derived standards for an appropriate red cell transfusion, published in 1992, appear to provide a simple and objective means of evaluating the appropriateness of a transfusion. Appropriateness rates resulting from the application of these new standards have not yet been determined.     

Electronmicroscopic examination of white cell reduction by four white cell-reduction filters

The mechanisms of white cell (WBC) reduction in 16-hour-old CPDA-1 red cell (RBC) concentrates by filtration on a column filter and on three different flatbed filters were studied by electron microscopy, with special emphasis on cell-to-cell interaction, cell damage, and interaction of blood cells with the material. Generally, lymphocytes were removed by mechanical sieving and monocytes by adherence and mechanical sieving. Granulocyte depletion occurred by mechanical sieving, direct adhesion to the fibers, and indirect adhesion to activated and spread platelets. In the column filter, most granulocytes were captured by adhesion. In the coarse layers of two of the flatbed filters, indirect adhesion was most prominent, whereas direct adhesion was most prominent in the other flatbed filter. For the most part, granulocytes were captured by direct adhesion in the fine layers, but in one flatbed filter, capture apparently occurred by mechanical sieving. The results of this study suggest that the efficiency and the mechanism of WBC reduction depend on the physicochemical characteristics of the non-woven materials in the filters as well as the cellular composition of the RBC concentrates.     

Tissue histiocyte reactivity with CD31 is comparable to CD68 and CD163 in common skin lesions

CD31 is a standard immunostain for evaluating vascular lesions of the skin, but CD31 reactivity for histiocytes is reported in only a small variety of pathological conditions. CD68 and CD163 are well recognized stains for cutaneous histiocytic lesions. We compared immunostaining of CD31 within that of CD68 and CD163 in five cases each of cutaneous lesions containing histiocytes: healing biopsy site, granuloma annulare, xanthogranuloma, ruptured follicular cyst and sarcoidosis. Reactivity was graded on a scale of 0–3 for brightness of immunostaining. Immunoreactivity was seen in histiocytes in all specimens for CD31, CD68 and CD163. The average intensity of staining was 1.7–2.5 for CD31, 2.6–3 for CD68 and 2.9–3 for CD163. The staining was somewhat less for CD31 because the reactivity is localized on the cell surfaces, whereas CD68 and CD163 react with cell surfaces and cytoplasm. We conclude that histiocytes in cutaneous lesions stain for CD31 and the staining is comparable to, but less intense, than that seen with CD68 and CD163. Caution is suggested in interpretation of CD31 staining in skin specimens, as CD31 shows reactivity with histiocytes as well as endothelial cells.     

Lipomatous metaplasia of superficial dermis

Lipomatous metaplasia is an uncommon phenomenon. After identifying the presence of a band of adipocytes in the superficial reticular dermis underlying two excisions for basal cell carcinoma, we prospectively reviewed all skin specimens accessioned in our laboratory over a 6‐month period and identified eight additional cases. In each example there was a band of adipocytes in the upper dermis, at the level of solar elastosis that was widely separated from the subcutaneous fat by a normal appearing reticular dermis. The cells were positive for S100 and negative for CD163. No connection between the superficial band of adipocytes and the subcutaneous or periappendageal fat was seen. The alterations were flat in configuration without polypoid changes. Eyerich et al. reported lipomatous metaplasia in the dermis of a patient with acute generalized exanthematic pustulosis and psoriasis, and postulated this to be a postinflammatory phenomenon. Fatty metaplasia occurs within a variety of cutaneous neoplasms including nevi, adnexal tumors and peripheral nerve sheath tumors. However, superficial dermal fatty metaplasia beneath cutaneous neoplasms is a newly described phenomenon and we suspect this process represents fatty metaplasia within solar elastosis and that it may occur more frequently than recognized.