Assessment of retraction in surgical specimens in melanoma patients submitted to oncological amplification of margins.

INTRODUCTION: Skin cancer is the most common type of cancer and represents more than half of the diagnosed malignant tumors. There are more than one million new cases per year in the United States and about 120.000 new cases in Brazil. Cutaneous melanoma represents 5% of all primary cutaneous neoplasms; however, it has a worse prognosis. Adequate treatment of the primary lesion is the main cure factor, with free surgical margins, thus avoiding recurrences of the lesion. OBJECTIVES: The present study aims to evaluate and quantify the retraction of the surgical specimen in three moments, in-vivo, ex-vivo and in-vitro, and also evaluating possible factors related to retraction, such as formalin fixation, age, patient's gender, and lesion location. METHODS: This is a prospective, single-center cohort that evaluated 145 surgical specimens from patients who underwent oncological surgery of cutaneous melanoma margins enlargement. Lesions were marked with a standard brush, and surgical margins were measured with a sterile ruler, according to their initial staging. After resection, new surgical specimens measurements were obtained, and, after fixation in formalin, the last measurement was performed. The same oncological surgeon performed all procedures, and the same pathologist analyzed the specimens. RESULTS: Regarding the area of the specimens, there was a general median retraction of 38.15% between in-vivo and ex-vivo (p < 0.001), and 43.97% between in-vivo and in-vitro. When the measure of the specimen length (L) was evaluated, there was a 17% retraction between in-vivo and ex-vivo, and 20.42% between in-vivo and in-vitro, with statistical significance. The younger population has a higher rate of retraction, and lesions on the back have a lower rate of shrinkage on the opposite of lower limbs that had higher shrinkage. DISCUSSION: Corroborating the literature, this study showed an average shrinkage of 20.42% for length measurements between in-vivo and in-vitro, and the main predictors of greater or lesser retraction were age and location of the lesion. It is also noted that the most considerable retraction occurs immediately after surgical resection, indicating that skin characteristics, such as degree of elasticity and tension, are determinant for the retraction. Formalin action does not significantly impact retraction. This study shows the importance of adequate treatment of the primary lesion, with adequate surgical margins, and that the measure measured by the pathologist, in general, represents 80% of the margins performed in the perioperative time.

Assessment of cell block technique in head and neck pathology diagnoses: A preliminary study.

OBJECTIVE: The head and neck region is a composite site made of multiple tissue components. These tissues when affected by disease or pathology present with an array of changes in the tissue architecture and pattern. It is essential to visualize the cellular details and tissue patterns for accurate diagnosis and treatment planning. Aspiration cytology primarily makes use of the cellular details for diagnosing lesions of the head and neck. Despite the promising results, its use is still limited in certain cases of the head and neck. The reason implicated could be the indiscernible appearance of cells in the absence of tissue integrity. In this regard, cell blocks are known to facilitate the visualization of the cytomorphological as well as the tissue arrangement patterns. Thus, the present study was designed to evaluate the role of cell block cytology in the diagnosis of various lesions of the head and neck. METHODS: Odontogenic lesions, epithelial carcinomas and connective tissue pathology of the head and neck origin were included in the study (n = 45). Aspiration cytology smears and cell block diagnosis were compared with tissue biopsy diagnosis for determining their sensitivity (%) and diagnostic efficacy. RESULTS: Cell blocks showed distinct preservation of the architectural pattern. In case of fluid-filled lesions, the contents were preserved and correlated with the tissue biopsy results. The results of cell blocks were similar to that of tissue biopsy in majority of the cases (95.56%). CONCLUSION: We recommend using cell blocks as a part of routine laboratory practice for all head-neck cases.

Stability validation of paraformaldehyde-fixed samples for the assessment of the platelet PECAM-1, P-selectin, and PAR-1 thrombin receptor by flow cytometry.

Sample fixation for storage and/or transportation represents an unsolved challenge for multicenter clinical trials assessing serial changes in platelet activity, or monitoring various antiplatelet regimens. Whole blood flow cytometry represents a major advance in defining platelet function, although special training and expensive equipment is required. We sought to determine how fixation with 2% paraformaldehyde (PFA), and storage of blood samples over 1 week affects the flow cytometry readings for both intact and thrombin-activating four major surface platelet receptors. Whole blood platelet expression of PECAM-1, P-selectin, PAR-1 inactive receptor (SPAN-12), and cleaved (WEDE-15) epitope was assessed immediately after blood draw, after staining with 2% PFA, and at day 1, 3, 5, and 7. The study was performed in 6 volunteers with multiple risk factors for vascular disease, not receiving any antiplatelet agents. Staining with PFA resulted in a slight decrease of fluorescence intensity, especially for PECAM-1, while antigen expression at day 1, 3 and 5 remains consistent, and highly reproducible. At day 7 there was a small but inconsistent trend towards diminished fluorescence intensity. The platelet data were consistent while validated with the isotype-matched irrelevant antibody. These data suggest that there is a 5 day window to perform final flow cytometry readings of whole blood PFA-fixed inactivated platelet samples. In contrast, thrombin activation cause gradual loss of flow cytometry signal, and cannot be recommended for long-term storage. This is critical logistic information for conducting multicenter platelet substudies within the framework of major clinical trials.

Cell block alone as an ideal preparatory method for hemorrhagic thyroid nodule aspirates procured without onsite cytologists.

OBJECTIVE: To study diagnostic efficacy of direct smears (DS) vs. cell block (CB) alone in hemorrhagic thyroid fine needle aspirations (FNAs) performed without a cytotechnologist or cytopathologist. STUDY DESIGN: Ultrasound-guided thyroid FNAs from an offsite location were retrospectively searched during a 53-month period. Aspirates in the initial 13 months were submitted as air-dried DSs. Subsequent specimens were submitted as CBs. Each case was classified into 1 of 4 categories: (1) nondiagnostic, (2) nonneoplastic, (3) follicular lesions and (4) papillary thyroid carcinoma (PTC). RESULTS: There were 77 aspirates: DS = 20 (26%) and CB = 57 (74%). Two cases had both DSs and CBs. Diagnoses of DS: nondiagnostic = 12 (60%); nonneoplastic = 7 (35%); follicular lesion = 1 (5%). Diagnoses of CB cases: nondiagnostic = 4 (7.0%); nonneoplastic = 43 (75.4%); follicular lesion, including 1 Hürthle cell neoplasm = 7 (12.3%), PTC = 3 (5.3%). Repeat FNAs on 4 nondiagnostic cases (3 DSs, 1 CB) utilizing the CB-only technique were diagnostic and included nodular goiter, follicular neoplasm, PTC, and reactive lymph node. CONCLUSION: Without onsite assessment, CB alone is superior to DSs for hemorrhagic thyroid FNAs. It shows increased diagnostic efficacy and slide reduction and obviates repeat FNAs.

In vivo experimentation with simian herpesviruses: assessment of biosafety and molecular contamination.

In vivo studies with highly pathogenic viruses prompt concerns regarding the persistence of infectious virus in pathology specimens. Although formalin fixation of tissues may inactivate infectious virus, fixation may also degrade viral nucleic acid and antigens, thereby limiting detection of virus in tissues by polymerase chain reaction (PCR) amplification or immunohistochemistry (IHC). We sought to: 1) assess the rate of inactivation of infectious virus in tissue specimens during formalin fixation, 2) assess IHC recognition of viral antigens and PCR detection of viral DNA after long-term (14 d) formalin fixation, and 3) investigate microtome contamination by DNA carry-over to subsequently sectioned tissues. Infectious baboon herpesvirus HVP2 could be recovered from fresh tissues of infected mice but not those fixed in formalin for >/=24 h. The intensity of IHC staining of viral antigen was unaffected by the duration of formalin fixation. PCR detection of viral DNA was negatively impacted by formalin fixation and/or heat inherent to paraffin processing; however, amplification of very short DNA sequences using real-time PCR was not affected. Lastly, microtome contamination by viral DNA was demonstrated by PCR screening of uninoculated control tissues that were sectioned after sectioning infected tissues. In summary, infectious virus is inactivated after only 24 h of formalin fixation whereas IHC staining remains sensitive in tissues fixed for up to 14 d. Formalin fixation does degrade DNA, but viral DNA can be detected by PCR amplification of very short DNA sequences. In addition, viral DNA can contaminate a microtome knife such that subsequently sectioned uninoculated control tissues exhibit false positive PCR amplification.

Assessment of specimen fixation in a surgical pathology service.

The quality of specimen fixation was examined within a routine diagnostic histopathology service. For each specimen the adequacy of fixation was assessed and the transit time between operating theatre and the laboratory was measured. Preliminary fixation was found to be inadequate in 25% of specimens and some form of manipulation to assist fixation was required in 36% of specimens. The mean transit time was 22 (SD 10.7) hours. Specimen fixation and transport are additional factors to consider in quality assurance of histopathology.