Eosinophilic Dermatosis of Hematologic Malignancy.

Eosinophilic dermatosis of hematologic malignancy (EDHM) is a rare chronic skin condition commonly affecting individuals with underlying hematologic malignancies, most notably chronic lymphocytic leukemia (CLL). EDHM presents as pruritic, insect-like bites, but without patient-reported contact/bites of insects. We present a case of a 44-year-old male who presented to Elkhorn Dermatology with a scaly rash and serpiginous borders on the nasal tip and right cutaneous upper lip. The patient was diagnosed with CLL one year prior and had been on zanubrutinib for 10 days since presenting to the dermatology clinic. Initial treatment with antifungal and antibiotic therapies showed no improvement, leading to a punch biopsy that revealed perivascular and periadnexal lymphocytic dermatitis with eosinophils. This finding, along with the patient's underlying CLL, led to a diagnosis of EDHM. This case highlights the diagnostic challenges and therapeutic complexities associated with EDHM in patients with hematologic malignancies.

IL-23 Inhibits Melanoma Development by Augmenting DNA Repair and Modulating T Cell Subpopulations.

In animal models, IL-12 and IL-23 participate in the development of malignant neoplasms of keratinocytes. However, the role of these cytokines in pigmented lesion development and their progression to melanoma has received little attention. IL-12p35, IL-23p19, and IL-12/IL-23p40 knockout mice on a C3H/HeN background, subjected to a melanomagenesis protocol, demonstrated profound differences in susceptibility to nevus initiation, transformation, tumorigenicity, and metastatic potential. IL-23 was found to be essential for melanocyte homeostasis, whereas IL-12 supported nevus development. A direct action of IL-23 on primary melanocytes, shown to be IL-23R+, demonstrated that DNA repair of damaged melanocytes requires IL-23. Furthermore, IL-23 modulated the cutaneous microenvironment by limiting regulatory T cells and IFN-γ and inhibiting IL-10 production. Neutralizing Ab to IFN-γ, but not IL-17, inhibited nevus development (p < 0.01).

CD123 immunohistochemistry for plasmacytoid dendritic cells is useful in the diagnosis of scarring alopecia.

BACKGROUND: Distinguishing types of lymphocytic scarring alopecia is often difficult because of the overlapping features. Recently, the presence of plasmacytoid dendritic cells (PDCs) in cutaneous lupus erythematosus (LE) was demonstrated and further shown to help distinguish lupus from other dermatoses.1-6 This study aims to determine if the presence and distribution of PDCs can aid in the diagnosis of scarring alopecia. METHODS: Cases of scarring alopecia due to chronic cutaneous lupus erythematosus (CCLE), lichen planopilaris (LPP) and central centrifugal cicatricial alopecia (CCCA) were examined histopathologically. A total of 45 total biopsies were evaluated and CD123 immunohistochemistry was performed on all samples. The relative percentage of PDCs, the presence of clusters and the distribution of CD123+ cells were noted. RESULTS: PDCs comprised a greater percentage of the infiltrate and were arranged in clusters in cases of CCLE vs. LPP or CCCA. In CCLE, the location of PDCs was perivascular, perifollicular, perieccrine and/or at the follicular junction. In LPP and CCCA, PDCs were mainly arranged as single, interstitial cells. CONCLUSIONS: Our findings suggest that the presence and arrangement of CD123+ PDCs may assist in the diagnosis of scarring alopecia. We anticipate this will be of value in diagnosing challenging cases of highly inflammatory scarring alopecia.

A murine model for the development of melanocytic nevi and their progression to melanoma.

Acquired melanocytic nevi are commonly found in sun exposed and unexposed human skin, but the potential for their transformation into invasive melanoma is not clear. Therefore, a mouse model of nevus initiation and progression was developed in C3H/HeN mice using a modified chemical carcinogenesis protocol. Nevi develop due to DNA damage initiated by dimethylbenz(a) anthracene (DMBA) followed by chronic promotion with 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Dysplastic pigmented skin lesions appeared in 7-9 wk with 100% penetrance. Nests of melanocytic cells appeared in a subset of skin draining lymph nodes (dLN) by 25 wk, but not in age matched controls. Immunohistochemistry, real-time PCR, and flow cytometric analyses confirmed their melanocytic origin. Transformed cells were present in a subset of nevi and dLNs, which exhibited anchorage-independent growth, tumor development, and metastasis in nude mice. Approximately 50% of the cell lines contained H-Ras mutations and lost tumor suppressor p16(Ink4a) expression. While most studies of melanoma focus on tumor progression in transgenic mouse models where the mutations are present from birth, our model permits investigation of acquired mutations at the earliest stages of nevus initiation and promotion of nevus cell transformation. This robust nevus/melanoma model may prove useful for identifying genetic loci associated with nevus formation, novel oncogenic pathways, tumor targets for immune-prevention, screening therapeutics, and elucidating mechanisms of immune surveillance and immune evasion.

A Histological Snapshot of Hypothetical Multistep Progression From Nevus Sebaceus to Invasive Syringocystadenocarcinoma Papilliferum.

Syringocystadenocarcinoma papilliferum (SCACP) is an extremely rare adnexal neoplasm, believed to arise in a preexisting nevus sebaceus of Jadassohn (NSJ) through a multistep progression process. This hypothetical process involves an NSJ giving rise to syringocystadenoma papilliferum, which then presumably undergoes malignant transformation in rare circumstances to give rise to SCACP in situ, which finally progresses to an invasive SCACP. Of the 30 SCACP cases reported so far, none have documented the process from a birthmark to the final invasive lesion, with histological evidence of each step, in a single tumor. Here, the authors report just such a case. A 74-year-old man presented with a recently enlarging birthmark on the scalp. Excisional biopsy showed an invasive SCACP, in the background of SCACP in situ, syringocystadenoma papilliferum, and NSJ. Furthermore, this tumor showed a concurrent pigmented trichoblastoma and histological evidence of lymphovascular invasion, events that have not been documented with SCACP. Interestingly, all these component lesions were present on a single histological section of this solitary tumor. Regional lymph node metastasis, a rare occurrence in SCACP, was also present in this remarkable case. The authors discuss the implications of these findings in light of the review of relevant literature.

Dermatological clues to the diagnosis of atypical complete DiGeorge syndrome.

Atypical complete DiGeorge syndrome (DGS) is an extremely rare congenital disease characterized by an eczematous dermatitis, lymphadenopathy, and an oligoclonal T-cell proliferation. Because its initial presentation may be confused with other types of eczematous dermatitis, diagnosis and treatment are usually delayed. We describe herein a case of an infant with atypical complete DGS to draw attention to the clinical and histopathological findings that lead us to the diagnosis.

Primary Cutaneous T-cell Lymphoma With Coexpression of T-Cell Receptors αß and γδ.

T lymphocytes belong to 2 distinct sublineages that express either αß or γδ T-cell receptor (TCR) complex. Although malignancy is a great instigator of lineage infidelity, as exemplified by aberrant expression of numerous lineage markers in lymphoma cells, malignant T cells rarely coexpress αß and γδ TCR complexes. Similarly, only rare cases of CD4/CD8 double-positive primary cutaneous T-cell lymphoma have been reported. In this report, we describe a remarkable case of primary cutaneous T-cell lymphoma coexpressing αß and γδ TCR complexes, strong diffuse CD8, and a very restricted coexpression of CD4 and CD8. A 66-year-old man was referred to our center for treatment of a persistent eczematoid eruption of 6 years of duration. An initial biopsy demonstrated not only marked spongiosis, but also an epidermotropic population of CD4 small mature T cells with partial expression of CD8. The process remained indolent for another year, followed by an abrupt progression with development of plaques and tumors. Repeat biopsies of these lesions demonstrated a superimposed population of large anaplastic T cells extensively involving the dermis and epidermis. The large cells showed a strong uniform expression of CD3, CD8, CD45RA, CD5, granzyme, TIA1, perforin, TCR-ß, and TCR-γ and a weaker but unambiguous expression of CD4, CD25, CD2, and CD56. TCR gene rearrangement studies showed clonal rearrangements for TCR-ß and TCR-γ with identical peaks to those seen in the biopsy from a year earlier. The patient developed lymphadenopathy, with a biopsy showing nodal involvement by a morphologically and phenotypically identical neoplastic T-cell population. The disease showed partial response to systemic chemotherapy with development of new plaques, but these new lesions have regressed with radiation therapy.

Leishmaniasis Panamensis Masquerading as Myiasis and Sporotrichosis: A Clinical Pitfall.

We report a case of cutaneous leishmaniasis panamensis in nonendemic Costa Rica. A 19-year-old female presented with nonhealing, unilateral eruption of erythematous papules with superficial central ulceration in a sporotrichoid pattern on right upper arm and back. Given the clinical picture and geographic locale, the patient was initially diagnosed with myiasis or human botfly infestation; however, the sporotrichoid pattern of the bites is an unlikely finding in myiasis. Peripheral blood smear, Giemsa stain, and polymerase chain reaction (PCR) were consistent for Leishmania spp. Ulceration resolved with 20-day course of IV sodium stibogluconate.

Shh and p50/Bcl3 signaling crosstalk drives pathogenesis of BCCs in Gorlin syndrome.

Nevoid basal cell carcinoma syndrome (NBCCS) is a rare autosomal dominant disorder that is due, in large measure, to aberrant Shh signaling driven by mutations in the tumor suppressor gene Ptch1. Here, we describe the development of Ptch1+/-/ SKH-1 mice as a novel model of this disease. These animals manifest many features of NBCCS, including developmental anomalies and are remarkably sensitive to both ultraviolet (UVB) and ionizing radiation that drive the development of multiple BCCs. Just as in patients with NBCCS, Ptch1+/-/SKH-1 also spontaneously develops BCCs and other neoplasms such as rhabdomyomas/rhabdomyosarcomas. Administration of smoothened inhibitors (vismodegib/itraconazole/cyclopamine) or non-steroidal anti-inflammatory drug (sulindac/sulfasalazine) each result in partial resolution of BCCs in these animals. However, combined administration of these agents inhibits the growth of UVB-induced BCCs by >90%. Employing small molecule- and decoy-peptide-based approaches we further affirm that complete remission of BCCs could only be achieved by combined inhibition of p50-NFκB/Bcl3 and Shh signaling. We posit that Ptch1+/-/SKH-1 mice are a novel and relevant animal model for NBCCS. Understanding mechanisms that govern genetic predisposition to BCCs should facilitate our ability to identify and treat NBCCS gene carriers, including those at risk for sporadic BCCs while accelerating development of novel therapeutic modalities for these patients.

An Idiopathic Leukonychia Totalis and Leukonychia Partialis Case Report and Review of the Literature.

Leukonychia totalis and leukonychia partialis are rare nail findings characterized by complete or partial whitening of the nail plate. Leukonychia totalis and leukonychia partialis are usually inherited or associated with systemic disease. Here, we report the case of a 25-year-old man with idiopathic acquired leukonychia totalis and leukonychia partialis and review the literature on this topic.

Epidermolysis bullosa nevus in a patient with recessive dystrophic epidermolysis bullosa: a case report.

We present a case of a 6-year-old girl with recessive dystrophic epidermolysis bullosa (EB) who presented with a large pigmented lesion clinically concerning for melanoma. After histological examination and fluorescent in situ hybridization analysis, diagnosis of EB nevus was performed. EB nevi are benign melanocytic neoplasms with histological findings similar to recurrent nevi occurring in all types of EB. They often mimic melanoma clinically, dermatoscopically, and histopathologically. The ability to recognize an EB nevus is essential for appropriate management of the patient. Unnecessary surgical excision in patients with already high-risk EB should be avoided. Close monitoring of these lesions is recommended because no cases of transformation to melanoma have been described.

Paraneoplastic pityriasis rubra pilaris as the presenting manifestation of metastatic squamous cell carcinoma.

Pityriasis rubra pilaris (PRP) is a rare idiopathic papulosquamous eruption. Few cases of PRP have been reported in association with malignancies. We report a case of an 83-year-old Caucasian male who presented with recalcitrant paraneoplastic PRP as the presenting manifestation of metastatic squamous cell carcinoma with unknown primary. Treatment with chemotherapy and radiation led to temporary radiologic and symptomatic regression of the cancer as well as resolution of cutaneous findings. This suggests a direct relationship between the PRP and the underlying malignancy in this patient. This case highlights a rare, but important phenomenon in which PRP may act as a harbinger for underlying malignancy.

Transepithelial elimination in sarcoidosis: a frequent finding.

BACKGROUND: Transepithelial elimination is a process by which dermal materials are expelled through an active epithelial-dermal connective tissue interaction. It has been described as a regular or sporadic occurrence in a variety of dermatologic conditions, including sarcoidosis. OBSERVATION: Our patient demonstrated a rare presentation of sarcoidosis involving the genital region, with histopathologic evidence of transepithelial elimination of granulomas. This prompted us to conduct the first case series documenting the frequency of transepithelial elimination in sarcoidosis. METHODS: Slides of skin biopsies from patients (n = 50) with cutaneous sarcoidosis from the University of Alabama at Birmingham were evaluated for transepithelial elimination. Transepithelial elimination was defined as epithelial channel formation with a sarcoidal-type granuloma completely surrounded by squamous epithelium on the section examined. RESULTS: Transepithelial elimination was found in 9 of 50 cases (18%). CONCLUSION: This is the first report of transepithelial elimination in a lesion of sarcoidosis localized to the vulvar area, and one of only six reports in the English literature documenting cutaneous sarcoidosis with histopathologic evidence of transepithelial elimination. These reports are reviewed herein. Surprisingly, the results from this case series indicate that transepithelial elimination is more common in cutaneous sarcoidosis than one may surmise from the current literature.