Signet ring morphology is recognized throughout the gastrointestinal tract. However, this pattern may be observed in other primary sites giving rise to diagnostic challenges in the work-up of metastases. Relatively newer immunohistochemical markers have not been evaluated in this context. We assessed expression patterns of several common immunohistochemical markers in tumors with Signet ring morphology to delineate a pragmatic approach to this differential diagnosis. Primary breast and gastrointestinal carcinomas showing Signet ring features were reviewed. Non-mammary and non-gastrointestinal tumors with this morphology were included for comparison. Estrogen receptor (ER), progesterone receptor (PR), E-cadherin, CK7, CK20, GCDFP-15, mammaglobin, CDX2, GATA-3, and HepPar-1 immunohistochemistry was performed. Expression patterns were compared between breast and gastrointestinal tumors as well as lobular breast and gastric tumors. Ninety-three cases were identified: 33 breast carcinomas including 13 lobular, 50 gastrointestinal tumors including 23 gastric, and 10 from other sites. ER (sensitivity=81.8%, specificity=100%, positive predictive value (PPV)=100%, negative predictive value (NPV)=89.3%) and GATA-3 (sensitivity=100%, specificity=98%, PPV=96.8%, NPV=100%) expression were associated with breast origin. CK20 (sensitivity=66.7%, specificity=93.3%, PPV=94.1%, NPV=63.6%) and CDX2 (sensitivity=72%, specificity=100%, PPV=100%, NPV=68.9%) demonstrated the strongest discriminatory value for gastrointestinal origin. These markers exhibited similar discriminatory characteristics when comparing lobular and gastric signet ring carcinomas. In a limited trial on metastatic breast and gastric cases, these markers successfully discriminated between breast and gastric primary sites in 15 of 16 cases. ER and GATA-3 are most supportive of mammary origin and constitute an effective panel for distinguishing primary breast from primary gastrointestinal Signet ring tumors when combined with CK20 and CDX2 immunohistochemistry.

Objective: A vast majority of cervicovaginal intraepithelial lesions are caused by high-risk human papillomaviruses (HPVs). The Pap test has been the sole method used for the screening of cervicovaginal squamous intraepithelial lesions (SIL). Recently, the FDA approved an HPV-DNA assay as a method of primary screening. We report on a series of FDA-approved HPV-DNA test-negative SIL with HPV genotyping, using an alternative method on the corresponding surgical biopsy specimens. Study Design: A retrospective review identified cytology-positive HPV-negative cases over a 15-month period at a tertiary care gynecologic oncology institution. Corresponding biopsies were reviewed and genotyped for high-risk HPVs. Results: Of the 18,200 total cases, 17 patients meeting the study criteria were selected with 27 surgical specimens corresponding to their cytologic diagnoses. Four patients with high-grade lesions were identified, 3 of whom (75%) were positive for HPV. One of these 4 patients (25%) showed high-grade SIL on biopsies from 4 separate sites in the cervix and vagina. Multiviral HPV infections were frequent. Conclusions: We discuss the relevance of cotesting for screening cervical SILs and emphasize that false-negative results are possible with the FDA-approved HPV screening assay, also in patients with high-grade SIL. These cases may be detectable by cytologic examination and this suggests that the Pap test remains an important diagnostic tool.

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N Context.-Acute hypotensive transfusion reactions are potentially harmful adverse effects of transfusion attributable to bradykinin generation. They are most often seen in patients taking angiotensin-converting enzyme (ACE) inhibitors (ACE-Is) because of the role ACE plays in metabolizing bradykinin. However, a number of acute hypotensive transfusion reactions occur in patients not taking ACE-Is. Aminopeptidase P (APP), another important enzyme responsible for bradykinin degradation, is encoded by the polymorphic XPNPEP2 gene. Some polymorphisms in XPNPEP2 have been associated with decreased APP activity. However, the role that APP polymorphisms play in acute hypotensive transfusion reactions has never been investigated.Objective.-To develop a molecular assay to examine for the C-2399A single-nucleotide polymorphism (SNP) in the APP gene, XPNPEP2, in patients experiencing acute hypotensive transfusion reactions unassociated with ACEIs.Design.-We developed an assay using polymerase chain reaction and DNA sequencing with primers targeted at XPNPEP2 (59-GAGTATTATGTGGGGACCATCC-39 and 59-ATGCCTCGCAGAGACAAGAG-39). Polymorphism zygosity was determined by comparing the sense/antisense sequencing results. This assay was then applied to patients with acute hypotensive transfusion reactions not taking ACE-Is (n = 4).Results.-A C-2399A SNP assay was successfully developed and applied to patients with acute hypotensive transfusion reactions. In a pilot study, 2 patients (50%) were found to possess C-2399A polymorphisms. One was found to be homozygous, and the other was heterozygous.Conclusions.-Our C-2399A SNP assay can be used to study acute hypotensive transfusion reactions in patients not taking ACE-Is. Initial data indicate that the C-2399A polymorphism may be a contributing factor in such reactions. However, further studies are necessary to better define the role of APP polymorphisms in relation to acute hypotensive transfusion reactions unassociated with ACEIs.(Arch Pathol Lab Med. 2013;137:96-99; doi: 10.5858/ arpa.2011-0466-OA) A cute hypotensive transfusion reactions are relatively rare, but potentially serious adverse events in which a transfusion recipient manifests a marked decrease in blood pressure with a virtual absence of other signs and symptoms.1,2 Much of the pathophysiology of acute hypotensive transfusion reactions has been linked to bradykinins and their metabolites, mediators that can induce substantial vasodilation and smooth muscle relaxation in vivo, with a resultant decrease in blood pressure.3 Some studies have also shown that bradykinin accumulation and hypotensive episodes may be exacerbated in transfused patients taking angiotensin-converting enzyme (ACE) inhibitors (ACE-Is), because ACE is a key enzyme in the degradation of bradykinin.3-11 However, based on reports of acute hypotensive transfusion reactions occurring in the absence of ACE-I use, 5,12 it is possible that other pathways may contribute to the accumulation of bradykinin and/or their metabolites and result in hypotension in the se...

Angiosarcomas are rare malignancies arising from cells of endothelial origin and are aggressive sarcomas that can occur in any anatomic site. They are reported to have predilection for the scalp, extremities and breasts. The incidence of these tumors is increasing, which has been suggested to be attributable to the growing use of radiotherapy to treat breast and other malignancies. There is currently limited literature describing the primary cytologic diagnosis of angiosarcoma on fine needle aspirate material. We describe the findings of three cases of angiosarcoma diagnosed by fine needle aspiration. Our three cases offer distinct radiologic, clinical and cytopathologic points-of-view: a thyroid angiosarcoma, a mediastinal angiosarcoma and a skin angiosarcoma. The cytomorphology of angiosarcoma is characterized by large highly atypical spindle to epithelioid cells with abundant cytoplasm in dispersed single cells or loose aggregates. The nuclei are large and pleomorphic with vesicular chromatin and prominent nucleoli. Mitoses are readily identified. The background can be bloody and/or necrotic. Occasional intracytoplasmic lumens are a helpful morphologic feature suggesting vascular differentiation. HHV-8 immunostaining may aid in the differential diagnosis with Kaposi sarcoma while epithelioid hemangioendothelioma can be distinguished based on morphologic features. Given the metastatic potential and high mortality rate associated with these tumors, this entity is an important consideration in the contexts herein described.

Routine histopathologic examination of hemorrhoidectomy specimens is controversial having been described as not useful and expensive with few of these common cases demonstrating incidental lesions. However, unexpected premalignant and malignant lesions have been detected on excised hemorrhoids. The high-risk human papillomavirus (HR-HPV) types associated with these incidentally identified high-grade lesions are presently unknown. We aimed to identify cases of incidental high-grade anal intraepithelial neoplasia (HG-AIN) and anal squamous cell carcinoma incidentally discovered on hemorrhoidectomy specimens, genotype HR-HPVs from these lesions, and assess p53 and p16 expression by immunohistochemistry to identify risk factors for their development. With institutional approval, cases with associated demographics from 1995 to 2015 were reviewed to identify and confirm incidental HG-AIN or squamous cell carcinoma in hemorrhoidectomy specimens. Genotyping for HR-HPV types and immunohistochemical staining for p53 and p16 was performed. Statistical analysis comparing HPV genotypes, p53 and p16 staining, and potential risk factors by the Fisher exact test was performed. In the largest series of incidental high-grade lesions on hemorrhoidectomy, HPV 16 was the most common HR-HPV detected though multiple-type infections were common including some HPV 16/18-negative cases. By genotyping, HPV 39 was significantly associated with IV-drug abuse history (P=0.0015) and HIV-positive status (P=0.037), whereas HPV 58 detection correlated with chemotherapy-induced immunosuppression (P=0.029). There was frequent overlap between p53 staining and HPV positivity, particularly when HPV 31 was detected. We also identified several mimickers of HG-AIN that may present diagnostic challenges in these specimens. Our data support continued routine examination of hemorrhoidectomy specimens and suggest that adjunctive studies such as immunohistochemistry for challenging cases may be useful.

Focal micropapillary features in invasive urothelial carcinoma is sometimes difficult to distinguish from retraction artifact morphologically. Cell polarity reversal has been demonstrated in micropapillary tumors by epithelial membrane antigen (EMA) immunostaining. We have previously described the use of E-cadherin as a cell polarity marker in ovarian micropapillary serous borderline tumors. The aim of this study was to evaluate the utility of immunohistochemistry for EMA and E-cadherin in differentiating micropapillary urothelial carcinoma from retraction artifact. We identified 29 invasive urothelial carcinomas with micropapillary features and 30 invasive urothelial carcinomas without reported micropapillary features but with areas of retraction artifact. Cell polarity reversal was considered present if E-cadherin showed membranous apical cup-like staining or if EMA demonstrated a well-defined basal staining towards the stroma. Twenty-seven of 29 cases (93%) of urothelial carcinoma with micropapillary features demonstrated EMA or E-cadherin staining patterns consistent with cell polarity reversal. Staining consistent with micropapillary architecture was identified with both markers in 20 of these 27 cases (74%). Six cases showed reversal of polarity by E-cadherin alone, whereas 1 case showed polarity reversal by EMA alone. Retraction artifacts showed circumferential staining by E-cadherin and lacked well-defined basal staining by EMA. Three cases originally classified as with retraction artifact showed reversal of cell polarity by both EMA and E-cadherin and were reclassified as micropapillary. Our data show that pathologists can reliably make this distinction in most cases. However, in some cases with ambiguous features, EMA and E-cadherin immunostaining may aid in resolving this diagnostic dilemma.

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