A Rare Case of Ectopic Hidradenoma Papilliferum of the External Auditory Canal.

Hidradenoma papilliferum (HP) is a benign adnexal tumor, commonly affecting the anogenital region of middle-aged women. Clinically, HP typically presents as a slow-growing, unilateral, well-circumscribed, smooth skin-colored cystic dermal nodule, usually growing less than 1 cm in size. Reports of ectopic HP are exceedingly rare but have been identified in areas containing modified apocrine gland structures, most commonly on the head and neck, and have included ceruminous glands of the external ear canal, the Moll glands of the eyelid, mammary glands of the breast, maxillofacial region and areas on the scalp. To the best of our knowledge, there is only one case of ectopic HP located on the external ear canal reported in English literature. We present a second case of draining ectopic HP located on the conchal bowl of the external ear canal.

Downregulation of Caveolae-Associated Proteins in Psoriasis: A Case Series Study.

We have previously identified that a structural membrane protein Caveolin-1 (Cav1) is involved in the regulation of aberrant keratinocyte proliferation and differentiation. The aim of this study was to elucidate the role of Cav1, Caveolin-2 (Cav2), and Cavin-1 in the pathogenesis of psoriasis vulgaris and between psoriasis subtypes. We utilized human biopsies from validated cases of psoriasis vulgaris (n = 21) at the University of Miami Hospital and compared the expression of Cav1, Cav2, and Cavin-1 by immunohistochemistry staining with that in normal healthy age-/sex-/location-matched skin (n = 15) and chronic spongiotic dermatitis skin samples (as control inflammatory skin condition) and quantified using QuPath. Distinct subtypes of psoriasis included guttate, inverse, nail, plaque, palmoplantar, and pustular. All biopsy samples exhibited a trend toward downregulation of Cav1, with nail, plaque, and palmoplantar psoriasis exhibiting the most pronounced effects. Only nail and pustular psoriasis samples exhibited significant downregulation of Cav2 and Cavin-1, suggesting Cav1 to be the main caveolar contributor to the pathogenesis of psoriasis. Together, these data support caveolae as pathophysiological targets in nail and pustular psoriasis, whereas Cav1 seems to be a general biomarker of multiple subtypes of psoriasis.

IL-17 Expression in the Perifollicular Fibrosis in Biopsies From Lichen Planopilaris.

BACKGROUND: Lichen planopilaris (LPP) is a primary lymphocytic cicatricial alopecia for which therapy is often ineffective and there is no cure. OBJECTIVES: Looking for a new targetable molecule in the treatment of LPP, we sought to verify whether IL-17 expression is increased in scalp biopsies from patients with active scalp lesions of LPP. METHODS: Horizontal sections of hematoxylin and eosin-stained slides from 40 scalp biopsies of active LPP were retrospectively collected and stained with the monoclonal antibody against IL-17 (Abcam, Cambridge, MA; ab79056, dilution 1:100). Twenty biopsies from patients with chronic telogen effluvium served as controls because of their morphological resemblance to the normal scalp. Statistical analysis was performed using IBM SPSS Statistics for Windows (IBM Corporation, Armonk, NY). RESULTS: The main finding was the positive cytoplasmic expression of IL-17 in the perifollicular fibrosis of the affected follicles in LPP which was statistically significant compared with the controls ( P < 0.0001). The labeled cells were identified as fibroblasts based on their spindle shape and fascicular concentric arrangement in tight perifollicular distribution. Although most of the LPP specimens (n = 35; 87.5%) also revealed cytoplasmic IL-17 expression in the lichenoid inflammatory infiltrate, the results were not statistically significant ( P = 0.1351). CONCLUSION: Our immunohistochemistry results show that blocking the IL-17 inflammatory pathway may interfere with the progression of the perifollicular fibrosis and inflammation in LPP.

Papuloerythroderma of Ofuji.

Papuloerythroderma of Ofuji (PEO) is a rare skin condition first described in 1984 and characterized by diffuse erythroderma composed of papules coalescing into plaques with sparing of skin folds, known as the deck-chair sign. The disease is almost exclusively seen in the elderly and affects men more frequently than women. Common laboratory findings include peripheral and tissue eosinophilia, elevated levels of immunoglobulin E, and lymphopenia. The diagnosis entails exclusion of potentially causative pathologies, including drug intake, atopy, malignancy, and infection. These factors have frequently been found in association with PEO, but their role in the etiopathogenesis of the disease is poorly understood. A dysregulated immune system, with particular involvement of T-helper (Th)2 and Th22 cells, seems to be important in the development of PEO. Controversy exists as to whether PEO exists as an independent entity or as a clinical pattern of a variety of distinct conditions. Treatment necessitates first addressing any coexisting circumstances that may have a causal relationship with PEO. In idiopathic cases, topical and oral corticosteroids, ultraviolet light therapies, and immunosuppressive/immunomodulating therapies have been used with variable results. Future studies are needed to further understand the disease process and to establish guidelines for diagnostic workup and treatment.

Cutaneous Presentation of T-Cell Prolymphocytic Leukemia Mimicking Dermatomyositis.

ABSTRACT: T-cell prolymphocytic leukemia (TPLL) is a rare form of leukemia by T lymphocytes at a post-thymic intermediate stage of development with an α/ß immunophenotype. Facial involvement is common in TPLL and displays significant heterogeneity of the lesions' description and location. TPLL also contains a wide array of histology findings, cell cytology, and molecular studies. Here, we describe a TPLL patient who presented with an ill-defined erythematous patch involving the right axilla progressing to the left axilla, upper back, and face that resembled dermatomyositis. The diagnosis of TPLL was established using flow cytometry of bone marrow and peripheral blood, and histopathology of the involved skin. Dermatologists should be aware of these unique features.

Development of Chancre-Variant Cutaneous Tuberculosis After BCG Vaccine Administration in a Patient With Migraines.

In countries other than the United States, the BCG vaccine is typically used as a method for preventing childhood tuberculosis; in the United States, the BCG vaccine has gained popularity as a speculated therapy for autoimmune and inflammatory disorders. Research suggests that the vaccine can train the innate immune response, thereby improving symptoms of disorders such as diabetes and fibromyalgia. However, the potential side effects associated with the use of this vaccine are not totally innocuous. Although 95% of recipients should expect common skin complications after administration of the BCG vaccine, other more serious cutaneous sequelae may occur. Potential cutaneous side effects associated with vaccine use can include fistulation, abscess formation, and even ulceration. This brief report highlights a patient in whom cutaneous tuberculosis developed, specifically tuberculous chancre, secondary to receiving the BCG vaccine as a possible treatment for fibromyalgia. After undergoing surgical debulking of the tumor, the patient subsequently received the standard of care to the wound base and was started on 6 months of isoniazid monotherapy. Cutaneous tuberculosis is exceedingly rare, and the chancre variant accounts for only about 1% of diagnosed cases. Although common in pediatric populations, the chancre variant of cutaneous tuberculosis is not typically seen in adult populations, most likely because the BCG vaccine is often administered to children to prevent childhood tuberculosis. As use of the BCG vaccine in adults becomes more prevalent to potentially treat or mitigate certain disorders, it is imperative that health care providers recognize the potentially severe side effects associated with its use.

Lichenoid drug eruption after treatment with ixekizumab for plaque psoriasis.

Lichen Planus (LP), the prototype of lichenoid dermatoses, is an idiopathic, T cell-mediated, autoimmune, inflammatory disease. It may affect the skin, hair, nails, and mucous membranes. Many clinical variants of LP have been described, including lichenoid drug eruption or drug induced LP, associated with a myriad of culprit medications. We describe a 63-year-old woman with longstanding psoriasis effectively controlled with ixekizumab, who developed lichenoid drug eruption . Her lichen planus lesions improved after treatment discontinuation and the patient was started on an IL23 inhibitor to treat her psoriasis through an alternative mechanism of action. Our report adds to the literature and provides insight into the complex pathophysiology of lichen planus.

Muir-Torre Syndrome.

A 64-year-old man was referred to our dermatology clinic with a diagnosis of Muir-Torre syndrome (MTS), he had a history of multiple sebaceous carcinomas and sebaceous adenomas removed over the years. The patient has also had visceral cancer and had undergone a colon resection 17 years before to treat colon cancer and was recently diagnosed with invasive high-grade urothelial carcinoma of the right ureter. In addition, the patient has an extensive family history of cancer; a pedigree was constructed to document this history (Figure 1). Of note is that the patient's mother and father were second cousins. The patient's father was diagnosed with lung cancer at age 57 and died of colon cancer at the age of 72. The patient's mother died of colon cancer at age 74. The patient has three siblings: a sister and two brothers. The sister died of bone cancer at age 42. One brother had a number of cancers including colon, kidney, and skin cancers and died at age 53. His other brother is alive and has a history of colon cancer, kidney cancer, and ureteral cancer. The patient has five children. He has a 40-year-old son who, at the age of 30, was diagnosed with testicular cancer. His daughters are 47, 44, 39, and 34, with no history of malignancy to date. The patient had three maternal aunts, all of whom succumbed to colon cancer, as well as two paternal uncles who died of lung cancer. The patient's maternal grandfather was a smoker and he also died of lung cancer.

Multidrug resistant gastrointestinal stromal tumor with multiple metastases to the skin and subcutaneous soft tissue: A case report and review of literature.

Gastrointestinal stromal tumors (GISTs) are mesenchymal neoplasms which account for less than 1% of all gastrointestinal malignancies. Of all the extra-abdominal metastases of GIST, superficial soft tissue metastases are the rarest. Previous reports have found success with sunitinib in imatinib-resistant GIST, but we report a certain wild-type KIT mutation GIST with cutaneous and subcutaneous metastasis that was unresponsive to multiple tyrosine kinase inhibitor (TKI) treatments. This case illustrates that knowing the specific type of KIT mutations may uncover resistance of certain GIST's to TKIs, necessitating more targeted and alternative therapy.

Carcinosarcoma of the hand.

Carcinosarcomas are rare malignant tumors derived of both epithelial and mesenchymal elements. Herein, we report an elderly man originally diagnosed with a squamous cell carcinoma of the hand. Upon excision, the tumor was found to be a more aggressive carcinosarcoma. Immunohistochemical stains revealed that the sarcoma component of the lesion was vimentin positive, whereas the primary carcinoma tumor cells were positive for p63 and CK903. Both components were negative for CD34 and D2-40. This tumor was found to have angiolymphatic invasion and eventually metastasized to the axillary lymph nodes and lungs.

Clear Cell Acanthoma on the Areola.

Clear cell acanthoma (CCA) is a rare, benign cutaneous condition most often seen on the lower extremities. Lesions are of variable morphology and have been described as polypoid, pigmented, giant, and cystic lesions. Although no racial or gender predilection has been reported, CCA on the breast is a very rare finding that has been observed mainly in young Korean women. Herein, we describe a case of CCA of the areola in an elderly woman with metastatic renal cell carcinoma. Physical exam revealed a pink plaque with central erosions on the left areola. Given the concern for cutaneous metastasis, excisional biopsy was performed, which showed pale glycogenated epithelium consistent with CCA. No evidence of recurrence or new lesions was observed after 6 months of follow-up. Our case exemplifies that clinicians should consider CCA in the differential diagnosis for a new eczematous lesion involving the breast, even in the setting of malignancy.

KSHV-induced ligand mediated activation of PDGF receptor-alpha drives Kaposi's sarcomagenesis.

Kaposi's sarcoma (KS) herpesvirus (KSHV) causes KS, an angiogenic AIDS-associated spindle-cell neoplasm, by activating host oncogenic signaling cascades through autocrine and paracrine mechanisms. Tyrosine kinase receptor (RTK) proteomic arrays, identified PDGF receptor-alpha (PDGFRA) as the predominantly-activated RTK in KSHV-induced mouse KS-tumors. We show that: 1) KSHV lytic replication and the vGPCR can activate PDGFRA through upregulation of its ligands PDGFA/B, which increase c-myc, VEGF and KSHV gene expression in infected cells 2) KSHV infected spindle cells of most AIDS-KS lesions display robust phospho-PDGFRA staining 3) blocking PDGFRA-signaling with N-acetyl-cysteine, RTK-inhibitors Imatinib and Sunitinib, or dominant-negative PDGFRA inhibits tumorigenesis 4) PDGFRA D842V activating-mutation confers resistance to Imatinib in mouse-KS tumorigenesis. Our data show that KSHV usurps sarcomagenic PDGFRA signaling to drive KS. This and the fact that PDGFRA drives non-viral sarcomas highlights the importance for KSHV-induced ligand-mediated activation of PDGFRA in KS sarcomagenesis and shows that this oncogenic axis could be successfully blocked to impede KS tumor growth.

Scanning the Immunopathogenesis of Psoriasis.

Psoriasis is a chronic inflammatory skin disease, the immunologic model of which has been profoundly revised following recent advances in the understanding of its pathophysiology. In the current model, a crosstalk between keratinocytes, neutrophils, mast cells, T cells, and dendritic cells is thought to create inflammatory and pro-proliferative circuits mediated by chemokines and cytokines. Various triggers, including recently identified autoantigens, Toll-like receptor agonists, chemerin, and thymic stromal lymphopoietin may activate the pathogenic cascade resulting in enhanced production of pro-inflammatory and proliferation-inducing mediators such as interleukin (IL)-17, tumor necrosis factor (TNF)-α, IL-23, IL-22, interferon (IFN)-α, and IFN-γ by immune cells. Among these key cytokines lie therapeutic targets for currently approved antipsoriatic therapies. This review aims to provide a comprehensive overview on the immune-mediated mechanisms characterizing the current pathogenic model of psoriasis.

A Case of Circumscribed Scalp Morphea with Perineural Lymphocytes on Pathology.

Scalp morphea presents as a scarring alopecia in en coup du sabre pattern. We report an unusual presentation of a round hairless patch of morphea on the occipital scalp present for 15 years. The scalp lesion aligned with 2 other hyperpigmented lesions of biopsy-proven morphea in the lower back. Pathology of horizontal sections from the scalp lesion showed follicular dropout, thickening of the collagen bundles, and preserved eccrine and follicular structures. Marked lymphocytic perineural infiltrate, a reported clue to the diagnosis of scalp morphea, contributed to the diagnosis. This case is unusual due to its rare clinical presentation. It also highlights the importance of recognizing histopathological clues for the diagnosis of uncommon scalp disorders.