HELP DESK ... Commonwealth University Health System, Richmond, Virginia. ... ting the harvest of fluids and/or fresh tissue for autolysis-free histology and.
Cytopathology
HELP DESK Experts address relevant and topical questions in the field | Edited by Gladwyn Leiman, MBBCh, FIAC, FRCPath
Cora G. Uram-Tuculescu, MD Cora Uram-Tuculescu, MD, is an assistant professor in the Division of Anatomic Pathology at Virginia Commonwealth University Health System, Richmond, Virginia. She is board certified in Anatomic and Clinical Pathology as well as Cytopathology. She serves as Assistant Director of the Surgical Pathology fellowship program and Director of Anatomic Pathology Education. Her clinical interests are in breast, heart, lung, gynecologic, and genitourinary pathology and cytopathology.
Christine E. Fuller, MD Christine Fuller, MD, is Professor and Director of Neuropathology and Autopsy Pathology at Virginia Commonwealth University Health System, Richmond, Virginia, with a joint appointment in the Department of Neurosurgery. She serves as Vice Chairman of Pathology Graduate Medical Education as well as the Director of the Pathology Residency Program and Neuropathology Fellowship. She maintains an active diagnostic practice, which includes surgical brain, neuromuscular, and ophthalmic pathology samples as well as autopsy/forensic brain examinations. She serves a consultative role to the Office of the Chief Medical Examiner of Virginia and has acted as an expert witness on several high-profile legal cases.
Postmortem Cytology: Alive and Well in the Practice of Autopsy and Forensic Pathology Conventional (full) autopsy represents more than just dissection of organs and microscopic evaluation of tissues. It provides the centerpiece of forensic investigation and is an unrivaled clinical audit and educational tool for practicing physicians and trainees.1 Unfortunately, this procedure, whether it is hospital-based or in the forensic setting, is not without drawbacks and limitations, including negative psychological impact of the procedure on the deceased’s relatives, increased cost, and prolonged time to the final report.2 From a forensic standpoint, a provisional autopsy report based on conventional autopsy alone may not always provide key information sought by police investigators. To that end, cytology offers a viable alternative and adjunct to diagnosis in the workup of postmortem cases.
Alternatives to Conventional Autopsy The limited autopsy focuses on a specific problem, organ, or body cavity. It is used for cases in which religious or other reasons preclude full autopsy and when an infectious etiology represents a hazard to prosectors. Needle-core/ fine-needle aspiration biopsy may be employed in the autopsy setting, permitting the harvest of fluids and/or fresh tissue for autolysis-free histology and additional ancillary studies (microbiology, molecular, immunohistochemical, or genetic testing). Alternately, postmortem endoscopic techniques can provide visual inspection of organs and cavities and allow for sampling of any fluid or tissue of concern.3 Endoscopic examination of great vessels may be
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helpful when arterial pathology is suspected.4 Disadvantages of postmortem endoscopy include equipment cost, a lengthy time interval for acquiring and interpreting images, and limited access to scanners and specialized personnel. Postmortem imaging studies can provide supplementary information in cases with or without full autopsy by detecting internal injuries that would not otherwise be identified by routine dissection or external examination alone. In addition to standard roentgenography, computer tomography (CT) and/or magnetic resonance imaging (MRI) are frequently used in forensic and hospital-based autopsies. Postmortem CT is particularly useful for detecting fractures, internal hemorrhages, and other injuries, whereas MRI can be used for the evaluation of complex malformations or to facilitate localization of limited abnormal areas that require histologic evaluation for a definitive diagnosis. Although some have suggested that imaging techniques may serve as viable alternatives to full autopsy,5 it is unlikely that they will replace histologic tissue examination as the gold standard for postmortem diagnosis.
Applications of Cytology Techniques in Autopsy and Forensic Pathology Multiple cytodiagnostic techniques can be used during autopsy, providing rapid microscopic confirmation of macroscopic findings and facilitating more comprehensive provisional reporting to clinicians, legal investigators, and families of the deceased.1,2,4 Multiple studies have confirmed the usefulness of postmortem cytology in the diagnosis of benign and malignant neoplasms, as well as infectious and other non-neoplastic processes, with an overall 447
HELP DESK accuracy of 89%.2,6 Postmortem cytology may be of particular utility in those parts of the world where more sophisticated laboratory facilities are not readily available.2 However, there are some drawbacks inherent to postmortem cytology: a lack of tissue architecture may limit definitive diagnosis, and autolysis may result in poor preservation of cellular material, potentially resulting in misinterpretation.1,2 For solid tissue sampling, scrape cytology is recommended. The surface of the lesion in question is scraped with a clean scalpel blade, and the material obtained is smeared on a glass slide. Touch imprints can also be obtained. Slides are then either air-dried and stained with a rapid staining technique, such as Diff-Quik, or immediately fixed in 95% alcohol for later staining (Papanicolaou, hematoxylin and eosin, immunocytochemistry).1 Direct smears from postmortem lesions provide an adequate cell yield with preserved cytomorphology; the use of a rapid staining technique is technically simple and can be permanently sited in the autopsy room for use when needed.2,6 Fluid sampling with cytologic examination is another quick and inexpensive technique that can be useful in facilitating a rapid diagnosis at autopsy. For example, body cavity effusions may be aspirated before incision to avoid contamination because of leakage from other structures.1 Fluids obtained in this manner can then be processed by centrifugation and stained as described above, affording accurate assessment of malignant, infectious, or inflammatory processes. Cerebrospinal fluid (CSF) may be obtained through lumbar puncture, or direct cisternal puncture in the posterior fossa, or percutaneously. Cytologic evaluation of CSF and/or smears of brain tissue can be helpful in the diagnosis of inflammatory and neoplastic disorders. Postmortem urine samples can be obtained by suprapubic aspirate, puncture of exposed bladder, or from bladder washings. In addition to detecting bladder malignancies, urinary cytology is useful in the diagnosis of viral infection and renal disease. Bone marrow samples with well preserved cytomorphology can be obtained soon after death through sternal or iliac crest aspiration or can be squeezed from a resected rib. The obtained material can be smeared on slides or fixed in formalin for cell block preparation and further ancillary testing.1 Forensic investigations (including postmortem examination) of suspected sexual assault have been ever increasing in number. Because genital and/or anal injuries are infrequently detected by medical examination in these cases, the identification of semen by cytology and other methods is frequently relied on for confirmation of an alleged sexual assault.7,8 Spermatozoa can be recovered and cytologically identified in vaginal and anal swabs up to 72 and 24 hours postsexual assault, respectively; spermatozoa may even be recovered from skin and clothing in some cases.7 Although it provides 100% specificity, some pitfalls of semen detection by smear cytology include potential for spermatozoa fragmentation and only moderate sensitivity for detecting semen from individuals with low sperm counts.8 Rapid and sensitive assays for acid phosphatases and prostate-specific antigen can be used as adjuncts to cytology, because these assays tend not to be influenced by spermatozoa concentration.8 In the investigation of ballistic injuries, bullet wash cytology may provide supportive evidence of the trajectory of a bullet as it passes through the body and any intermediate targets. This technique can reliably recover inert material and tissue retained in the crevices of the bullet recovered from a body or shooting area that might otherwise go unnoticed or be lost through routine bullet cleaning after autopsy.1,9 In addition to trace evidence, such as
soot and clothing fibers, recoverable tissues from these projectiles often include cytologically recognizable skeletal and/or cardiac muscle revealing features of injury, such as fascicle separation or homogenization of cytoplasm or nuclear rupture. Projectiles entering the brain often have recoverable, intact microvascular structures in addition to neural, leptomeningeal, or scalp tissues.9 Friable tissues like liver and spleen are much less frequently recovered from bullet washings compared with more cohesive and elastic tissues. It is notable that high-velocity bullets tend to produce much more tissue fragmentation and less recoverable cellularity than their low-velocity counterparts. Nichols and Sens provide a comprehensive review of preparatory methods of bullet washing cytology together with abundant examples of recovered cells, tissues, and inert material.10
Conclusions In summary, various cytodiagnostic methods can be used in autopsy and forensic pathology investigations. Postmortem cytology provides for rapid confirmation of macroscopic findings, allowing for more comprehensive provisional reporting to clinicians, legal investigators, and decedents’ families. It likewise represents a viable alternative for obtaining diagnostic information when conventional autopsy is not feasible. Spermatozoa detection by smear cytology and bullet wash cytology are additional powerful methods for establishing key medicolegal evidence in forensic investigations.
FUNDING SUPPORT No specific funding was disclosed.
CONFLICT OF INTEREST DISCLOSURES The authors made no disclosures.
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Cacchione RN, Sayad P, Pecoraro AM, Ferzli GS. Laparoscopic autopsies. Surg Endosc. 2001;15:619-622.
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Roberts IS, Benamore RE, Benbow EW, et al. Post-mortem imaging as an alternative to autopsy in the diagnosis of adult deaths: a validation study. Lancet. 2012; 379:136-142.
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Walker E, Going JJ. Cytopathology in the post mortem room. J Clin Pathol. 1994; 47:714-717.
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Janisch S, Meyer H, Germerott T, Albrecht U-V, Schulz Y, Debertin AS. Analysis of clinical forensic examination reports on sexual assault. Int J Legal Med. 2010;124: 227-235.
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Khaldi N, Miras A, Botti K, Benali L, Gromb S. Evaluation of three rapid detection methods for the forensic identification of seminal fluid in rape cases. J Forensic Sci. 2004;49:1-5.
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Nichols CA, Sens MA. Cytologic manifestations of ballistic injury. Am J Clin Pathol. 1991;95:660-669.
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Nichols CA, Sens MA. Recovery and evaluation by cytologic techniques of trace materials retained on bullets. Am J Forensic Med Pathol. 1990;11:17-34. DOI: 10.1002/cncy.21562
Cytopathology Help Desk represents the opinions and views of the author and does not reflect any policy or opinion of the American Cancer Society, Cancer Cytopathology, or Wiley unless this is clearly specified.
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