Herpes Zoster Presenting As Cutaneous Vasculitis in the Upper Extremity.

The varicella-zoster virus (VZV), a member of the Herpesviridae family (HHV-3), is the pathogen responsible for causing herpes zoster, the skin eruption known as shingles. This report describes a rare presentation of herpes zoster involving cutaneous vasculitis in the unilateral upper extremity in an immunocompetent patient. Histologic evaluation confirmed a diagnosis of leukocytoclastic vasculitis and yielded a positive VZV immunoperoxidase stain. An approach to histologic evaluation of this case is discussed.

Inflammatory dermatoses of the vulva.

Inflammatory, non-neoplastic epidermal alterations of the vulva can be correctly diagnosed using classification schemes applied to skin elsewhere on the body. A wide range of inflammatory disorders may occur on the vulva, and they may have a similar clinical presentation to HPV lesions. However, HPV is incurable and often is treated surgically. Accordingly, as inflammatory dermatoses commonly occur on the vulva and are often curable with topical therapy, an awareness of these entities and an ability to distinguish them from HPV are imperative.

Latency-associated nuclear antigen expression and human herpesvirus-8 polymerase chain reaction in the evaluation of Kaposi sarcoma and other vascular tumors in HIV-positive patients.

Human herpesvirus-8 (HHV-8) latency-associated nuclear antigen (LANA) is expressed in endothelial and spindle cells of nearly all Kaposi sarcomas, and the presence of this antigen in serum is strongly correlated with the risk of developing Kaposi sarcoma in immunocompromised individuals. Studies of vascular tumors occurring in the general population show LANA expression to be specific for Kaposi sarcoma. No study to date, however, has examined whether non-Kaposi sarcoma vascular tumors arising in immunocompromised patients may express LANA, possibly reflecting origin from an HHV-8-infected endothelial progenitor cell. The objective of this study was to evaluate the specificity of LANA expression for Kaposi sarcoma in immunocompromised patients by LANA immunohistochemistry and real-time polymerase chain reaction (PCR) for HHV-8. A total of 13 cases of non-Kaposi sarcoma vascular tumors (12 hemangiomas and one epithelioid hemangioendothelioma) and 24 cases of Kaposi sarcoma, all from known HIV-positive patients, were immunostained for LANA and evaluated for the presence of HHV-8 DNA by real-time PCR. LANA expression was seen in 22 of 24 (92%) of Kaposi sarcoma cases and in 0 of 13 non-Kaposi sarcoma cases. Real-time PCR detected HHV-8 in all of the Kaposi sarcoma cases and in four of the non-Kaposi sarcoma cases (all hemangiomas). LANA expression appears to be a highly sensitive and specific marker of Kaposi sarcoma in both the general population and in HIV-positive patients. This is in contrast to HHV-8 PCR, which is positive in a small subset of non-Kaposi sarcoma vascular tumors, most likely due to detection of HHV-8 within intratumoral blood mononuclear cells by the highly sensitive real-time PCR technique. For this reason, LANA immunohistochemistry is preferable to HHV-8 PCR for the evaluation of problematic vascular proliferations in HIV-positive individuals.

Furunculosis due to Mycobacterium mageritense associated with footbaths at a nail salon.

We report two cases of lower-extremity furunculosis caused by Mycobacterium mageritense. Both patients were patrons of the same nail salon, where they received footbaths prior to pedicures. M. mageritense bacteria isolated from two whirlpool footbaths were determined to be closely related to the patient isolates by pulsed-field gel electrophoresis.

Strong HER-2/neu protein overexpression by immunohistochemistry often does not predict oncogene amplification by fluorescence in situ hybridization.

Breast cancer patients with HER-2/neu oncogene amplification by fluorescence in situ hybridization (FISH) have been shown to have a better response to trastuzumab (Herceptin) therapy than those showing HER-2/neu protein overexpression only. Many centers currently perform FISH only on tumors showing 2+ HER-2/neu positivity by immunohistochemistry (IHC), with the assumption that 3+ positivity virtually equates with amplification. Results of FISH performed on 102 breast cancer cases over a 12-month period were correlated with HER-2/neu IHC results. FISH was performed using a ratio of HER-2/neu and chromosome 17 centromere signal counts (PathVysion; Vysis, Downers Grove, IL). Immunohistochemical expression of HER-2/neu was evaluated according to the published scoring guidelines of the HercepTest (Dako, Carpinteria, CA). Only 22 of 45 tumors with 3+ positivity (49%) showed amplification by FISH. Only 2 of 25 cases with 2+ staining by IHC (6%) showed gene amplification, and 1 of 25 cases with negative IHC staining (4%) showed weak amplification. Of the 25 cases showing oncogene amplification, 22 (88%) showed 3+ IHC positivity, 2 (8%) showed 2+ positivity, and 1 (4%) was negative by IHC. More than 50% of breast tumors showing strong 3+ HER-2/neu staining do not show oncogene amplification by FISH. Most tumors with 2+ and negative IHC also fail to amplify. In our experience, FISH studies should be performed on all 3+ and 2+ staining tumors to avoid inappropriate and toxic treatment. The decision to perform FISH on IHC-negative tumors should be guided by additional parameters, including tumor grade and estrogen receptor status.

Metastatic renal cell carcinoma to the ovary: a case report and discussion of differential diagnoses.

The clinical presentation of renal cell carcinoma in the ovary is rare and may closely resemble that of other ovarian clear cell tumors. Metastatic renal cell carcinoma was diagnosed in a patient who presented with a right adnexal mass and no other significant past medical history. The gross appearance of the tumor suggested a primary ovarian neoplasm. However, microscopic and immunohistochemical analysis revealed involvement of both ovaries by a clear cell tumor with features of renal cell carcinoma. A renal mass was subsequently discovered. We discuss the clinical, histologic, and immunohistochemical features of this tumor and the features of other clear cell neoplasms in the differential diagnosis.

Gastric endocrine pancreatic heterotopia.

Heterotopic pancreas is a relatively infrequent lesion most often found in the stomach. Four histologic types are recognized: total, canalicular, exocrine, and endocrine heterotopia. To our knowledge, only 2 cases of purely endocrine heterotopic pancreas have been reported in detail. We describe the case of a patient with gastric and duodenal ulcers and gastric endocrine heterotopia. The lack of mass formation, histomorphology, and immunohistochemical features simulating islets of Langerhans supported the diagnosis. We conclude that purely endocrine heterotopic pancreas is a very rare entity that, when present, can simulate a primary or metastatic neuroendocrine tumor. Adequate sampling of the specimen, histomorphologic pattern, and immunohistochemistry are important for the purpose of distinguishing between a neuroendocrine tumor and purely endocrine pancreatic heterotopia.