James E. Tate

PATHOBIOLOGY OF VULVAR SQUAMOUS NEOPLASIA

Vulvar squamous carcinoma is an uncommon neoplasm that afflicts a spectrum of women and has been associated with granulomatous vulvar diseases, papillomaviruses, and chronic inflammatory disorders of the vulva. Histopathological, molecular, and epidemiological studies have revealed two subsets of vulvar squamous neoplasia, which are distinguished by their association with human papillomaviruses and patient demographics. This review summarizes the evidence both supporting the diverse pathogenesis of these tumors and the existence of factors that may be common to both groups. Ultimately, the pathway to both human papillomavirus positive and negative vulvar cancers may involve not only obvious precancerous changes but also biological events in the vulvar mucosa that precede the onset of morphological atypia.

Viral and histopathologic correlates of MN and MIB-1 expression in cervical intraepithelial neoplasia

A recently studied tumor antigen, MN, has been associated with cervical carcinomas and cervical intraepithelial neoplasms (CIN), suggesting that it may serve as a marker for cervical cancer or cancer risk. To determine if expression of the MN antigen paralleled parameters reflecting viral or biological events in precursor epithelium, MN expression was correlated with MIB-1 expression, morphological phenotype, and human papillomavirus (HPV) distribution and type in a series of CINs. Seventy-three percent, 62% and 83% of CIN I, II, and III, respectively, were MN antigen positive. The proportion of neoplastic cells immunoreactive for MN did not correlate with the CIN grade or with HPV types stratified by their association with cancer. Evaluation of serial sections showed no correlation between the frequency of MN antigen staining, the proportion of MIB-1 immunoreactive cells, or the proportion of HPV positive cells detected by in situ hybridization (ISH). CINs associated with prototypical high risk (HPV 16) types exhibited increased immunostaining for the MIB-1 antigen and were more often classified as HSIL in contrast to the other types. Thus, although MN expression previously has been associated strongly with squamous carcinoma, it did not emerge as a specific marker for either cancer-associated HPV types or high grade CIN. CIN I lesions associated with low and high risk HPV types were not distinguished by MIB-1 expression and viral replication. This emphasizes the interrelationship between vegetative viral functions (including viral replication) and morphological phenotype, irrespective of HPV type.

Diagnosis of congenital syphilis from placental examination: Comparison of histopathology, steiner stain, and polymerase chain reaction for Treponema pallidum DNA

Congenital syphilis is often a presumptive diagnosis (based on serologies), because confirmation requires identification of Treponema pallidum in fetal/neonatal tissues or in the placenta. Placental histological features associated with congenital syphilis include the triad of enlarged hypercellular villi, proliferative fetal vascular changes, and acute or chronic villitis. The authors blindly evaluated 49 formalin-fixed, paraffin-embedded placentas (38 with positive maternal syphilis serologies; 11 with negative serologies) and compared results of histology, Steiner stain, and polymerase chain reaction (PCR) for T pallidum DNA. Histology was categorized as positive (triad present), suspicious (two thirds of triad present), or negative. Treponemal DNA was detected by amplifying a 189 base pair region of the 47 kd treponemal membrane antigen with 44 cycles of PCR; products were detected by Southern blot. Placentas from the 11 seronegative mothers were all negative by histology, Steiner stain, and PCR. Among the 38 placentas from serologically positive mothers, 4 had positive histology (2 of 4 positive Steiner, 4 of 4 positive PCR); 6 had suggestive histology (0 of 6 positive Steiner; 1 of 6 positive PCR); and, 28 had negative histology (0 of 28 positive Steiner; 1 of 28 positive PCR). PCR identification of treponemal DNA was significantly associated with the triad (P = .0003), proliferative fetal vascular changes (P = .0003), acute villitis (P = .003), chronic villitis (P = .004), and spirochetes on Steiner stain (P = .01). These results (1) confirm a strong association between placental histopathologic features and congenital syphilis; (2) indicate that when such features are present, PCR of placental tissue may confirm the diagnosis of congenital syphilis; and (3) suggest that even when such features are absent, PCR of placental tissue may identify additional cases of histologically unsuspected congenital syphilis.

Absence of papillomavirus DNA in normal tissue adjacent to most cervical intraepithelial neoplasms.

Objective To determine if human papillomavirus (HPV) DNA is present in the normal mucosa adjacent to cervical intraepithelial neoplasia (CIN). Methods Serial sections of 28 CIN lesions were studied. Lesional and normal epithelia and stroma were microdissected; the DNA was extracted and amplified by polymerase chain reaction (PCR) using primers designed to amplify both HPV late (L1) and human beta-globin sequences. Human papillomavirus was typed by restriction fragment length polymorphism analysis following digestion of PCR products. Results Twenty-five of 28 (89%) lesional epithelia scored positive for HPV nucleic acids. In four of 25 (16%) HPV-positives, the normal squamous epithelium scored positive for HPV nucleic acids, two of which (8%) also scored positive in the stroma. Repeat microdissection and PCR analysis of three of these cases was performed and all were negative in both normal epithelium and stroma, suggesting laboratory contamination. Conclusion Human papillomavirus nucleic acids are present uncommonly in normal-appearing squamous epithelium adjacent to CIN. This does not exclude occult infection in the natural history of CIN but indicates that when lesions develop, occult infection is not normally maintained in the normal mucosa. This is consistent with the low recurrence rates following ablation as well as low indices of HPV positivity in normal cervices during followup. This finding should be taken into consideration when counseling patients and is relevant to the concept of HPV testing during follow-up after cone biopsy.

Disparities in mean age and histopathologic grade between human papillomavirus type-specific early cervical neoplasms

Noninvasive squamous and glandular precursor lesions associated with human papillomavirus (HPV) types 16 and 18 have been reported to vary in morphology. HPV 16 is associated predominantly with high-grade squamous intraepithelial lesions (HSIL; cervical intraepithelial neoplasia (CIN 2 and 3), and HPV 18 is associated with low-grade squamous intraepithelial lesions (condyloma/CIN 1) and CIN 3/adenocarcinoma in situ (ACIS). This study explored the relationship of morphologic growth pattern in these precursor groups with age of presentation. One hundred fourteen CIN lesions (including those with ACIS), associated with HPV 16 or 18, were subdivided into well-differentiated low- and high-grade SIL (CIN 1 and 2, respectively), poorly differentiated HSIL (CIN 3) with or without ACIS. HPV was detected by polymerase chain reaction (PCR) amplification with L1 consensus or type-specific E7 primers and typed by restriction fragment length polymorphism (RFLP) analysis. Age of the patient was obtained from the pathology report. Mean age for each group was as follows: Low-risk HPVs, 25 years; HPV 18 CIN 1-2, 21.6 yrs; HPV 18 CIN 3/ACIS, 35.2 yrs; HPV 16 CIN 1,2, 25.9 yrs; and HPV 16 CIN 3, 29.8 yrs. There were significant differences in mean ages between HPV 18 CIN 1 and 2 and HPV 16 CIN 1 to 2 (P = .04), HPV 16 CIN 1-2 and CIN 3 (P = .01) and HPV 18 CIN 1 to 2 and HPV 18 CIN 3/ACIS (P = .00001). None of the cases of HPV 18-associated CIN3/ACIS was associated with a CINI lesion. The disparity in mean ages between well and poorly differentiated HPV 16/18 related that precursor lesions could reflect factors such as morphologic progression with increasing age, different rates of lesion persistence, depending on grade, or efficiency of detection between the two groups. The marked difference in mean age between HPV 18-associated CIN 1-2 and CIN 3/ACIS, combined with their lack of coexistence in the same cervix, raises alternate possibilities that specific viral or host factors may determine the morphological phenotype associated with some HPV 18 infections. In the latter, the possibility that age independently confers an increased risk for higher-grade lesions should be considered.