Telepathologic review: utility, diagnostic accuracy, and interobserver variability on a difficult case consultation service.

The diagnostic accuracy of telepathologic analysis has not been compared to that of conventional light microscopic review on a difficult case consultation service. The anatomic pathology consultation files of the University of Iowa were retrospectively examined, and 105 difficult cases from a variety of organs were chosen for real-time telepathologic and light microscopic review. The telepathologic and light microscopic crude agreement of five pathologists were compared, with use of the original consultation diagnosis as the "gold standard." Cases were scored as correct, partially correct, or incorrect. After making a video diagnosis, the pathologists reported whether they wanted to review the case with use of a light microscope. The pathologists performed significantly better with the light microscope, even after excluding cases in areas of inexpertise (P = .005). The mean percentage of cases that the pathologists wanted to review with the light microscope was 64%, and the major reason for review was diagnostic uncertainty. Cases incorrectly diagnosed with use of the video monitor were almost always requested for review. We conclude that, on a difficult case consultation service, pathologists perform significantly better with use of light microscopic than with telepathologic analysis; rarely make an incorrect diagnosis and do not request that case for light microscopic review; and exhibit high telepathologic diagnostic accuracy in areas of expertise.

Atypical glandular cells of undetermined significance. Diagnostic accuracy and interobserver variability using select cytologic criteria.

Histologic follow-up of patients with the Bethesda system cervical-vaginal diagnosis of atypical glandular cells of undetermined significance (AGUS), "favor endocervical origin", or "not otherwise specified" (NOS) shows a high percentage of clinically significant (neoplastic or preneoplastic) lesions. Using the criteria of atypical single cells, irregular nuclear membranes, and decreased cytoplasm, eight observers retrospectively reclassified 88 AGUS, "favor endocervical", or NOS smears using a probabilistic scheme. Follow-up showed 46 clinically significant and 42 benign lesions. The mean accuracy for all observers and the experienced observers was 65% and 72%, respectively. For the experienced observers, the mean specificity of a "favor clinically significant" category was 72%; the mean sensitivity of a "favor benign" category was 90%. For the less experienced observers, subclassification had poor predictive value. We conclude that experienced observers may use specific criteria to correctly subclassify AGUS lesions, and this may aid in patient management.

Lymphoproliferative disorder of granular lymphocytes. A heterogeneous disease.

Lymphoproliferative disorders of granular lymphocytes (LDGLs) represent a family of diseases that are morphologically similar but diverse with regard to immunophenotype, function, and clonality. In this article, we report three informative cases and propose a modification of the current classification of LDGLs. Our first case is an example of natural killer cell LDGLs (CD2+, CD3-, CD16+, CD57+/-). Based on a review of the literature, we suggest that natural killer cell LDGLs can be divided into two subgroups (types 1 and 2) according to the expression of CD57. Reduced expression of CD57 may distinguish between patients with a poorer prognosis. The remaining two cases illustrate examples of T-cell LDGLs (CD2+, CD3+, CD8+, CD57+) that differ mainly in their expression of CD16. The CD16+ T-cell LDGLs (type 1) usually show a clonal rearrangement of the T-cell receptor-beta chain gene, whereas CD16- T-cell LDGLs (type 2) may show a germline configuration, suggesting a reactive rather than a neoplastic process. Pathologists should differentiate LDGLs from other chronic lymphoproliferative diseases, since most cases evolve slowly and aggressive cytoreductive therapy is usually unwarranted.