Diagnostic utility of WT-1 cytoplasmic stain in variety of vascular lesions.

Vascular lesions are commonly encountered in routine pathologic practice and often pose diagnostic challenges owing to their morphologic diversity. Although WT-1 expression was reported in some vascular tumors, little is known about its staining patterns in a spectrum of vascular lesions from various locations. We examined WT-1 immunostain in 95 cases of vascular lesions including angiosarcomas (AS, 19 cases), hemangioendotheliomas (HE, 5), Kaposi's sarcomas (KS, 4), cavernous hemangiomas (CVH, 12), capillary hemangiomas (CPH, 7), pyogenic granulomas (PG, 4), lymphangiomas (LA, 4), hemangiopericytomas (HP, 5), glomus tumors (GT, 8), vascular malformation (VM, 13) and granulation tissue (GRT, 14). Strong WT-1 cytoplasmic stain was invariably observed in all cases of malignant and borderline vascular tumors including AS (19/19), KS (4/4) and HE (5/5). WT-1 was also consistently expressed in CPH (7/7), PG (4/4), and GRT (14/14), while it became weaker in VM (10/13) and often negative in CVH (2/12) and LA (0/4). WT1 stain was not demonstrated in HP (0/5) and rarely in GT (2/8). We conclude that consistent and diffuse WT-1 cytoplasmic stain in AS, HE and KS can be useful in distinguishing these tumors from poorly differentiated tumors with mimicking features. On the other hand, reliable WT-1 stain in CPH, PG and GRT may help in differential diagnosis with non-endothelial vascular tumors such as GT and HP. Recognizing the WT-1 cytoplasmic stain in a broad spectrum of benign and neoplastic tissues is critical in formulating appropriate immunohistochemical panels and avoiding misinterpretation of results.

Verrucous herpes of the scrotum presenting clinically as verrucous squamous cell carcinoma: case report and review of the literature.

We report a case of a 36-year-old man with acquired immunodeficiency syndrome (AIDS) and an enlarging scrotal mass presumed to be of malignant origin but found to be a rare instance of verrucous herpes simplex type 2 infection of the scrotum. We also review the literature on this subject and discuss pathogenesis of the disease.

The impact of LSIL-H terminology on patient follow-up patterns: a comparison with LSIL and ASC-H.

The Papanicolaou (Pap) test category of "low grade squamous intraepithelial lesion, cannot exclude high grade squamous intraepithelial lesion" (LSIL-H) is not recognized by The Bethesda System but is commonly used. It is essentially an amalgamation of the official LSIL and ASC-H categories. Since these two categories have similar follow-up algorithms, the clinical utility of the combined LSIL-H category is unclear. We have therefore studied follow-up patterns for these three entities in our laboratory to determine the real-world impact of each in our patient population. We searched our pathology database over an 18-month period to find Pap tests (predominantly ThinPrep) interpreted as LSIL-H (137), LSIL (2,189), and ASC-H (101). Like other studies, we found that the discovery rate of high grade dysplasia in biopsies after LSIL-H (31.9%) was similar to ASC-H (35.3%) and was higher than LSIL (7.6%; P < 0.0001). In women with no previous history of dysplasia, the frequency of biopsy follow-up after the initial Pap test was significantly higher for LSIL-H (68.3%) than for LSIL (49.6%; P = 0.0038) and similar to ASC-H (62.3%). We also found that women with an initial negative biopsy or a biopsy positive for low grade dysplasia were more likely to undergo an additional biopsy if the initial Pap test was LSIL-H (36.2%) than if it was LSIL (18.2%; P = 0.0023). ASC-H (26.9%) had an intermediate rate. In our patient population, the use of the terminology LSIL-H is associated with follow-up biopsy patterns much more similar to ASC-H than to LSIL.

Cutaneous phaeohyphomycosis caused by Paraconiothyrium cyclothyrioides.

Paraconiothyrium cyclothyrioides is a recently described coelomycetous fungal species. We present a case in a renal transplant patient with chronic skin lesions of the lower extremities caused by P. cyclothyrioides. Treatment with posaconazole led to complete resolution of the lesions. P. cyclothyrioides should be considered an opportunistic human pathogen in immunocompromised patients.

Diffuse Large B-Cell Lymphoma at the Site of a Herpes Zoster Scar.

Herpes zoster, also known as shingles, occurs upon reactivation of a primary infection with varicella zoster virus (VZV). Risk factors for reactivation include stress, older age, and immunosuppression, all of which are associated with a decrease in host immunity. Common complications of herpes zoster include scarring and post-herpetic neuralgia (PHN). Cutaneous lesions such as granuloma annulare, lymphomas, and sarcoid granulomas have also been reported to potentially arise at the site of herpes zoster. Here, we report a case that to our knowledge is the first presentation of diffuse large B-cell lymphoma with its only cutaneous manifestation arising in a herpes zoster scar. Punch biopsy was performed on a nodule appearing in a dermatomal distribution within the herpes zoster scar. Histopathology revealed an atypical lymphoid infiltrate in the dermis that was determined to be CD20 positive B-cells. Immunostains for CD20, CD79a, and PAX-5 showed strong positive staining of the atypical cells, confirming B-cell origin and resulting in the diagnosis of lymphoma, large B-cell type. This case highlights the importance of raising clinical suspicion for a malignant process in patients who present with a changing or unresolving skin manifestation after infection with varicella zoster virus.