Psoriatic alopecia - fact or fiction? A clinicohistopathologic reappraisal.

BACKGROUND: The incidence of psoriatic alopecia in psoriatic patients is underwhelming, given the prevalence of psoriasis in the North American population. Recently, a 60-year-old Albanian female, lacking a significant medical history for psoriasis, presented to our clinic with a 1-year history of "dandruff" associated with itch, hair thinning, and histopathologic evidence consistent with prior reports of "psoriatic alopecia." AIMS: The absence of preceding or concomitant psoriasis suggests that the patient's alopecia is an antecedent manifestation of psoriasis, thus prompting this retrospective study to ascertain better the relationship between alopecia and psoriasis. METHODS: We performed a retrospective review of 33 scalp biopsies on 31 patients having histopathologic diagnosis of psoriasis belonging to 31 patients seen between 2007 and 2010. RESULTS: Alopecia was a presenting feature in 48% of cases with definitive clinical and/or histopathologic diagnosis of psoriasis (scale crust with neutrophils, psoriasiform epidermal hyperplasia, and hypogranulosis). The most common follicular-related changes were infundibular dilatation (87%) followed by perifollicular fibrosis (77%), perifollicular lymphocytic inflammation (68%), thinning of the follicular infundibulum (55%), and fibrous tracts (28%). Of interest, sebaceous glands were absent in 60% and atrophic in 25% of cases. CONCLUSION: While a major limitation of this study is that it is a retrospective one, given that these changes are common to varying degrees in all lymphocytic scarring alopecias, we posit that psoriatic alopecia likely represents a secondary clinical change to a primary process and is not a unique histopathologic entity. A prospective study with a control group that includes lymphocytic scarring alopecias from non-psoriatic patients is required to support our findings.

Levamisole-induced vasculopathy: a report of 2 cases and a novel histopathologic finding.

Although cocaine-induced pseudovasculitis and urticarial vasculitis have been reported in the past, levamisole-induced vasculopathy with ecchymosis and necrosis, termed here LIVEN, has only recently been described in association with cocaine use. Levamisole, a veterinary antihelminthic agent used previously as an immunomodulating agent, is present as a "cutting agent" in approximately two-thirds of the cocaine currently entering the United States. Levamisole is believed to potentiate the effects of cocaine and may also be used as a "signature" for tracing its market distribution. Herein, we report 2 cases of LIVEN in patients with histories of chronic cocaine use. In both the cases, a temporal association with neutropenia preceding the eruption was noted. A novel histopathologic finding present only in the second case was the presence of extensive interstitial and perivascular neovascularization. Our 2 cases reaffirm that neutropenia may precede the cutaneous eruption of LIVEN. Case 2 extends the spectrum of histopathologic findings to include the novel phenomenon of neovascularization-hitherto unreported in this entity.

Adenomatous eccrine metaplasia--a novel reaction pattern.

We recently observed atypical adenomatous metaplasia of eccrine glands in an excisional biopsy of squamous cell carcinoma (SCC). This led us to this study in an effort to ascertain whether this reaction pattern is common to all excisional biopsies and, depending on its presence in association with residual tumor, whether it is lineage specific. We performed a retrospective review of 201 excisional biopsies and noted that adenomatous metaplasia was present in 35 of 201 (17%) of the cases, of which 19 had residual tumor. Adenomatous metaplasia seemed to be more frequent in epithelial neoplasms such as basal cell carcinomas 15 of 94 (16%) and SCCs 13 of 61 (21%) although only (3 of 41) 7% of nevomelanocytic proliferations exhibited this change. Residual tumor was noted in association with adenomatous metaplasia, in 11 of 15 cases (73%) in the basal cell carcinoma subgroup, in 8 of 13 cases (62%) in the SCC subgroup, and in none from the nevomelanocytic subgroup. Comparing frequencies of adenomatous metaplasia across groups, only SCC specimens with residual tumor demonstrated a statistically significant increase compared with nevomelanocytic neoplasm (35% vs. 7%, P = 0.01). Findings from the current study expand the spectrum of metaplastic change involving eccrine glands to include adenomatous metaplasia. Given that it seems to be more common to epithelial malignancies, it seems reasonable to posit that this reaction pattern is the consequence of hitherto undefined proteins induced by epithelial tumor cells resulting in exuberant stimulation of eccrine glands, although immunohistochemical and molecular studies are required to define the precise cause.

Nests with numerous SOX10 and MiTF-positive cells in lichenoid inflammation: pseudomelanocytic nests or authentic melanocytic proliferation?

Pseudomelanocytic nests in the setting of lichenoid inflammation can mimic atypical melanocytic proliferations. Both melanocytic and cytokeratin immunohistochemical stains may be utilized to differentiate these entities. Unlike true melanocytic nests, pseudomelanocytic nests contain Melanoma Antigen Recognized by T-cells 1 (MART-1)/ Melan-A-positive cells and cells positive for pan-cytokeratins, CD3 and/or CD68. Recently, rare (1-2 cells/nest) microphthalmia- associated transcription factor (MiTF)-positive cells were also reported in pseudomelanocytic nests. We present a 48-year-old man with a 2 × 3 cm violaceous to hyperpigmented, non-blanching, polygonal patch on the neck. Histopathology showed focal epidermal atrophy, irregularly distributed junctional nests and a lichenoid infiltrate with colloid bodies. Immunoperoxidase studies revealed occasional pan-cytokeratin and MART-1/Melan-A-positive staining in nests as well as focal S-100 protein-positive cells. Importantly, the majority of nests showed numerous cells positive for MiTF and SOX10 (>2 cells/nest and some the majority of cells). This combined staining pattern confounds the above-described immunohistochemical distinction between pseudo and true melanocytic nests. Clinically felt to represent unilateral lichen planus pigmentosus/erythema dyschromicum perstans and not malignant melanoma in situ, this lesion highlights the importance of clinicopathologic correlation and suggests either a new melanocytic entity or a novel pattern of benign melanocytic reorganization in a subset of lichenoid dermatitides.