Diagnostic accuracy of a rural live video telepathology system.

Accuracy of diagnoses rendered using a live video telepathology network was assessed for permanent sections of surgical pathology specimens. To determine accuracy, telepathology diagnoses were compared with those obtained by directly viewing the glass slide using a standard microscope. A total of 294 cases were read via both telepathology and glass slide by attending pathologists at a tertiary care medical center. Overall accuracy was defined as exact concordance between diagnoses. Clinically insignificant differences in diagnoses were excluded to determine clinically significant accuracy. For the 285 cases with complete data, the overall accuracy for telepathology was 0.912 (95% confidence interval [CI], 0.872-0.941), whereas the overall accuracy for glass slide readings was 0.968 (95% CI, 0.939-0.985). This difference is statistically significant (p = 0.009). When focusing on clinically significant discrepancies, where the difference in diagnosis might affect therapeutic decisions, the video accuracy was only slightly less than the glass slide accuracy (0.965 [95% CI, 0.934-0.982] vs. 0.982 [95% CI, 0.957-0.994], respectively), but this difference is not statistically significant (p = 0.302). Most of the cases with clinically significant differences involved lesions with inherently high interobserver variation. Certainty of diagnosis did not differ between video and glass slide readings (p = 0.911), but there was an association between certainty of diagnosis and diagnostic accuracy for video (p = 0.003 for clinically significant accuracies). Based on these findings, we recommend when using this telepathology system that only preliminary diagnoses should be given in the following situations: for diagnostic areas with known high interobserver variability; when the consultant has any degree of uncertainty about the presence or absence of the lesion in question; and when there is insufficient experience using telepathology as a diagnostic medium.

Prospective comparison of direct immunofluorescence and conventional staining methods for detection of Giardia and Cryptosporidium spp. in human fecal specimens.

In a prospective comparative study, 2,696 consecutive fresh stool specimens over the course of 1 year were examined for Giardia lamblia and Cryptosporidium parvum by using a direct immunofluorescent-monoclonal antibody stain (for unspun specimens) and conventional staining methods (chlorazol black E for Giardia cysts and modified Kinyoun acid-fast for Cryptosporidium oocysts). The direct immunofluorescent-monoclonal antibody method resulted in a significantly increased detection rate for both giardia (118 versus 79 specimens, 49.4%; P = 0.006) and cryptosporidia (39 versus 23 specimens, 69.6%; P = 0.055).

Comparison of fecal lactoferrin latex agglutination assay and methylene blue microscopy for detection of fecal leukocytes in Clostridium difficile-associated disease.

The fecal lactoferrin assay was more sensitive (75%) than methylene blue microscopy (40%) for the detection of leukocytes in Clostridium difficile toxin-positive fecal samples. Although limited sensitivity and specificity precludes its use as a laboratory screening test, it may be a more useful initial test in an algorithm for clinically suspected C. difficile-associated disease.

Comparison of four methods in the diagnosis of Clostridium difficile disease.

Nine hundred forty-five stool specimens from patients suspected of having Clostridium difficile disease were examined using a cell culture cytotoxicity assay (CTA), two enzyme immunoassay (EIA) kits (Cytoclone for toxins A and B; VIDAS for toxin A) and a latex agglutination assay (CDT). One hundred nineteen specimens had positive titers (> or = 90) in the CTA; clinical review of 16 discordant samples and 49 controls supported the significance of 90 as the positive cut-off titer. The performance of the two EIAs and the latex assay was assessed relative to CTA titers of the samples. Sensitivity was < or = 50% for all three assays for the 24 specimens with CTA titers of 90, but it reached 97-100% for the two EIAs and 84% for the latex assay at titers of > or = 2,250. The Cytoclone EIA exhibited higher sensitivity at the lower positive titers. Overall, specificity of the methods ranged from 96.7% (CDT latex assay) to 99.1% (Cytoclone EIA).

Use of the Quantitative Buffy Coat system for detection of parasitemia in patients with babesiosis.

Quantitative Buffy Coat analysis and blood smears were performed on a total of 47 blood samples. The technique showed 100% correlation with the blood smears in 9 samples containing babesia and 10 samples containing malaria, with some differential features distinguishing the two infections. Quantitative Buffy Coat analysis provides a simple and rapid method for the detection of parasitemia in cases of babesiosis.

Breast lymphoma. A B-cell spectrum including the low grade B-cell lymphoma of mucosa associated lymphoid tissue.

We studied the morphologic, immunologic, and clinical features of 31 cases of malignant lymphoma involving the breast. Primary breast lymphoma occurred in nine women with a median age of 69 years (range, 51-87 years); median follow-up was 31 months (range, 9-67 months). Eight cases were low grade, one was high grade, and all expressed B-lineage antigens. Four cases had features of lymphoma of mucosa-associated lymphoid tissue (MALT); three were free of disease after excision alone at 10, 12, and 48 months, whereas the fourth relapsed with transition to immunoblastic lymphoma and died at 25 months. Four patients had follicular lymphomas, three of which relapsed, causing death from active disease at a median of 55 months (range, 25-67 months). One case of small noncleaved cell lymphoma relapsed, causing death at 31 months. Lymphoma secondarily involved the breast in 22 patients (21 women, one man) with a median age of 60 years (range, 39-83 years) at breast relapse; these patients were followed for a median of 88 months (range, 2-271 months) from primary diagnosis and 4 months (range, 0-116 months) from breast relapse. Nineteen patients had prior documented lymphomas (10 nodal or splenic, nine extranodal), and breast involvement most commonly occurred as part of widespread, predominantly nodal disease. Three patients had breast involvement by lymphomas that were generalized at diagnosis or staging. Thirteen cases were low grade (nine follicular), seven intermediate grade, and one high grade; 19 of 20 cases expressed B-lineage antigens, and one expressed T-lineage antigens. Four cases had features of MALT-type lymphoma; in these patients, isolated breast relapses were interspersed with other extranodal relapses, with interim resolution of disease after local or systemic therapy; two were free of disease and two were alive with localized disease on treatment at median follow-up of 60 months (range, 9-91 months). In contrast, 15 of 18 nonMALT lymphomas had widespread disease at breast relapse (median, 29 months; range, 0-259 months); 16 of 18 received systemic therapy, 10 died with active disease, and five of eight had disseminated active disease at last follow-up. Primary breast lymphomas were commonly low grade. The follicular lymphomas had clinical behavior similar to nodal follicular lymphoma. Primary MALT-type lymphomas were a distinct subset with a potential for disease-free survival after local therapy. Secondary breast lymphomas were heterogeneous and more commonly higher grade, although follicular lymphoma was the most common subtype.(ABSTRACT TRUNCATED AT 400 WORDS)

Use of the UV ParaLens adapter as an alternative to conventional fluorescence microscopy for detection of Pneumocystis carinii in direct immunofluorescent monoclonal antibody-stained pulmonary specimens.

The UV ParaLens light microscope adapter offers a useful and cost-effective alternative to conventional fluorescence microscopy for Pneumocystis carinii identification, particularly in AIDS patients. In a blinded study, in which 153 pulmonary specimens were examined for P. carinii by direct immunofluorescence, 40 of 42 specimens positive by fluorescence microscopy were also positive by ParaLens. No false positives were observed.

Perianal mass and recurrent cellulitis due to Enterobius vermicularis.

A unique case of enterobiasis presenting as recurrent cellulitis and a perianal mass in a six-year-old girl is reported. Complicated perianal lesions due to Enterobius are unusual. Only 10 previous cases are known, with unclear pathogenesis in most of them, although mucosal breaches and perianal crypt or gland entry have been postulated. The association of the mass in this case with a deep crypt, and the histopathologic finding of squamous epithelium focally surrounding the granulomatous reaction to the Enterobius eggs suggest that the worm entered the perianal tissues via a crypt. Local secondary bacterial infection can cause significant morbidity. Surgical excision of such granulomatous mass lesions is necessary in symptomatic or complicated cases.