[IDENTIFICATION OF COMINGLED TISSUE WITHIN A FORMALIN-FIXED PARAFFIN-EMBEDDED SAMPLE USING FORENSIC GENETICS - A TOOL FOR PREVENTION OF MISDIAGNOSIS].

INTRODUCTION: Processing of formalin-fixed, paraffin-embedded (FFPE) tissues is routine practice in the preparation of biopsy specimens for pathological evaluation. Avoiding misdiagnosis due to a mix-up of tissues from different patients requires the utilization of molecular techniques since routine histopathology cannot detect such occurrences, especially if the comingled tissues are of the same type. The Biology Laboratory of the National Center of Forensic Medicine utilizes dedicated forensic procedures to ensure reliable DNA profiles based on short tandem repeats (STR's) from various sample types. These protocols are designed to evaluate even highly degraded samples such as those expected from FFPE tissues. The highly discriminative power profiles are then matched to a reference DNA sample taken from the patient to allow for inclusion or exclusion of the tissue source in question. The following case represents the effective usage of forensic genetics for detection of tissues' cross contamination in FFPE. A 52-year-old female patient was diagnosed with High Grade Dysplasia (HGD) from a sample excised during colonoscopy. DNA extractions taken from FFPE tissues matched the patient. A few additional alleles found in one of the profiles suggested the presence of a residual minor contributor. Out of six embedded tissue fragments, one was found to be a HGD and was marked as such on the slide. The HGD speck was then scraped from the microscopic slide and processed for DNA extraction. The results showed a single DNA profile of a male. Molecular analysis detected a cross contamination of colon tissues. In this case, collaboration between the medical examiner and the forensic laboratory permitted this important discovery that prevented misdiagnosis and possible severe consequences of inappropriate treatment.

[Detection of wooden rod in pleural and peritoneal cavities during forensic autopsy].

INTRODUCTION: A rare event of fatal sexual assault by the insertion of a wooden rod through the anus to the upper chest is reported. Examination of the body at the scene did not raise any suspicion of assault while the subsequent autopsy revealed findings that changed the assessment of the cause of death and the circumstances. CASE HISTORY: The body of a 57 years old man with a history of psychiatric illness was found in his room. At autopsy a round wooden rod which was inserted through the anus was found in the peritoneal and pleural cavities. In addition, signs of manual pressure were detected on the neck and trunk, and on the head and extremities signs of blunt trauma were observed. DISCUSSION: In patients affected by mental disorders it is difficult to distinguish between self-inflicted anal injuries and injuries sustained during an attack. Detection of damage to other areas of the body (such as the neck) assist in determining the nature of the assault. SUMMARY: This case demonstrates the need for a full autopsy in every case of death under unclear circumstances, especially when a limited examination of the body can't determine the type of death (natural, accident, suicide or homicide).

[The prevalence of physical evidence in the anogenital area in sexual assault cases of children in Israel].

INTRODUCTION: Sexual abuse includes obscenity, rape and sodomy. Forensic medical examinations routinely include the genital area, anus and the body of the victims for signs of recent or old injury. OBJECTIVES: To evaluate the incidence of physical evidence in forensic sexual abuse cases and to compare the Israeli findings to data from other countries, including the USA. METHODS: The study was conducted during one calendar year in Israel and included 95 children from infancy to 16 years of age, of whom 83% were females. Examination results were defined by the presence of physical injury or its absence. These findings were classified by their location in the anogenital area or other body areas and findings in the anogenital area were further classified by their likelihood to have been caused by a sexual assault. The results of the examination were related to parameters such as age and sex of the participants, length of time since the last assault, and the degree of proximity between the suspected assailant and the victim. RESULTS: Evidence of physical abuse was found in 41 patients, in 37 (39%) of these cases physical abuse was detected in the anogenital area. In all these cases of anogenital abuse, 11 (12%) showed clear evidence of sexual assault and five of them had recent signs of injury; 80% of the recent injuries in the anogenital area were identified in patients within the first 24 hours after the assault. CONCLUSIONS: The prevalence of clear evidence of sexual assault in the U.S. ranges from 3-23%, in Italy 9.5%, in Thailand 32% and in Denmark 40%. In Israel, as elsewhere in the world, few cases of sexual assault in children will have clear evidence of a sexual nature. A lack of physical evidence does not rule out sexual assault, therefore, finding physical evidence during an examination is the exception rather than rule. Questioning the victim and investigating the circumstances of the case are crucial elements in all instances of presumed sexual assault on children.