Most, but not all, cervical adenocarcinomas of usual type contain HPV, but those of unusual morphological type are almost always HPV-negative. This has implications for the efficacy of HPV vaccination in the prevention of cervical adenocarcinoma. A significant proportion of cervical adenocarcinomas are p16-positive in the absence of HPV, illustrating that in these neoplasms diffuse p16 immunoreactivity is not a reliable surrogate marker of the presence of high-risk HPV.

Typical squamous elements and morules have an overlapping but differing immunophenotype. Morules exhibit no firm immunohistochemical or ultrastructural evidence of squamous differentiation, although immature squamous differentiation cannot be excluded. Nuclear beta-catenin positivity is in keeping with the observation that endometrioid glandular lesions with morules are often associated with beta-catenin gene mutation. The explanation for diffuse nuclear positivity with the intestinal transcription factor CDX2 in morules is not clear, but may be a result of overexpression of nuclear beta-catenin. We suggest that the term morular metaplasia is used instead of squamous morules.

p63 plays a key role in epithelial development in various organs, being expressed in myoepithelial cells and in basal cells of stratified epithelia. In the female genital tract, p63 is expressed in the basal and parabasal cells of mature cervical, vaginal and vulval squamous epithelium, and also in cervical reserve cells at the transformation zone and in immature metaplastic and atrophic cervical squamous epithelium. In this review, the diagnostic utility of p63 immunohistochemical staining in various pathologic scenarios within the female genital tract is discussed. Cervical microglandular hyperplasia is p63 positive with a characteristic subcolumnar location due to expression in reserve cells. There is increased expression in cervical intraepithelial neoplasia, in accordance with the degree of dysplasia. One of the most useful applications of p63 is in the evaluation of problematic cervical carcinomas; most squamous carcinomas exhibit diffuse nuclear immunoreactivity whereas most adenocarcinomas and neuroendocrine carcinomas are negative or focally positive. In conjunction with neuroendocrine markers, p63 is useful in distinguishing between a squamous carcinoma and a small cell or large cell neuroendocrine carcinoma. In the normal endometrium, a population of p63-positive cells is present which may act as a stem cell population and which is increased in various forms of metaplasia. Placental site nodule and epithelioid trophoblastic tumor (lesions derived from chorionic-type intermediate trophoblast) are usually p63 positive whereas placental site reaction and placental site trophoblastic tumor (lesions derived from implantation site intermediate trophoblast) are usually negative; thus, p63 may be useful in the diagnostic algorithm of trophoblastic lesions. p63 positivity in ovarian epithelial tumors is uncommon and largely restricted to squamous and transitional neoplasms, including benign and borderline Brenner tumor. p63 is also positive in cervical transitional metaplasia, Walthard rests, vulval Paget disease secondary to an underlying urothelial malignancy, tubulosquamous polyp of the vagina, and ectopic prostatic tissue in the cervix.

Sarcoma is a rare disease affecting both bone and connective tissue and with over 100 pathologic entities, differential diagnosis can be difficult. Complementing immunehistological diagnosis with current ancillary diagnostic techniques, including FISH and RT-PCR, can lead to inconclusive results in a significant number of cases. We describe here the design and validation of a novel sequencing tool to improve sarcoma diagnosis. A NGS DNA capture panel containing probes for 87 fusion genes and 7 genes with frequent copy number changes was designed and optimized. A cohort of 113 DNA samples extracted from softtissue and bone sarcoma FFPE material with clinical FISH and/or RT-PCR results positive for either a translocation or gene amplification was used for validation of the NGS method. Sarcoma-specific translocations or gene amplifications were confirmed in 110 out of 113 cases using FISH and/or RT-PCR as gold-standard. MDM2/CDK4 amplification and a total of 25 distinct fusion genes were identified in this cohort of patients using the NGS approach. Overall, the sensitivity of the NGS panel is 97% with a specificity of 100 and 0% failure rate. Targeted NGS appears to be a feasible and cost-effective approach to improve sarcoma subtype diagnosis with the ability to screen for a wide range of genetic aberrations in one test. tissue samples that have previously been characterized by FISH or RT-PCR in clinical laboratories. Methods Ethics approval and consent to participate Local approval was obtained for the molecular analysis of all clinical material in this study according to standard clinical practice.