An unusual case of multiple grouped non-familial trichoepitheliomas.

Trichoepitheliomas (TEs) are benign and rare adnexal hamartomas of the pilosebaceous units. Trichoepitheliomas could occur in the setting of an underlying genetic disorder with multiple TEs or as solitary non-hereditary TEs. We report a healthy 32-year-old woman with sporadic multiple clustered and non-segmental TEs without positive family history. There have been two other cases reported in the literature that had non-familial multiple TEs, one was facially disfiguring and the other was in a segmental pattern. Our case has been the only one reported in the English literature which has sporadic, multiple TEs clustered unilaterally and non-segmentally on the trunk.

Subcorneal pustular dermatosis associated with IgG monoclonal gammopathy of undetermined significance.

Subcorneal pustular dermatosis is a rare chronic relapsing bullous neutrophilic dermatosis. Because it can be associated with monoclonal gammopathy of undetermined significance and multiple myeloma, screening for these conditions is necessary. Herein, we present a case of subcorneal pustular dermatosis, with concurrent monoclonal gammopathy of undetermined significance, successfully treated with acitretin.

Generalized fixed drug eruption to piperacillin/tazobactam and review of literature.

Fixed drug eruption (FDE) is an adverse drug reaction characterized by the development of well-circumscribed, round, dusky erythematous macules and plaques on cutaneous or mucosal surfaces. The reaction occurs on the same mucosal or cutaneous site with subsequent exposures to the offending drug. Although FDE usually manifests as a single lesion, in rare instances, more than one lesion may arise and this is referred to as a generalized eruption. Herein, we present a 31year-old man with history of cystic fibrosis who developed a generalized fixed drug eruption to piperacillin/tazobactam (Zosyn, Pfizer). We discuss our patient's course and review causes and outcomes of generalized fixed drug eruptions in the literature.

Improving classification of melanocytic nevi: Association of BRAF V600E expression with distinct histomorphologic features.

BACKGROUND: A subset of melanomas carrying a B-Raf proto-oncogene, serine/threonine kinase gene (BRAF) V600E mutation, which is the most common targetable mutation in melanoma, arise in association with a melanocytic nevus that is also harboring a BRAF V600E mutation. The detailed histomorphologic characteristics of nevi positive for BRAF V600E have not been systematically documented. OBJECTIVE: To identify histomorphologic features correlating with BRAF V600E status in nevi. METHODS: We retrospectively identified melanocytic nevi from our laboratory reporting system. We performed a histomorphologic analysis and analysis of BRAF V600E expression by immunohistochemistry. RESULTS: Thirteen nevi (14.8%) were negative and 76 (86.4%) were positive for BRAF V600E. The nevi positive for BRAF V600E were predominantly dermal (predominantly dermal growth in 55.3% of nevi positive for BRAF V600E and 15.4% of nevi negative for BRAF V600E [P = .01]) and showed a congenital growth pattern (congenital growth pattern in 51.3% of nevi positive for BRAF V600E and 15.4% of nevi negative for BRAF V600E [P = .02]). Compared with nevi negative for BRAF V600E, those that were positive for BRAF V600E often exhibited predominantly nested intraepidermal melanocytes, larger junctional nests, abrupt lateral circumscription, and larger cell size. Architectural disorder and inflammatory infiltrates were seen more often in nevi negative for BRAF V600E. BRAF sequencing of a subset of nevi confirmed the immunohistochemical results. LIMITATIONS: Limitations include the study's retrospective design and the small sample size of nevi negative for BRAF V600E. CONCLUSIONS: BRAF V600E is associated with distinct histomorphologic features in nevi. These features may contribute to improving the accuracy of classification and diagnosis of melanocytic neoplasms.

Desmoplastic intradermal spitz nevi arising within red tattoo ink.

Tattoos present a diagnostic challenge for dermatologists. Various reactions to tattoo have been identified in the literature ranging from allergic, to infectious, to neoplastic. Of the neoplastic cases identified, it is unclear whether the tattoo ink was directly causative, or if the cases were merely coincidence, as the number of cutaneous malignancies has also been on the rise. We present a novel case of two desmoplastic intradermal Spitz nevi arising within red tattoo ink.

Psoriasis or not? Review of 51 clinically confirmed cases reveals an expanded histopathologic spectrum of psoriasis.

BACKGROUND: Psoriasis is usually diagnosed clinically, so only non-classic or refractory cases tend to be biopsied. Diagnostic uncertainty persists when dermatopathologists encounter features regarded as non-classic for psoriasis. OBJECTIVE: Define and document classic and non-classic histologic features in skin biopsies from patients with clinically confirmed psoriasis. METHODS: Minimal clinical diagnostic criteria were informally validated and applied to a consecutive series of biopsies histologically consistent with psoriasis. Clinical confirmation required 2 of the following criteria: (1) classic morphology, (2) classic distribution, (3) nail pitting, and (4) family history, with #1 and/or #2 as 1 criterion in every case RESULTS: Fifty-one biopsies from 46 patients were examined. Classic features of psoriasis included hypogranulosis (96%), club-shaped rete ridges (96%), dermal papilla capillary ectasia (90%), Munro microabscess (78%), suprapapillary plate thinning (63%), spongiform pustules (53%), and regular acanthosis (14%). Non-classic features included irregular acanthosis (84%), junctional vacuolar alteration (76%), spongiosis (76%), dermal neutrophils (69%), necrotic keratinocytes (67%), hypergranulosis (65%), neutrophilic spongiosis (61%), dermal eosinophils (49%), compact orthokeratosis (37%), papillary dermal fibrosis (35%), lichenoid infiltrate (25%), plasma cells (16%), and eosinophilic spongiosis (8%). CONCLUSIONS: Psoriasis exhibits a broader histopathologic spectrum. The presence of some non-classic features does not necessarily exclude the possibility of psoriasis.

Malignancy-associated Sweet syndrome: acute febrile neutrophilic dermatosis associated with recurrence of metastatic cervical cancer.

We present a rare case of acute febrile neutrophilic dermatosis, also known as Sweet syndrome, associated with recurrence of metastatic cervical cancer. This report highlights similar reports and serves as an important reminder of the relationship between Sweet syndrome and cervical cancer. Increasing awareness of Sweet syndrome assists clinicians in recognizing characteristic findings and encourages evaluation of patients for new-onset or recurrent neoplastic disease. Additionally, we discuss the typical presentation of the syndrome, the proper workup and treatment, and a common pitfall encountered in the diagnosis of Sweet syndrome.

Severe pellagra masked by concurrent plaque psoriasis: a case report of a hidden diagnosis.

Despite characteristic features, psoriasis can mimic other dermatologic conditions, such as seborrheic dermatitis, lichen simplex chronicus, and certain nutritional deficiencies such as pellagra. We present a patient with a longstanding history of severe plaque psoriasis who presented with disfiguring scaly plaques involving greater than 80% body surface area. The patient's disease was minimally responsive to multiple therapies. Repeat punch biopsies demonstrated parakeratosis, psoriasiform hyperplasia, and dilated blood vessels consistent with psoriasis. Given atypical clinical features and overall poor treatment response additional work up was obtained. A serum nutritional panel was consistent with niacin deficiency and the patient later revealed extensive alcohol intake. A diagnosis of concurrent pellagra was made and the patient was started on niacin supplementation and instructed to reduce alcohol intake, while continuing adalimumab and high potency topical steroids. Within two weeks, his disease had markedly improved. Pellagra presents characteristically with a photosensitivity dermatitis that may appear clinically and histologically similar to psoriasis. It is important to maintain an index of suspicion for a secondary pathology in treatment-resistant psoriasis.

Acantholytic squamous cell carcinoma is usually associated with hair follicles, not acantholytic actinic keratosis, and is not "high risk": Diagnosis, management, and clinical outcomes in a series of 115 cases.

BACKGROUND: Acantholytic squamous cell carcinoma (aSCC) is regarded as a high-risk variant of cutaneous squamous cell carcinoma (SCC). Acantholytic actinic keratosis (aAK) has been regarded as a precursor risk factor for aSCC. However, supporting evidence is limited. OBJECTIVE: We sought to document clinical features, histologic features, management, and outcomes in a series of aSCC cases. METHODS: Definitions of aSCC, aAK, and aSCC arising in association with aAK were applied to a consecutive series of aSCC cases. Clinical characteristics and outcomes were obtained from electronic medical records. RESULTS: Of 115 aSCC cases (103 patients, mean age 71.8 years), actinic keratosis was present in 23% (27/115) but only 7.8% (9/115) exhibited associated aAK. Ten cases (10/115, 9%) fulfilled strict histologic criteria for follicular SCC as previously defined, but 50 of 115 (43%) of our aSCC cases exhibited predominant involvement of follicular epithelium rather than epidermis. Clinical outcome (median follow-up, 36 months) was available in 106 of 115 (92%). One patient experienced regional extension (parotid), and 1 patient experienced a local recurrence (nose). No disease-related metastases or deaths were documented. LIMITATIONS: This was a single-institution retrospective study from the United States. CONCLUSIONS: The presence of acantholysis in cutaneous SCC does not specifically confer aggressive behavior, a finding that may inform clinical practice guidelines.

Classic Ulcerative Pyoderma Gangrenosum Is a T Cell-Mediated Disease Targeting Follicular Adnexal Structures: A Hypothesis Based on Molecular and Clinicopathologic Studies.

BACKGROUND: Pyoderma gangrenosum (PG) is a debilitating ulcerative skin disease that is one of the most common associated diseases seen in patients with inflammatory bowel disease and rheumatoid arthritis. Although PG is classified as a neutrophilic dermatosis, its pathophysiology is poorly understood. OBJECTIVE: Use data obtained from patient-reported histories, immunohistochemistry, and gene expression analysis to formulate a hypothesis on PG pathophysiology. METHODS: Ten PG patients participated and answered questions about new ulcer formation. Skin biopsies of healed prior ulcers and adjacent normal skin were obtained from four patients for immunohistochemistry. Scars from healthy patients and patients with discoid lupus were used as additional controls. New onset PG papules were analyzed using immunohistochemistry and gene expression analysis via quantitative real-time PCR. RESULTS: All PG patients reported that healed sites of previous ulceration are refractory to re-ulceration. Simultaneous biopsies of healed and uninvolved skin triggered ulceration only in the latter. On immunohistochemistry, healed PG scars showed complete loss of pilosebaceous units, which were present in normal skin, and to a lesser extent in control scars, and discoid scars. Early PG papules showed perivascular and peripilosebaceous T cell infiltrates, rather than neutrophils. These early inflammatory events were dominated by increased gene expression of CXCL9, CXCL10, CXCL11, IL-8, IL-17, IFNG, and IL-36G and transcription factors consistent with Th1 phenotype. LIMITATIONS: Small sample size was the main limitation. CONCLUSION: We put forth the hypothesis that PG is a T cell response resulting in the destruction of pilosebaceous units.