Diagnostic utility of p57 immunohistochemistry and DNA ploidy analysis by fluorescence in situ hybridisation in hydatidiform moles.

INTRODUCTION: Hydatidiform moles (HMs) include complete and partial moles, are the result of abnormal fertilisation. The accurate classification of HMs and its distinction from non-molar specimens is utmost important for clinical management and risk assessment. It is diagnostically challenging if the distinction is based solely on histomorphology with poor interobserver reproducibility, especially in early gestations. This study aimed to investigate the diagnostic ability of combined p57 immunohistochemistry and DNA ploidy analysis to distinguish between complete moles, partial moles and non-molar abortus. MATERIALS AND METHODS: We included all HMs cases diagnosed in our centre over a six-year period. p57 immunohistochemistry stain was performed. Only nuclear immunoreactivity in >50% of cytotrophoblasts and villous stromal cells was regarded as positive for p57. DNA ploidy status was determined by fluorescence in situ hybridisation. A total of 250 cells from five chorionic villi were counted and were scored as diploid or triploid if more than 10% of nuclei demonstrated two or three signals, respectively. RESULTS: A total of 51 cases originally diagnosed by histomorphology as complete mole (n = 18), partial mole (n = 24) and non-molar abortus (n = 9) were recruited. The cases were reclassified based on the p57 immunostaining pattern and DNA ploidy status, into 27 complete moles (p57-/diploid), 9 partial moles (p57+/triploid) and 15 non-molar abortus (p57+/diploid). The diagnostic accuracy by histomorphological features alone in each category: complete moles, partial moles and non-molar abortus was 78.4%, 70.6% and 88.2% respectively. CONCLUSION: This study highlighted the importance of the utility of combined p57 immunostain and DNA ploidy analysis in arriving at an accurate diagnosis in HMs. An algorithmic approach utilising these ancillary techniques is advocated in routine diagnostic workup for a more refined diagnostic approach to HMs.

Primary extragonadal vaginal yolk sac tumour: A case report.

INTRODUCTION: Yolk sac tumour (YST) or endodermal sinus tumour is rare and typically seen in gonads. CASE REPORT: We described a case of extragonadal vaginal YST in a one year and seven months old girl who presented with vaginal discharge and bleeding, and discuss its differential diagnosis and potential pitfalls in immunohistochemistry. She was found to have a suprapubic mass on examination. The serum alpha fetoprotein was 11919.4 ng/mL. Computed tomography of the pelvis revealed a large 6.4 cm heterogenous pelvic mass. Colposcopic examination of the pelvis showed a fungating vaginal mass that was subsequently confirmed as a yolk sac tumour. Immunohistochemically, the malignant cells were positive toward CKAE1/AE3, AFP and glypican-3, as well as CD117. DISCUSSION: Solid pattern extragonadal vaginal YST may morphologically resemble dysgerminoma that is also CD117 positive, while the glandular pattern YST may have clear cytoplasm and is positive for cytokeratin; hence, may resemble clear cell carcinoma. Being mindful of these potential diagnostic caveats is necessary to prevent misdiagnosis.

Cyclical elongation regulates contractile responses of isolated airways.

Bronchoconstrictor responses are quantitatively different when they are evoked under static conditions and during or after periods of deep inspiration. In vivo, deep inspirations produce bronchodilation and protect the lung from subsequent bronchoconstriction (termed bronchoprotection). These effects may be due in part to dynamic stretch on airways produced by cyclical expansion of airway diameter. However, airways also lengthen cyclically during breathing. The effects of cyclical airway elongation on evoked bronchoconstriction have not been examined. This study recorded evoked contractions of pig bronchial segments 1) at different airway lengths, 2) after a period of cyclical lengthening in relaxed airways, and 3) during cyclical lengthening in pretoned airways. Airway segments were mounted in organ baths and bathed in Krebs solution luminally and on the adventitia. Airways were cyclically lengthened by 5-30% of their deflated length at 0.5-2 Hz for 5 min. Contractions were evoked by electrical field stimulation or carbachol and were recorded under isovolumic conditions. Under static conditions, there was a blunt relationship between length and response to electrical field stimulation. After a period of airway length cycling, electrical field stimulation-induced contractions were increased. In airways pretoned with carbachol, cyclical lengthening produced a transient bronchodilation and a sustained increase in contraction. Contractile responses were not blocked by indomethacin. The results show that isolated airways respond actively to dynamic changes in length. Our results indicate that cyclical lengthening of airways could contribute to lung function in vivo but does not appear to account for the phenomenon of bronchoprotection.