Conventional in situ hybridization (CISH) can be used for detection of human papillomavirus (HPV) DNA, enabling preservation of the tissue morphology and assessment of the physical state of viral DNA, but has low sensitivity. This study compared the sensitivity and efficiency of in situ hybridization with tyramide signal amplification (ISH TSA) with those of CISH. The HPV status of 77 cases with early stage cervical carcinoma was evaluated with CISH, using biotinylated probes for HPV types 6/11, 16/18 and 31/33/51, and with ISH TSA using probes for HPV types 6/11, 16/18 and 31/33 or 31/33/51. The HPV DNA was detected in 26 (33.8%) cases using CISH, and in 45 (58.4%) cases using ISH TSA. By adding the TSA step, the sensitivity of CISH was enhanced by 24.7%, thus enabling detection of 20 new HPV-positive cases. Multiple HPV infections were detected in four cases. A dot signal pattern was present in 68.9% (31/45) and more than five positive nuclei per sample were found in 82.2% (37/45) of the cases. We found that the ISH TSA system is a fast and simple method for detection of HPV DNA in cervical carcinoma compared to CISH, and is more sensitive and efficient in the detection and typing of HPV, assessment of HPV DNA physical state and evaluation of the number of positive cells than CISH.

Molar pregnancy is a gestational trophoblastic disease that belongs to the category of precancerous lesions. On the other end of the spectrum are gestational trophoblastic neoplasms such as invasive mole, choriocarcinoma, placental site trophoblastic tumor and epithelioid trophoblastic tumor, which are considered malignant tumors. Based on defined histopathological criteria, molar pregnancy is divided into partial and complete hydatidiform mole. Especially in the case of early complete mole, the diagnosis can be quite challenging and often necessitates additional molecular or immunohistochemical methods. The aim of this study was to assess the importance of additional molecular and immunohistochemical methods to accurately diagnose complete hydatidiform mole and to stress the importance of correct diagnosis and close follow-up of these patients. A total of 367 consecutive cases of spontaneous abortion were analyzed in a 3-year period. Eight cases with histopathological diagnosis of complete molar pregnancy were selected for further analysis. Apart from standard microscopic analysis, additional molecular and immunohistochemical analyses were performed in all eight cases. Most of the histopathological characteristics of complete molar pregnancy were present in all cases, together with complete absence of positivity for the p57 immunohistochemical marker in the cytotrophoblasts and villous stromal cells. The molecular analysis revealed androgenetic diploidy in seven cases and biparental diploidy in one case with more than three consecutive complete molar pregnancies. Additional immunohistochemical and molecular methods can considerably aid in the correct diagnosis of molar pregnancy.