Neutrophilic dermatosis after azathioprine exposure.

IMPORTANCE: Azathioprine hypersensitivity syndrome can present clinically and histopathologically like Sweet syndrome. Shared clinical features include fever, constitutional symptoms, prompt response to systemic corticosteroid therapy, neutrophilia, and abrupt onset of erythematous cutaneous lesions. Histologically, both azathioprine hypersensitivity syndrome and Sweet syndrome are rich in neutrophils. OBSERVATIONS: An 81-year-old woman with Crohn disease presented with fever and an acute eruption of plaques on her extremities within 2 weeks of starting treatment with azathioprine. Laboratory evaluation was notable for leukocytosis and neutrophilia. Skin biopsy of an erythematous plaque on the thigh demonstrated a suppurative folliculitis. Azathioprine treatment was discontinued resulting in resolution of the clinical lesions within 5 days. Our case was compared with 18 cases with similar clinical features. CONCLUSIONS AND RELEVANCE: We report a case of azathioprine hypersensitivity syndrome and review the literature on azathioprine-induced eruptions with features of Sweet syndrome. Our patient's distribution of lesions on the extremities and the finding of suppurative folliculitis on histopathology were not classical for Sweet syndrome. Azathioprine hypersensitivity syndrome seems to be a neutrophil-driven dermatosis; therefore, many overlapping features with Sweet syndrome are not surprising. Due to the potential for anaphylaxis with azathioprine rechallenge, a better term for a Sweetlike presentation in the setting of azathioprine administration is azathioprine hypersensitivity syndrome.

Neuropilin-2 as a useful marker in the differentiation between Spitzoid malignant melanoma and Spitz nevus.

BACKGROUND: Spitzoid malignant melanoma (SMM) shares many histopathologic features with Spitz nevus (SN). The distinction between SMM and SN remains one of the most difficult diagnostic problems in dermatopathology. Neuropilin-2 (NRP2) is a cytoplasmic/cell surface protein that is a mediator of melanoma-endothelial cell interaction. OBJECTIVE: The aim of this study was to evaluate NRP2 expression in SMM and SN and to determine whether it can reliably differentiate between the 2 groups. METHODS: We studied the expression of NRP2 in 19 cases of SMM and 19 cases of SN from Yale Spitzoid Neoplasm Repository, New Haven, Conn. RESULTS: All 19 cases of SMM (100%) expressed NRP2. Most SMM showed moderate- and high-intensity staining in the majority of the melanoma cells. Most of the SN (14/19, 74%) were negative for the marker. NRP2 labeled only 5 of 19 SN (26%) and all of them demonstrated mild staining intensity. NRP2(+) staining was statistically significant in differentiating SMM from SN (P < .05). LIMITATIONS: Small study size is a limitation. CONCLUSIONS: NRP2 expression in SMM and SN may be a useful adjunct marker, in addition to histopathologic evaluation, in the differentiation between these 2 entities.

Perifollicular fibroma in Birt-Hogg-Dubé syndrome: an association revisited.

BACKGROUND: Mutation in the folliculin gene in Birt-Hogg-Dubé (BHD) syndrome leads to a spectrum of benign tumors of the hair follicle, classically including both fibrofolliculoma and trichodiscoma. In addition, lesions clinically indistinguishable from fibrofolliculoma/ trichodiscoma may show histopathologic findings of perifollicular fibroma or angiofibroma. Although some consider perifollicular fibroma to be a variant of angiofibroma, the specific histopathologic findings of perifollicular fibroma are uncommon. METHODS: This is a case series. RESULTS: In 4 patients with multiple facial lesions, recognizing perifollicular fibroma would have been helpful in leading to the diagnosis of BHD syndrome. CONCLUSION: Perifollicular fibroma is on a spectrum with fibrofolliculoma and trichodiscoma; in a patient with multiple lesions, the diagnosis of perifollicular fibroma is suggestive of BHD syndrome.

Light microscopic hair shaft analysis in ectodermal dysplasia syndromes.

The objective of the study was to catalog hair shaft abnormalities in individuals with ectodermal dysplasia (ED) syndromes using light microscopy and to compare findings with those in unaffected controls. Light microscopy was performed in a nonblinded manner on hair shafts from 65 participants with seven types of ED (hypohidrotic ED, ED-ectrodactyly-cleft lip or palate, ankyloblepharon-ectodermal defects-cleft lip and palate, Clouston syndrome, Goltz syndrome, Schopf-Schulz Passarge syndrome, and oculodentodigital dysplasia) and 41 unaffected controls. Hair donations were collected at the 28th Annual National Family Conference held by the National Foundation for Ectodermal Dysplasia. Control participants were recruited from a private dermatology practice and an academic children's hospital outpatient dermatology clinic. Sixty-five affected participants and 41 unaffected controls were included in the analysis. We assessed the hair shafts of ED and control participants for abnormalities visible using LM. Light microscopy identified various pathologic hair shaft abnormalities in each type of ED, although none of the findings were statistically significantly different from those of the control group. Light microscopy is a poor adjuvant tool in the diagnosis of ED syndromes. Most findings are nonspecific and not sufficiently sensitive.

Nevi of special sites.

Melanocytic nevi can have a wide range of histologic appearances. Within the spectrum of nevi, there exists a group that presents in certain anatomic locations with histologically worrisome features but nonetheless benign behavior. This group of nevi has been broadly categorized as nevi of special sites. The anatomic locations affected by this group include the embryonic milkline (breast, axillae, umbilicus, genitalia), flexural areas, acral surfaces, ear, and scalp. Nevi in these locations may be mistaken for melanomas because of their histologic appearance, resulting in inappropriate overtreatment of patients. In this article, the authors review the histologic features of these special site nevi and discuss the criteria that help distinguish them from melanoma.

Treatment of acne conglobata with modern external beam radiation.

Like other diseases of the follicular occlusion tetrad, acne conglobata can be difficult to treat. We describe the successful use of modern external beam radiation for acne conglobata in the case of a 53-year-old man with long-standing and disfiguring acne conglobata and hidradenitis suppurativa. For patients with severe acne conglobata resistant to more accepted therapies, modern external beam radiation may be a viable alternative on the therapeutic ladder.

Nevi of Special Sites.

Melanocytic nevi can have a wide range of histologic appearances. Within the spectrum of nevi, there exists a group that presents in certain anatomic locations with histologically worrisome features but nonetheless benign behavior. This group of nevi has been broadly categorized as nevi of special sites. The anatomic locations affected by this group include the embryonic milkline (breast, axillae, umbilicus, genitalia), flexural areas, acral surfaces, ear, and scalp. Nevi in these locations may be mistaken for melanomas because of their histologic appearance, resulting in inappropriate overtreatment of patients. In this article, the authors review the histologic features of these special site nevi and discuss the criteria that help distinguish them from melanoma.

Cutaneous blastomycosis: a diagnostic challenge.

Primary cutaneous inoculation blastomycosis occurs less commonly than secondary blastomycosis, in which cutaneous lesions most often originate from a primary pulmonary infection which disseminates through the blood or lymphatics to involve the skin. In secondary cutaneous blastomycosis, the primary pulmonary infection is frequently subclinical at the time cutaneous lesions manifest. Here we report two cases that illustrate the difficulty in distinguishing between primary and secondary cutaneous involvement. We also review the expanding literature on blastomycosis since its identification over a century ago.

Nevirapine-induced Stevens-Johnson syndrome in a pediatric patient.

Nevirapine is a non-nucleoside reverse transcriptase inhibitor commonly used in human immunodeficiency virus-1 multidrug regimens and associated with life-threatening cutaneous reactions. Here, we report the successful use of intravenous immunoglobulin in a pediatric patient with Stevens-Johnson syndrome and highlight the risk of nevirapine usage in human immunodeficiency virus postexposure prophylaxis.

Primary systemic amyloidosis associated with multiple myeloma: a case report and review of the literature.

Amyloidosis is a broad and complex class of diseases that comprises several etiologies, many manifestations, and a diversity of outcomes. We discuss a patient with primary systemic amyloidosis associated with multiple myeloma that illustrates many of the typical and atypical features of the disease process. Despite more in-depth assessment and accurate classification, survival for patients with primary systemic disease remains poor.