449-PA10 Usefulness of PCR in the detection of M. tuberculosis (M.tb) DNA from formalin fixed paraffin embedded lymph-nodes (FFPEL) among patients HIV(+) or HIV(−)

Abstract Context—Within the last 15 years, evaluation of sentinel lymph nodes (SLNs) has become the most popular method of early staging of several malignancies, including melanoma. Sentinel lymph nodes are usually examined on formalin-fixed, paraffin-embedded sections and by routine histology/immunohistochemistry (research protocols have used other techniques such as polymerase chain reaction). Approximately 20% of patients with cutaneous melanoma have metastasis in the SLN. In most studies, detection of positive SLN conveys a poorer prognosis for patients with cutaneous melanoma. Objective—To review the morphologic patterns of melanoma metastasis in the SLN, the differential diagnosis, and the quantification of tumor burden as a prognostic factor. Data Sources—Personal observations and review of the pertinent literature. Conclusions—Evaluation of sentinel lymph nodes is certainly becoming a widespread technique and most authors agree on its prognostic power for staging patients with cutaneous melanoma. Current studies are evaluating the possible therapeutic value of removal of positive SLNs.

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Immuno- and Enzymehistochemical Characterization of ‘Plasmacytoid T-Cells’ in Formalin-Fixed Paraffin-Embedded Tissue of Reactive Lymph Nodes

Pathology - Research and Practice ◽

10.1016/s0344-0338(11)80581-9 ◽

1991 ◽

Vol 187 (7) ◽

pp. 848-855 ◽

Cited By ~ 1

Author(s):

M. Takeshita ◽

H. Müller ◽

D. Mix ◽

H.J. Stutte ◽

H.L. Schmidts

Keyword(s):

T Cells ◽

Lymph Nodes ◽

Formalin Fixed Paraffin ◽

Formalin Fixed Paraffin Embedded ◽

Formalin Fixed

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Histopathology of Experimental Plague in Cats

Veterinary Pathology ◽

10.1354/vp.38-2-165 ◽

2001 ◽

Vol 38 (2) ◽

pp. 165-172 ◽

Cited By ~ 19

Author(s):

R. P. Watson ◽

T. W. Blanchard ◽

M. G. Mense ◽

P. W. Gasper

Keyword(s):

Lymph Nodes ◽

Lymphoid Tissue ◽

Pneumonic Plague ◽

Naturally Occurring ◽

Large Numbers ◽

Formalin Fixed Paraffin ◽

Organ Systems ◽

Formalin Fixed Paraffin Embedded ◽

Adult Cats ◽

Formalin Fixed

Formalin-fixed paraffin-embedded archival tissues of seven adult cats of both sexes that died after being experimentally infected with Yersinia pestis were examined light microscopically to characterize the lesions. The cats were exposed in two groups using two routes of infection: ingestion of Y. pestis-infected rodent or a subcutaneous injection of Y. pestis to simulate a flea bite. Immunohistochemistry was performed on tissues from all organ systems from a representative cat from each group to determine the distribution of Y. pestis bacilli during infection. In all seven cats, bubonic plague lesions were seen. The lesions of pneumonic plague were present in two cats. Septicemic plague was confirmed in all seven cats by bacteriologic culture. Aggregations of bacteria were seen in lymphoid tissue in all cats and in lung tissues from the two cats with pneumonic plague. The most consistent histologic finding was necrosuppurative inflammation in the lymph nodes. Invariably, Y. pestis bacteria were present in large numbers at affected sites. Orally infected cats had more numerous lesions in the lymph nodes of the head and neck regions. These experimentally induced cases of feline plague document that cats are unique among carnivores in exhibiting bubonic, pneumonic, and septicemic plague following exposure to Y. pestis. The lesions of the orally infected cats were consistent with those previously described for naturally occurring Y. pestis infections in cats and corroborate the contention that cats most commonly contract plague by eating Y. pestis-infected rodents and not via flea bite. The histopathology of Y. pestis disease in these cats is comparable to that described for human plague.

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Optimal Probe Size and Fixation Time for the Detection of Porcine Circovirus–2 DNA by in Situ Hybridization in Formalin-Fixed, Paraffin-Embedded Tissue

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870902100509 ◽

2009 ◽

Vol 21 (5) ◽

pp. 649-654 ◽

Cited By ~ 7

Author(s):

Yooncheol Ha ◽

Chanhee Chae

Keyword(s):

In Situ Hybridization ◽

Lymph Nodes ◽

Porcine Circovirus ◽

Fixation Time ◽

Formalin Fixed Paraffin ◽

Probe Size ◽

Formalin Fixed Paraffin Embedded ◽

The Difference ◽

Formalin Fixed

Probe size and fixation time for detecting Porcine circovirus–2 (PCV–2) by in situ hybridization in formalin-fixed, paraffin-embedded lymph nodes from experimentally infected pigs were optimized. In situ hybridization using a 169–base pair (bp) probe detected significantly fewer PCV–2–positive cells than when using 8 other larger probes ( P < 0.05). The difference in hybridization intensity between smaller probes (169 and 225 bp) and larger probes (416, 473, 571, 631, 693, and 753 bp) was statistically significant ( P < 0.05). The PCV–2–positive cells were consistently detected in lymph nodes fixed up to 3 days; thereafter, the number of positive cells declined. The PCV–2–positive cells were detected in lymph nodes fixed for up to 730 days. The difference in hybridization intensity between samples fixed for a short term (1 or 3 days) and a longer term (4–730 days) was statistically significant ( P < 0.05). The data demonstrates that the optimal probe size and fixation time for detecting PCV–2 in formalin-fixed, paraffin-embedded lymph nodes is 473 bp and 1–3 days, respectively.

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