ABSTRACT
AIMS: Altering the length of time specimens are placed in fixative without compromising analytical testing accuracy is a continuous challenge in the anatomical pathology lab. The aim of this study was to determine under controlled conditions the effects of variable fixation time on breast biomarker expression in human breast cancer cell line-derived xenografted (CDX) tumours. METHODS: CDX tumours using strong oestrogen receptor (ER)-positive, Her2-negative (MCF7) and weak ER-positive, Her2 equivocal (T47D) breast cancer cell lines were fixed for various times ranging from 1 to 336â hours in 10% neutral buffered formalin. CDX tumours were processed according to routine biomarker testing protocols and stained for ER and Her2 immunohistochemistry (IHC) and processed for HER2 fluorescence in situ hybridisation (FISH). The tumours were evaluated using Allred scoring for ER and current ASCO/CAP guidelines for Her2, and by objective cell counting methodology. RESULTS: No differences were found in expression of ER in either MCF7 or T47D CDX tumours under variable fixation. T47D tumours displayed equivocal Her2 staining when fixed for 24â hours, but fixation for ≤8â hours resulted in consistently negative staining while tumours fixed for >72â hours demonstrated consistent equivocal staining (p<0.01). Cell counting assays revealed only a significant increase in sensitivity in tumours fixed for >72â hours (p<0.01). As expected, FISH results were unaffected by variable fixation. CONCLUSIONS: Neither shortened nor prolonged fixation affects ER expression, consistent with previous findings. In equivocal Her2-expressing tumours, however, increasing fixation increased the sensitivity of Her2 IHC reporting while not affecting FISH.
Subject(s)
Biomarkers, Tumor/analysis , Mammary Neoplasms, Experimental , Receptor, ErbB-2/analysis , Receptors, Estrogen/analysis , Tissue Fixation/methods , Animals , Female , Heterografts , Humans , Immunohistochemistry , In Situ Hybridization, Fluorescence , Mice , Time Factors , Tissue Array AnalysisABSTRACT
Interpretation of postmortem injuries, including their differentiation from those produced antemortem, may be difficult even for experienced forensic pathologists. A variety of animals or insects residing in the death environment may alter the appearance of the deceased. Dictyoptera blattaria (the cockroach) is common in the residential setting. Three cases of sudden and unexpected infant death are presented in which postmortem injuries inflicted by cockroaches initially raised concern of nonaccidental injury. The true nature of the lesions was not recognized by the people at the death scene and, in one case, observation of neck injuries raised suspicion of possible strangulation. In another, the lesions were thought to be burns of different ages. Cockroaches are omnivorous scavengers that devour keratin. They will bite human flesh in both the living and dead with resultant injury. Recognition of cockroach bites will help in the evaluation of injuries discovered during child death investigations.
Subject(s)
Child Abuse/diagnosis , Cockroaches/physiology , Forensic Medicine/methods , Insect Bites and Stings/pathology , Postmortem Changes , Sudden Infant Death/etiology , Animals , Female , Humans , Infant , Male , Skin/pathology , Sudden Infant Death/pathologyABSTRACT
The authors studied the respiratory diaphragm in 50 normally grown infants and children aged 1 to 16 years at the time of sudden death. By comparing the weights of both costal diaphragm and heart with age and height, the authors found that the diaphragm grows proportionately to the body as a whole and to the heart in particular. Diaphragmatic contraction band necrosis was found in 15 cases (30%). The incidence was similar in subjects dying of asphyxia (five of 21) to that in those dying of trauma (five of 20). It was present in two of 15 of those that died at once, and 13 of 35 of those who survived for varying periods with or without cardiopulmonary resuscitation. Myocardial contraction band necrosis was more common than diaphragmatic contraction band necrosis, being present in five of 11 of those who died at once, and 16 of 26 of those that survived for a period. Among individual subjects, the authors found no correlation of the presence of the diaphragmatic lesion with either cause or mode of death. Based on a comparison with the morphologically similar myocardial lesion, the etiopathogenesis of diaphragmatic contraction band necrosis may concern a local catecholamine effect.
