Acute Interstitial Inflammation on Skin Biopsies and Positive Tissue Cultures in Cellulitis Patients Are Associated a Worse Prognosis.

Background: Cellulitis is a significant public health burden and lacks a gold standard for diagnosis. Up to 1/3 of patients are incorrectly diagnosed. The skin biopsy has been proposed as the gold standard.

A rare tonsillar metastasis of Merkel cell carcinoma: A case report.

Merkel cell carcinoma (MCC) metastasis to the tonsil is extremely rare with five published cases. We report the case of a patient with palatine tonsillar MCC metastasis, who presented without oropharyngeal symptoms, which contrast prior reported cases.

Talimogene laherparepvec pseudolymphomatous reaction mimicking metastatic melanoma.

Talimogene laherparepvec (TVEC) is a genetically modified herpes simplex virus-1 approved as an intralesional oncolytic immunotherapy for the treatment of advanced melanoma. Cutaneous reactions at the site of injection may mimic recurrent or progressive melanoma; histopathological findings have included chronic granulomatous dermatitis, neutrophilic dermatitis, lymphocytic dermatitis, and pigment incontinence. We report a 39-year-old male with metastatic stage IIIc melanoma treated with TVEC with clinical regression of melanoma lesions that later developed pink nodules at sites of prior injection.

GATA-3 expression in a de-differentiated chondrosarcoma with cutaneous iatrogenic implantation: a diagnostic pitfall with important clinical implications.

De-differentiated chondrosarcoma (DDCS) is an extremely aggressive tumor of the bone characterized by a high-grade, non-chondroid sarcoma adjacent to a low- or intermediate-grade chondrosarcoma. Adequate tumor sampling demonstrating the biphasic features is necessary to make an accurate diagnosis. The diagnosis may be challenging as histopathology may mimic other neoplasms.

Atypical Cellular Blue Nevus With Necrosis Mimicking Melanoma Ex-Blue Nevus.

Histologic distinction between melanoma ex-blue nevus and cellular blue nevus (CBN) can often be difficult, but features supporting melanoma include infiltrative growth pattern, frequent mitoses, cytologic atypia and pleomorphism, cell crowding, and tumor necrosis. Unfortunately, these features are not constantly dependable and frequently borderline lesions exist, so-called atypical CBN, which lack explicit malignant features. Furthermore, some CBN and atypical CBN show an assortment of features, which may lead to their misdiagnosis as melanoma, but to date necrosis is generally absent.

Peristomal Punctate Pemphigus.

Cutaneous reactions surrounding abdominal stoma sites are typically irritant, allergic, infectious, traumatic or pathergic in etiology. Pemphigus, which encompasses a group of vesiculobullous autoimmune skin disorders, is seldom encountered as a peristomal dermatosis. Direct immunofluorescence (DIF) studies of pemphigus generally show continuous intercellular net-like depositions of IgG.

Acquired Epidermodysplasia Verruciformis in the Setting of Renal Transplant.

Epidermodysplasia verruciformis (EV) is a rare dermatologic condition that is clinically characterized by flat, cutaneous, verrucous papules, pityriasis versicolor-like lesions, and similar lichenoid papules. There are 2 forms of EV: a classic inherited genodermatosis and a secondary acquired form. EV predisposes individuals to infections with certain types of human papillomavirus virus and subsequently increases the risk of cutaneous squamous cell carcinoma.

An Unusual Presentation of Pyemotes ventricosus Dermatitis Presenting With Umbilicated Papules Mimicking Poxvirus Infection.

Pyemotes ventricosus mites are an uncommon cause of pruritic dermatitis seen most commonly in occupational exposure, prominently found in professionals such as farmers, landscapers, and factory workers who work with grains, wheat, dried beans, or grasses. The clinical description of the rash has typically been described as papular, erythematous, with a central vesicular lesion. We describe a case of Pyemotes dermatitis with an atypical clinical presentation.