Approach to Neuropathic Pain.

Neuropathic pain is a common chief complaint encountered by neurologists and primary care providers. It is caused by disorders involving the somatosensory nervous system. The clinical evaluation of neuropathic pain is challenging and requires a multifaceted systematic approach with an emphasis on a thorough history and physical examination to identify characteristic signs and symptoms. Ancillary laboratory investigations, targeted imaging, and electrodiagnostic studies further help identify underlying etiologies to guide specific treatments. Management of neuropathic pain encompasses treating the underlying pathology as well as symptomatic control with nonpharmacological, pharmacological, and interventional therapies. Here, we present an approach to help evaluate patients with neuropathic pain.

Acquired Epidermodysplasia Verruciformis in the Setting of Renal Transplant.

ABSTRACT: Epidermodysplasia verruciformis (EV) is a rare dermatologic condition that is clinically characterized by flat, cutaneous, verrucous papules, pityriasis versicolor-like lesions, and similar lichenoid papules. There are 2 forms of EV: a classic inherited genodermatosis and a secondary acquired form. EV predisposes individuals to infections with certain types of human papillomavirus virus and subsequently increases the risk of cutaneous squamous cell carcinoma. The acquired form occurs in immunosuppressed patients, particularly in patients infected with HIV; however, it has also been described in patients who have undergone stem cell and solid organ transplantation. We report an additional case of renal transplantation and immunosuppressive therapy-associated acquired EV (AEV) in a 78-year-old man with multiple flesh-colored to violaceous, flat-topped papules distributed on the face and trunk clinically mimicking lichen planus. Biopsy was typical for that of EV, demonstrating enlarged keratinocytes with a blue-gray cytoplasm, a thickened granular layer, acanthosis, and hyperkeratosis. Herein, we discuss an unusual presentation of an AEV-mimicking lichen planus with review of the literature.

Atypical Cellular Blue Nevus With Necrosis Mimicking Melanoma Ex-Blue Nevus.

ABSTRACT: Histologic distinction between melanoma ex-blue nevus and cellular blue nevus (CBN) can often be difficult, but features supporting melanoma include infiltrative growth pattern, frequent mitoses, cytologic atypia and pleomorphism, cell crowding, and tumor necrosis. Unfortunately, these features are not constantly dependable and frequently borderline lesions exist, so-called atypical CBN, which lack explicit malignant features. Furthermore, some CBN and atypical CBN show an assortment of features, which may lead to their misdiagnosis as melanoma, but to date necrosis is generally absent. We present an unusual case of an atypical cellular blue nevus with extensive necrosis mimicking melanoma ex-blue nevus.

Successful treatment of bullous pemphigoid with dupilumab: a case and brief review of the literature.

Bullous pemphigoid is an autoimmune skin disease that results in formation of pruritic blisters. Most cases are treated with a combination of systemic and topical corticosteroids as well as other immunomodulatory drugs. Dupilumab is a fully human monoclonal antibody that acts as an antagonist against IL4Ra traditionally used in the treatment of atopic dermatitis. We present an 80-year-old man with moderate to severe bullous pemphigoid successfully treated with dupilumab.

An Unusual Presentation of Pyemotes ventricosus Dermatitis Presenting With Umbilicated Papules Mimicking Poxvirus Infection.

Pyemotes ventricosus mites are an uncommon cause of pruritic dermatitis seen most commonly in occupational exposure, prominently found in professionals such as farmers, landscapers, and factory workers who work with grains, wheat, dried beans, or grasses. The clinical description of the rash has typically been described as papular, erythematous, with a central vesicular lesion. We describe a case of Pyemotes dermatitis with an atypical clinical presentation. A 30-year-old man presented with pruritic, umbilicated papules, which involved his right lateral trunk and upper thigh leading to the submitted clinical impression of molloscum contagiosum. A biopsy of the skin was taken, and fragments of arthropod consistent with P. ventricosus were identified within umbilicated indentations of skin. The patient subsequently admitted to the onset of the rash immediately after carrying bales of straw while supporting each bale with his right side. The possibility of Pyemotes dermatitis mimicking a poxvirus-like eruption should be considered when encountering an unusual umbilicated papular eruption in the appropriate patient with occupational exposure.

The utility of using immunohistochemistry in the differentiation of metastatic, cutaneous clear cell renal cell carcinoma and clear cell hidradenoma.

BACKGROUND: Clear cell hidradenoma and cutaneous clear cell renal cell carcinoma (CCRCC) overlap morphologically. The distinction may be difficult in a patient with a history of CCRCC, presenting with a cutaneous nodule, potentially leading to an erroneous diagnosis. We investigated the usefulness of napsin A and paired box gene 8 (PAX-8) with previously studied markers epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), vimentin and cluster of differentiation marker 10 (CD10) in differentiating CCRCC from hidradenoma. METHODS: We evaluated hidradenomas and cutaneous CCRCCs for immunohistochemical expression of napsin A, PAX-8, EMA, CEA, vimentin and CD10. RESULTS: PAX-8 was expressed in all CCRCCs (8/8) while negative in hidradenomas. Napsin A was negative in both hidradenomas (0/12) and CCRCCs (0/10). EMA showed membranous reactivity in 11 of 12 hidradenomas and 8 of 10 CCRCCs; and highlighted ductal epithelium in 1 of 12 hidradenomas and cystic areas in 4 of 10 CCRCCs. CD10 showed ductal expression in 3 of 12 hidradenomas and membranous staining in 8 of 9 CCRCCs. CEA highlighted ductal epithelium in 11 of 12 hidradenomas while absent in CCRCCs (0/10). Vimentin highlighted neoplastic cells in 8 of 8 CCRCCs and failed to stain the hidradenomas (0/12). CONCLUSION: A conservative immunohistochemical panel including PAX-8, vimentin and CEA allow for easy distinction of CCRCC from hidradenoma, whereas napsin A added no additional value.

Fibroblastic connective tissue nevus.

Fibroblastic connective tissue nevus (FCTN) is a newly recognized, benign cutaneous mesenchymal lesion of fibroblasts/myofibroblastic lineage, which expands the classification of connective tissue nevi. We present three cases of FCTN and discuss significant clinical, morphologic and immunophenotypic overlap with dermatomyofibroma. Our cases were from young women, aged 32, 24 and 10, and presented as 1.2 and 1 cm nodules on the posterior neck and right upper flank, respectively while presenting as a linear plaque of the right posterior thigh in the latter case. The lesions showed a poorly circumscribed proliferation of hypercellular spindle cells arranged in short to longer intersecting fascicles entrapping adnexal structures. Superficial adipose tissue was also entrapped in one case. The spindle cells had fibroblastic features with pale eosinophilic cytoplasmic extensions and inconspicuous nucleoli. The spindle cells were positive for CD34 in two cases. One case was negative for CD34, smooth muscle actin (SMA), desmin and S100. The overall features were consistent with a diagnosis of FCTN. In two cases, we further elucidated the fibroblastic differentiation of the spindle cells in FCTN with electron microscopy, which has not been previously described.

Can MDM2 analytical tests performed on core needle biopsy be relied upon to diagnose well-differentiated liposarcoma?

Well-differentiated liposarcoma/atypical lipomatous tumor can be difficult to differentiate from benign lipomatous tumors, especially on limited biopsy material. Adjunctive tests for MDM2 (murine double minute 2) have proven useful in whole-tissue sections; however, their utility has not been determined within the increasingly popular core needle biopsy. Herein, we compare the ability of MDM2 immunohistochemistry and MDM2 fluorescence in situ hybridization (FISH) to discriminate benign lipomatous tumors from well-differentiated liposarcoma on core needle biopsies. Well-differentiated liposarcoma (n=17) and an assortment of benign lipomatous tumors (n=37), which had concurrent or previous core needle biopsies, and resection specimens were subjected to both MDM2 immunohistochemistry and MDM2 FISH on both whole-tissue sections and corresponding core needle biopsy sections. Percentage tumor cells positive for MDM2 by immunohistochemistry and an MDM2:CEP12 FISH ratio was calculated in each biopsy and resection specimen pair and the results were compared. MDM2 FISH had a higher sensitivity (100%) and specificity (100%) compared with MDM2 immunohistochemistry (65 and 89%) in core needle biopsies, respectively. In addition, MDM2 immunohistochemistry had a false-positive rate of 11%, compared to 0% with FISH. The average MDM2:CEP12 ratio was similar in the biopsy material compared with the whole-tissue sections in both well-differentiated liposarcoma and the benign lipomatous tumor group of neoplasms. Detection of MDM2 amplification by FISH is a more sensitive and specific adjunctive test than MDM2 immunohistochemistry to differentiate well-differentiated liposarcoma from various benign lipomatous tumors, especially on limited tissue samples.

Synthesis of monodisperse [Oct4N(+)][Au25(SR)18(-)] nanoparticles, with some mechanistic observations.

A single phase (THF) synthesis of monodisperse [Oct(4)N(+)][Au(25)(SR)(18)(-)] nanoparticles is described that yields insights into pathways by which it is formed from initially produced larger nanoparticles. Including the Oct(4)N(+)Br(-) salt in a reported single phase synthetic procedure enables production of reduced nanoparticles having a fully occupied HOMO molecular energy level (Au(25)(SR)(18)(-), as opposed to a partially oxidized state, Au(25)(SR)(18)(0)). The revised synthesis accommodates several (but not all) different thiolate ligands. The importance of acidity, bromide, and dioxygen on Au(25) formation was also assessed. The presence of excess acid in the reaction mixture steers the reaction toward making Au(25)(SR)(18); while bromide does not seem to affect Au(25) formation, but it may play a role in maintaining the -1 oxidation state. Conducting the nanoparticle synthesis and "aging" period in the absence of dioxygen (under Ar) does not produce small nanoparticles, providing insights into the pathway of reaction product "aging" in the synthesis solvent, THF. The "aging" process favors the Au(25)(-) moiety as an end point and possibly involves degradation of larger nanoparticles by hydroperoxides formed from THF and oxygen.

Non-mycosis fungoides cutaneous T-cell lymphoma: reclassification according to the WHO-EORTC classification.

BACKGROUND: Non-mycosis fungoides (non-MF) primary cutaneous T-cell lymphomas (PCTCL) are heterogeneous and divided into subgroups by the World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification of cutaneous lymphomas. We report the first North American series to examine the applicability of the classification, compare our findings with the predominant European literature and confirm the significance of separation into the indolent and aggressive groups. METHODS: Forty-four non-MF PCTCL cases with available tissue for phenotyping, adequate clinical staging information and follow-up were reclassified according to the WHO-EORTC classification. RESULTS: Non-MF PCTCL had a longer overall survival (OS) (13.8 years) compared with secondary cutaneous T-cell lymphoma (SC-TCL) (2.5 years). Primary cutaneous anaplastic large cell lymphoma (PC-ALCL) had the most favorable outcome (OS 14.1 years), whereas secondary and primary peripheral T-cell lymphoma, unspecified had the shortest OS (2.5 and 2.4 years, respectively). Primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma (CTLCD4) appeared to have a favorable course. CONCLUSIONS: Most non-MF PCTCL can be classified according to the WHO-EORTC classification. The relative frequencies are similar to European experience. Non-MF PCTCL is a heterogeneous group with a favorable outcome compared to SC-TCL, especially PC-ALCL and CTLCD4. Separation of non-MF PCTCL into indolent and aggressive groups appears clinically significant and may provide direction for therapeutic decisions.

Quantitative analysis of eosinophils in acute graft-versus-host disease compared with drug hypersensitivity reactions.

Acute graft-versus-host disease (aGVHD), if not detected and treated early, is a common cause of morbidity and mortality. Drug hypersensitivity reactions (DHRs), the most frequent clinical and histopathological mimickers of early aGVHD, are often still distinguished from aGVHD by the presence of eosinophils within the inflammatory infiltrate on skin biopsy. Distinguishing these entities is important because the delay of appropriate treatment of aGVHD may lead to advanced stages of the disease process with a poor prognosis. To determine whether the existence or amount of eosinophilic infiltrate could be used to differentiate these entities, we employed a quantitative method of analyzing eosinophils in skin biopsies of rashes from patients with aGVHD and DHR. Eosinophils were counted in 50 high-power fields (HPFs) in skin biopsies of patients with clinical grade >or=2 aGVHD (+aGVHD), with clinical grade <2 aGVHD (-aGVHD), and those with clinical DHR (+DHR). The average number of eosinophils per 10 HPFs (ave. eos/10 HPFs) increased throughout each group. The ave. eos/10 HPFs in +DHR was significantly different from both aGVHD groups (P < 0.001). The specificity to completely rule out aGVHD did not reach 100% until 16.0 ave. eos/10 HPFs was observed. There is a significant difference between the numbers of eosinophils found in differentiating DHR from aGVHD, but a very high number (>16.0 ave. eos/10 HPFs) is necessary to rule out aGVHD completely. Therefore, a quantitative analysis of eosinophils in all biopsies to rule out aGVHD would be of limited value and should only be considered in those biopsies with significant eosinophilia.

Detection of MDM2 gene amplification or protein expression distinguishes sclerosing mesenteritis and retroperitoneal fibrosis from inflammatory well-differentiated liposarcoma.

Inflammatory liposarcoma is a variant of well-differentiated liposarcoma/atypical lipomatous tumor that consists of a mixture of lymphocytes, histiocytes, scattered atypical stromal cells, mature adipocytes, and rarely lipoblasts. When the inflammatory infiltrate predominates, the morphological features overlap with various fibroinflammatory disorders including sclerosing mesenteritis and retroperitoneal fibrosis, making the diagnosis difficult. Well-differentiated liposarcoma/atypical lipomatous tumor and dedifferentiated liposarcoma have characteristic molecular markers in the form of giant marker and ring chromosomes consisting of amplicons of 12q13-15, which includes MDM2. MDM2 immunohistochemistry (IHC) (Zymed; clone IF2) and dual color fluorescence in situ hybridization utilizing MDM2 (12q15) and chromosome 12 centromeric probes were performed on formalin-fixed and paraffin-embedded specimens from inflammatory well-differentiated liposarcoma (17 cases), sclerosing mesenteritis (14 cases), and idiopathic retroperitoneal fibrosis (10 cases). MDM2 expression as detected by IHC is a very sensitive tool in recognizing inflammatory well-differentiated liposarcoma (17 of 17); however, 21% (3 of 14) and 10% (1 of 10) of sclerosing mesenteritis and retroperitoneal fibrosis, respectively, displayed weak MDM2 immunoexpression. The MDM2 fluorescence in situ hybridization assay was very specific for inflammatory well-differentiated liposarcoma as 15 of 17 (88%) cases showed MDM2 amplification, whereas none of the cases of sclerosing mesenteritis or idiopathic retroperitoneal fibrosis showed amplification. Five cases of retroperitoneal fibrosis were noncontributory secondary to autofluorescence, potentially limiting the usefulness of the assay in certain situations such as inappropriate fixation. Increased MDM2 expression and/or MDM2 amplification can be employed to aid discrimination of inflammatory well-differentiated liposarcoma from fibroinflammatory mimics. MDM2 fluorescence in situ hybridization is a very specific method (100%), but less sensitive (88%), whereas MDM2 expression by IHC is very sensitive (100%), but less specific (83%). Therefore, a positive screen of difficult cases with MDM2 IHC would require confirmation by the fluorescence in situ hybridization. However, lack of MDM2 immunoexpression would rule out the possibility of inflammatory well-differentiated liposarcoma.

Initial presentation of stasis dermatitis mimicking solitary lesions: a previously unrecognized clinical scenario.

BACKGROUND: Stasis dermatitis is a common skin condition secondary to chronic venous insufficiency. Characteristic dermatologic changes in well-developed disease include bilateral erythematous, scaly, and slightly discolored papules and plaques on the lower legs. Earlier signs, such as prominent superficial veins and pitting ankle edema, are well known. Early recognition of signs and appropriate diagnosis can lead to timely treatment that can prevent painful complications, such as leg ulcers which are at risk for development of squamous cell carcinoma. OBJECTIVE: Herein we describe a yet unrecognized early sign of venous dermatitis-a solitary lesion, some mimicking neoplastic processes. METHODS: Thirty-seven cases of stasis dermatitis submitted with the clinical diagnosis of a solitary lesion were identified. Thirty-three had no clinical history of venous insufficiency. All cases of stasis dermatitis presenting for the first time as a solitary lesion were reviewed retrospectively both clinically and pathologically. RESULTS: Squamous cell carcinoma was most commonly suspected (33%), followed by basal cell carcinoma (24%), and a variety of other solitary lesions. The histopathology was characteristic of stasis dermatitis in all cases with absent or mild spongiosis (82%), variable acanthosis and dermal fibrosis, and proliferation of papillary dermal thick-walled vessels were prominent (2-3+) in nearly all cases (>or=90%) along with hemosiderin-laden macrophages and extravasated red blood cells (>or=95%). LIMITATIONS: The study is limited by its retrospective nature and absence of clinical images on all cases. CONCLUSION: Stasis dermatitis may present as a solitary lesion mimicking a neoplasm. Early recognition of stasis dermatitis can lead to appropriate treatment and possibly prevent further morbidity.

Simple non-staining method to demonstrate urate crystals in formalin-fixed, paraffin-embedded skin biopsies.

BACKGROUND: Gouty tophi classically occur as nodules over joints and the helix. The ideal fixative for preservation of gout crystals has traditionally been alcohol because the crystals are formalin and water soluble. However, most biopsies are submitted in formalin fixative, which results in dissolution of urate crystals leaving behind a non-specific pale amorphous area. Although complex staining methods to show urate crystals in tissue have been described, the present study elucidates a simple non-staining method utilizing a thick unstained coverslipped microscopy slide that allows detection and confirmation of birefringence of urate crystals in formalin-fixed, paraffin-embedded tissue. METHODS: Twenty-nine cases of cutaneous gouty tophi were evaluated using a hematoxylin-eosin (H&E)-stained section, a 10-microm unstained coverslipped section and a 4-microm unstained coverslipped section. In all cases, the specimen was received and submitted in formalin. RESULTS: Polarizable crystals were not identified in any of the H&E sections. The use of the thicker unstained coverslipped section was more sensitive than the standard 4 microm section by recognizing the characteristic urate crystals in 48% and 38% of the cases, respectively. CONCLUSIONS: This inexpensive adjunctive tool can be used to document gout crystals in almost half of skin biopsies.

Postradiation cutaneous vascular tumors of the breast: a review.

Postradiation vascular tumors fall into two categories: (1) postradiation cutaneous angiosarcoma, malignant vascular neoplasms with significant morbidity and mortality; and (2) atypical vascular lesions (AVL), vascular tumors that reportedly behave in a benign manner. Postradiation vascular tumors not only present a therapeutic problem for clinicians, but they present an increasingly common diagnostic dilemma for pathologists. Although first described separately 15 years ago, the relationship between postradiation cutaneous angiosarcoma and AVL remains controversial. It appears that, in at least some cases, angiosarcoma can arise in the context of AVL, suggesting that these lesions are part of a spectrum of the same disease process. This latter view point is supported by the significant clinical and histologic overlap found between both tumors. Herein, we will discuss the evolution of this topic while reviewing the various clinical, histopathologic, and prognostic characteristics of postradiation cutaneous angiosarcoma and AVL.

Current state of educational compensation in academic neurology: Results of a US national survey.

In the current medical climate, medical education is at risk of being de-emphasized, leading to less financial support and compensation for faculty. A rise in compensation plans that reward clinical or research productivity fails to incentivize and threatens to erode the educational missions of our academic institutions. Aligning compensation with the all-encompassing mission of academic centers can lead to increased faculty well-being, clinical productivity, and scholarship. An anonymous survey developed by members of the A.B. Baker Section on Neurologic Education was sent to the 133 chairs of neurology to assess the type of compensation faculty receive for teaching efforts. Seventy responses were received, with 59 being from chairs. Key results include the following: 36% of departments offered direct compensation; 36% did not; residency program directors received the most salary support at 36.5% full-time equivalent; and administrative roles had greatest weight in determining academic compensation. We believe a more effective, transparent system of recording and rewarding faculty for their educational efforts would encourage faculty to teach, streamline promotions for clinical educators, and strengthen undergraduate and graduate education in neurology.

Fluorescence in situ hybridization for MDM2 gene amplification as a diagnostic tool in lipomatous neoplasms.

Well-differentiated liposarcoma/atypical lipomatous tumor and dedifferentiated liposarcoma can be difficult to distinguish from benign lipomatous neoplasms and other high-grade sarcomas, respectively. Cytogenetics in these tumors has identified ring and giant chromosomes composed of 12q13-15 amplicons including the MDM2 gene. Identifying MDM2 amplification by fluorescence in situ hybridization may prove an adjunctive tool in the diagnosis of lipomatous neoplasms. Dual color fluorescence in situ hybridization employing a laboratory-developed BAC label probe cocktail specific for MDM2 (12q15) and a probe for the centromeric region of chromosome 12 (Abbott Molecular, DesPlaines, IL) was performed on formalin-fixed and paraffin-embedded tissue including whole sections from atypical lipomatous tumors (n=13), dedifferentiated liposarcomas (n=14), benign lipomatous tumors (n=30), and pleomorphic sarcoma, not otherwise specified (n=10), and a tissue microarray containing a variety of high-grade sarcomas (n=63). An MDM2/chromosome 12 ratio >or=2.0 was considered amplified, <2.0 nonamplified, and cases displaying >2 signals of both probes and an MDM2 ratio <2.0 polysomic for chromosome 12. Of the well-differentiated and dedifferentiated liposarcomas, 100% showed amplification of MDM2. Chromosome 12 polysomy was noted in 89% of spindle cell/pleomorphic lipomas, while all angiolipomas and lipomas were nonamplified and eusomic. MDM2 amplification was observed in 40% of pleomorphic sarcomas and a small subset of high-grade sarcomas (3/63). MDM2/chromosome 12 fluorescence in situ hybridization is a sensitive and specific tool (both 100%) in evaluating low-grade lipomatous neoplasms. The specificity decreases in high-grade sarcomas, as MDM2 amplification was observed in a small portion of pleomorphic sarcomas and high-grade sarcomas other than dedifferentiated liposarcomas. Importantly, none of the benign lipomatous lesions were MDM2 amplified and even cells in areas of well-differentiated liposarcomas with minimal cytologic atypia were amplified, making the probe a valuable tool in the diagnosis of even limited biopsy samples of well-differentiated lipomatous neoplasms.