Extraneural sclerosing perineurioma of the buccal mucosa: a case report and clinicopathologic review.

The perineurioma is an infrequently encountered benign peripheral nerve sheath tumor composed of a clonal proliferation of perineurial cells. Rare cases of perineurioma have been reported in the oral cavity. An extraneural sclerosing perineurioma arising in the buccal mucosa of a 17-year-old male is presented. Histopathologically, the tumor is composed of a well circumscribed nodular proliferation of spindle cells arranged in a storiform growth pattern, in some areas subtly arranged around vascular channels. The tumor cells reveal positive immunostaining for epithelial membrane antigen (EMA), collagen type IV and vimentin, and negative immunostaining for S-100 protein, consistent with a perineurial origin. To the best of our knowledge, this case represents the first report of an extraneural sclerosing perineurioma involving the oral cavity.

Clinical and pathologic features of ductal carcinoma in situ associated with the presence of flat epithelial atypia: an analysis of 543 patients.

Flat epithelial atypia is an alteration of mammary terminal duct lobular units that is considered to be a precursor to, or early stage in, the development of some forms of ductal carcinoma in situ. No prior study has systematically evaluated the relationship between various clinico-pathologic features of ductal carcinoma in situ and the presence of coexistent flat epithelial atypia. An understanding of such relationships could provide insight into the connection between flat epithelial atypia and ductal carcinoma in situ. We reviewed slides from 543 ductal carcinoma in situ patients enrolled in a case-control study assessing epidemiologic and pathologic risk factors for local recurrence. We examined the association between the presence of flat epithelial atypia and various clinical factors, pathologic features of the ductal carcinoma in situ, and the presence of coexistent atypical ductal hyperplasia, lobular neoplasia, and non-atypical columnar cell lesions. In univariate analysis, the presence of flat epithelial atypia was significantly related to ductal carcinoma in situ nuclear grade (most common in low grade, least common in high grade; P<0.0001), architectural pattern (most common in micropapillary and cribriform, least common in comedo; P<0.0001), absence of comedo necrosis (P<0.001), absence of stromal desmoplasia (P=0.02) and absence of stromal inflammation (P=0.03). In multivariable analysis, features of ductal carcinoma in situ independently associated with flat epithelial atypia were micropapillary and cribriform patterns and absence of comedo necrosis. Additionally, flat epithelial atypia was significantly associated with the presence of atypical ductal hyperplasia, lobular neoplasia, and columnar cell lesions in both univariate and multivariable analyses. These observations provide support for a precursor-product relationship between flat epithelial atypia and ductal carcinoma in situ lesions that exhibit particular features such as micropapillary and cribriform patterns and absence of comedo necrosis.

Superficial (early) endocervical adenocarcinoma in situ: a study of 12 cases and comparison to conventional AIS.

Although established histologic criteria for the diagnosis of endocervical adenocarcinoma in situ (AIS) have been published, some lesions are not readily classified or present with more subtle degrees of epithelial atypia. Lesions confined to the surface mucosa may be particularly challenging, possibly because they represent early disease. Twelve cases of superficial AIS (SAIS) confined to the surface mucosa or crypt openings culled from the in-house and consultation practices were examined histologically, immunostained for MIB-1 and p16, and analyzed (when possible) for HPV nucleic acids by DNA-DNA in situ hybridization (INFORM). The mean age was 26.7 years for SAIS versus 37.0 years for 42 consecutive cases of conventional AIS from the same practice (P < 0.001). Seven and five were biopsies and conization specimens, respectively. Five coexisted with CIN, four arose in endocervical papillae, and two arose in endocervical polyps. Nuclear hyperchromasia was conspicuous in 10 and mitoses were present in all; however, apoptosis was rare or absent in four, and six exhibited only mild nuclear atypia. Mib-1 staining exceeded 40% in 5 of 7 cases tested, and all (8 of 8) were strongly positive for p16(ink4). Five of five were positive for HPV by ISH with an "integrated" dot-like pattern. SAIS is an early variant of AIS that 1) occurs at a younger mean age, 2) exhibits variable atypia, and 3) arises adjacent to morphologically normal columnar epithelium. Diffuse p16 expression and integrated HPV pattern are identical to that seen in more extensive forms of the disease. Superficial AIS should be suspected in endocervical columnar epithelium with segmental nuclear hyperchromasia with mitotic activity, and confirmed by biomarker staining (p16 and Mib-1) if the pathologist is uncertain of the diagnosis.

Prospective evaluation of AMACR (P504S) and basal cell markers in the assessment of routine prostate needle biopsy specimens.

Distinguishing benign prostate glands from malignant ones, based purely on morphology, on prostatic core needle biopsy specimens (PNBs) may prove difficult, particularly if the suspicious focus is small. In recent years, several immunohistochemical markers, including the basal cell cocktail (BCC), 34betaE12 and p63, and the prostate cancer (PCa) biomarker alpha-methylacyl-CoA-racemase (AMACR), have been used as adjuvants to morphology, in these diagnostically challenging cases. We prospectively address the diagnostic utility of using the BCC, in combination with the commercially available AMACR monoclonal antibody, P504S, on PNBs that required immunohistochemistry (IHC) studies to make a diagnosis. The goals of this prospective study were to assess the day-to-day practice in an academic setting, to determine how often these IHC tests were used on routine PNBs, and to establish how often a combination of the BCC and P504S were helpful in diagnosing prostate cancer. A total of 772 prospectively collected PNB cases were examined over a 7-month period. IHC staining was performed in 171 cases (22%); 123 cases were stained with the BCC in addition to the commercially available monoclonal AMACR antibody. In 86 of these 123 cases (70%), both stains contributed to the final diagnosis: PCa in 44 cases, benign in 33 cases and high-grade prostatic intraepithelial neoplasia in 9 cases. Of the remaining 37 cases (30%), 18 were called benign or PCa, based solely on appropriate staining with the BCC, with AMACR being noncontributory because the focus of interest had been cut through (12 cases), there was negative staining with AMACR (in 4 PCa cases), or there was positive staining with AMACR (in 2 benign cases showing atrophy). Nineteen of 37 cases were diagnosed as atypical small acinar proliferation. In these 19 cases either the focus had been cut through on one or both of the stains (11 cases), both AMACR and BCC failed to work (2 cases), AMACR was positive in the presence of patchy BCC staining (1 cases), AMACR was negative in the absence of BCC staining (3 cases), or despite appropriate staining the focus consisted of 1 gland and was considered too small to call carcinoma (2 cases). Additional IHC stains were performed in 171 of 772 cases; of these, 123 had sufficient material to perform both the BCC and P504S. The BCC when used in combination with AMACR rendered a diagnosis in almost 70% of cases. Using these stains in combination may be a better approach in diagnostically difficult cases as it increases the likelihood that a definitive diagnosis can be rendered while decreasing the likelihood of an equivocal diagnosis. However, a limitation of this approach is the loss of tissue in these small lesions, suggesting that combining AMACR and the BCC on a single slide would be superior to using either marker separately.