Spindle cell lipoma: a rare case report on the hallux

Spindle cell lipomas are a rare type of lipoma usually presenting in middle-aged to older men, often located on the posterior neck or shoulder; presentation on the foot is exceptionally uncommon. We report a 24-year-old man with spindle cell lipomas on the hallux of his left foot. He experienced an uneventful recovery after excision of the mass. We discuss clinical, radiologic, and histopathologic features of spindle cell lipomas and we review the differential diagnosis at this anatomic site.

Post-zoster fibroelastolytic papulosis: an example of Wolf isotopic response

Wolf isotopic response describes the onset of a new dermatosis at the site of a previous, healed dermatosis, which is usually a herpes zoster infection. Fibroelastolytic papulosis is a poorly understood elastolytic condition defined by a loss of elastic fibers specific to the papillary dermis. The present report describes a case of fibroelastolytic papulosis with onset following herpes zoster infection. This association provides new evidence for an immunopathogenic origin for fibroelastolytic papulosis and further supports current theories of the pathogenesis of Wolf isotopic response.

Acral Amelanotic Melanoma Mimicking a Foot Ulcer

Acral amelanotic melanoma can be difficult to diagnose and is often clinically aggressive. The present report describes a case of an acral amelanotic melanoma presenting as a non-healing wound after mimicking a plantar wart for two years. The decision to biopsy a borderline-suspicious lesion on the lower extremity in an elderly individual must be weighed carefully, as lower extremity biopsy carries a risk of poor wound healing and other complications. We discuss clinical and epidemiologic features that can assist in deciding when to perform a biopsy in this setting and can improve the early detection of acral amelanotic melanoma.

Granuloma annulare-like eruption in chronic lymphocytic leukemia

We report a patient with new-onset ulcerated granuloma annulare with concomitant involvement of B-cell leukemia. A granuloma annulare-like eruption with concomitant B cell chronic lymphocytic leukemia involvement in the skin is extremely rare, as only three cases have been previously reported in the literature to our knowledge. Given the rarity of ulceration in conventional granuloma annulare, it is possible this finding may serve as a diagnostic clue for underlying malignancy.

Safety of light emitting diode-red light on human skin: Two randomized controlled trials

Therapeutic applications of light emitting diode-red light (LED-RL) are expanding, yet data on its clinical effects are lacking. Our goal was to evaluate the safety of high fluence LED-RL (≥160 J/cm² ). In two phase I, single-blind, dose escalation, randomized controlled trials, healthy subjects received LED-RL or mock irradiation to the forearm thrice weekly for 3 weeks at fluences of 160-640 J/cm² for all skin types (STARS 1, n = 60) and at 480-640 J/cm² for non-Hispanic Caucasians (STARS 2, n = 55). The primary outcome was the incidence of adverse events (AEs). The maximum tolerated dose was the highest fluence that did not elicit predefined AEs. Dose-limiting AEs, including blistering and prolonged erythema, occurred at 480 J/cm² in STARS 1 (n = 1) and 640 J/cm² in STARS 2 (n = 2). AEs of transient erythema and hyperpigmentation were mild. No serious AEs occurred. We determined that LED-RL is safe up to 320 J/cm² for skin of color and 480 J/cm² for non-Hispanic Caucasian individuals. LED-RL may exert differential cutaneous effects depending on race and ethnicity, with darker skin being more photosensitive. These findings may guide future studies to evaluate the efficacy of LED-RL for the treatment of various diseases.

Radiation induced lichen planus - an uncommon side effect

Cutaneous lichen planus is classically characterized by violaceous, pruritic, planar papules and plaques, most commonly affecting the extremities. Lichen planus following radiation therapy is extremely rare and lichen planus following radiation therapy for prostate carcinoma has not been previously reported in the literature. We report a 66-year-old man who presented to the dermatology clinic with a symmetric pruritic eruption affecting the pelvic and gluteal region within two months of radiation therapy targeting the prostate and pelvic lymph nodes for prostate adenocarcinoma. The patient did not have a prior history of lichen planus. Physical examination demonstrated well demarcated, violaceous papules and plaques in a circumferential band-like distribution on the bilateral gluteal, lumbosacral, and pelvic region. In addition, he had a few discrete lesions on the calves and dorsal feet. Punch biopsy revealed an acanthotic epidermis with "saw-tooth" rete ridges and a lichenoid inflammatory infiltrate. A diagnosis of hypertrophic lichen planus was made, reinforcing the importance for clinicians to recognize radiation therapy as a risk factor for developing lichen planus despite no prior history of lichen planus.

Limb salvage of the foot with Lisfranc amputation following squamous cell carcinoma

The indolent character of squamous cell carcinoma of the foot can be misleading and might result in unwarranted excisions or delayed treatment.

Psoriasiform Pemphigus Foliaceus in an African American Female: An Important Clinical Manifestation

A 50-year-old African-American woman presented to the dermatology clinic with a pruritic eruption of 3 years' duration. On clinical examination, the patient had well-demarcated, pink, atrophic plaques and superficial erosions over the inframammary folds and mid-chest. She also had well-demarcated, hyperpigmented, hyperkeratotic scaly plaques over the abdomen, suprapubic region, elbows, knees, and back with sporadic small superficial blisters. A punch biopsy of the right abdomen was performed and revealed psoriasiform epidermal hyperplasia, focal parakeratosis, and acantholysis throughout the superficial spinous and granular layers. Only a sparse inflammatory infiltrate was present in the underlying dermis. Clinical and histological findings supported the diagnosis of pemphigus foliaceus (PF), but psoriasis was included in the differential diagnosis due to the presence of discrete plaques with an erythematous border. We hypothesize that patients with psoriasiform presentations of PF may be misdiagnosed with plaque psoriasis. It is important to distinguish between PF and psoriasis as there is evidence that ultraviolet light, a common treatment for psoriasis, may exacerbate PF. We document and highlight this atypical psoriasiform presentation of PF in a patient with skin of color to raise awareness and improve diagnosis and outcomes. <p><em>J Drugs Dermatol. 2018;17(4):471-473.</em></p>.

Fluoroscopy-induced radionecrosis

Complications from radiation exposure during fluoroscopic guidance of cardiac catheterization may occur. With repeated procedures, the risk for cutaneous injuries increases. Herein, we describe a 59-year-old man with extensive coronary artery disease, who had undergone multiple revascularization procedures and developed a non-healing ulcer on his left inferior scapula. The patient's medical history, physical exam findings, and histopathology gave clues to a case of radiation-induced dermatitis and necrosis.

Multiple Hereditary Infundibulocystic Basal Cell Carcinoma Syndrome Associated With a Germline SUFU Mutation

IMPORTANCE

Multiple hereditary infundibulocystic basal cell carcinoma syndrome (MHIBCC) is a rare genodermatosis in which numerous indolent, well-differentiated basal cell carcinomas develop primarily on the face and genitals, without other features characteristic of basal cell nevus syndrome. The cause is unknown. The purpose of the study was to identify a genetic basis for the syndrome and a mechanism by which the associated tumors develop.

OBSERVATIONS

Whole-exome sequencing of 5 tumors and a normal buccal mucosal sample from a patient with MHIBCC was performed. A conserved splice-site mutation in 1 copy of the suppressor of fused gene (SUFU) was identified in all tumor and normal tissue samples. Additional distinct deletions of the trans SUFU allele were identified in all tumor samples, none of which were present in the normal sample.

CONCLUSIONS AND RELEVANCE

A germline SUFU mutation was present in a patient with MHIBCC, and additional acquired SUFU mutations underlie the development of infundibulocystic basal cell carcinomas. The downstream location of the SUFU gene within the sonic hedgehog pathway may explain why its loss is associated with relatively well-differentiated tumors and suggests that MHIBCC will not respond to therapeutic strategies, such as smoothened inhibitors, that target upstream components of this pathway.

The distribution of cutaneous metastases correlates with local immunologic milieu

BACKGROUND

Metastases to the skin are found with increased frequency at certain sites, such as the scalp, but the biological factors that influence this distribution are not understood.

OBJECTIVE

We aimed to compare the proportional frequency of metastases at various cutaneous locations with the immunologic microenvironments at those sites.

METHODS

We retrospectively identified all biopsy specimens of cutaneous metastases diagnosed at our institution from 1991 to 2014 (n = 1984) and mapped their anatomic distribution while controlling for regional surface area. Using a separate, mapped cohort of normal-appearing skin samples (n = 140), we measured the density of regulatory T cells, CD4(+) effector T cells, and CD8(+) T cells by flow cytometry.

RESULTS

Per unit surface area, cutaneous metastases arise most commonly on the head and neck, followed by the trunk, upper extremities, and lower extremities, respectively. Sites with more frequent metastases tend to contain a greater density of regulatory T cells and a lower proportion of CD8(+) T cells (P < .05).

LIMITATIONS

Immunologic factors were only assessed in control tissue and were not measured from patients with metastatic disease in this correlative single-center study.

CONCLUSION

The distribution of cutaneous metastases follows the distribution of regulatory and effector T cells in skin. Further studies are required to prove a mechanistic association between local immunologic factors and the development of cutaneous metastases.

Gingival pustules and sterile diffuse sclerosing osteomyelitis as a feature of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome

Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome represents the rare co-occurrence of sterile inflammatory osteoarticular disease in association with a variety of cutaneous manifestations. Oral involvement is uncommon. The etiology of SAPHO is complex and is likely the combined result of infectious, genetic, and immunologic factors. Due to diverse clinical presentations, SAPHO is difficult to diagnose. Here, we describe the case of a 74-year-old man, who had a history of SAPHO syndrome and presented with gingival pustules and sterile diffuse sclerosing osteomyelitis of the mandible. This is the first case report describing neutrophilic mucositis as a feature of SAPHO.

Atypical MRI features in soft-tissue arteriovenous malformation: a novel imaging appearance with radiologic-pathologic correlation

BACKGROUND

The absence of a discrete mass, surrounding signal abnormality and solid enhancement are imaging features that have traditionally been used to differentiate soft-tissue arteriovenous malformations from vascular tumors on MRI. We have observed that these findings are not uncommon in arteriovenous malformations, which may lead to misdiagnosis or inappropriate treatment.

OBJECTIVE

To estimate the frequency of atypical MRI features in soft-tissue arteriovenous malformations and assess their relationship to lesion size, location, tissue type involved and vascular architecture.

MATERIALS AND METHODS

Medical records, MRI and histopathology were reviewed in consecutive patients with soft-tissue arteriovenous malformations in a multidisciplinary vascular anomalies clinic. Arteriovenous malformations were divided into those with and without atypical MRI findings (perilesional T2 signal abnormality, enhancement and/or a soft-tissue mass). Lesion location, size, tissue involved and vascular architecture were also compared between groups. Tissue stains were reviewed in available biopsy or resection specimens to assess relationships between MRI findings and histopathology.

RESULTS

Thirty patients with treatment-naïve arteriovenous malformations were included. Fifteen lesions demonstrated atypical MRI. There was no difference in age, gender, lesion size or involved body part between the groups. However, more than half of the atypical lesions demonstrated multicompartmental involvement, and tiny intralesional flow voids were more common in atypical arteriovenous malformations. Histopathology also differed in atypical cases, showing densely packed endothelial cells with connective tissue architectural distortion and edema.

CONCLUSION

Arteriovenous malformations may exhibit features of a vascular tumor on MRI, particularly when multicompartmental and/or containing tiny internal vessels. These features are important to consider in suspected fast-flow vascular malformations and may have implications with respect to their treatment.

A case of hair re-pigmentation from a scalp melanoma

Hair re-pigmentation in adults is a rare phenomenon. We describe a 58-year-old woman who developed hair re-pigmentation on her vertex scalp as a marker of underlying melanoma. Histopathology revealed a nodular melanoma that was surrounding but not invading follicular epithelium. To our knowledge, there have only been 4 other previously published cases describing hair re-pigmentation in the setting of scalp melanoma. Focal hair re-pigmentation in adults should prompt a thorough evaluation for an underlying melanoma.

Absence of peripheral blood chimerism in graft-vs-host disease following orthotopic liver transplantation: case report and review of the literature

BACKGROUND

Graft-vs-host disease (GVHD) is a rare and often fatal complication of orthotopic liver transplantation (OLT). The skin is frequently involved early in disease progression, but clinical and histopathological features may be nonspecific, presenting a diagnostic challenge. While the detection of peripheral blood chimerism has been proposed as a diagnostic criterion for post-OLT GVHD, it is not known whether peripheral blood chimerism is an absolute requirement for the diagnosis.

MATERIALS AND METHODS

We report a case of a 57-year-old man who developed post-OLT GVHD with cutaneous, enteric, and bone marrow involvement. We also review the epidemiology, pathogenesis, clinical presentation, histopathology, molecular diagnostic techniques, and treatment of GVHD following liver transplantation.

RESULTS

In our patient, analysis of the peripheral blood by short-tandem repeat polymerase chain reaction did not detect circulating donor lymphocytes. Donor lymphocytes were detected in the buccal mucosa, however, confirming the diagnosis. A review of chimerism patterns in 63 previously published cases of post-OLT GVHD reveals that this is the first reported case in which chimerism was absent in the peripheral blood but present in another site.

CONCLUSIONS

Peripheral blood chimerism may be absent in cases of post-OLT GVHD. A combination of clinical, histopathological, and molecular features is therefore required to make this challenging diagnosis.

Reversible precipitation of bovine serum albumin by metal ions and synthesis, structure and reactivity of new tetrathiometallate chelating agents

Independent research is an important component of any undergraduate chemistry program. This article reports the findings of two of many undergraduate research projects directed by Ed Stiefel in the hopes that the results will be inspiring and useful to the scientific community. The neurological disorders associated with insufficient copper in Menkes disease and an excess of copper in Wilson's disease are well established; however, recent evidence suggests that copper may also be involved in other disorders, such as Alzheimer's, angiogenesis, and prion diseases. The exact role of copper, however, is uncertain. This study examines the role of copper and zinc in the formation of protein deposits and the chelation and removal of the metal ions to reverse the process. The bovine serum albumin (BSA) protein forms a precipitate after the addition of approximately 6 copper(II) atoms or 8 zinc(II) atoms. Other metal ions, such as Ca(II), Al(III), Ni(II), and Co(II), did not precipitate the BSA even when the metal ion to BSA ratios were in excess of 1000. The copper and zinc protein precipitates returned to solution after addition of the chelating agents, ethylenediaminetetraacetic acid (EDTA) or tetrathiometallates [(MS(4)(2-)), where M=Mo, W]. Two new choline and acetylcholine tetrathiomolybdate and tetrathiotungstate chelating agents have been synthesized and characterized. The infrared (IR) and X-ray crystal structures of the complexes revealed that the (MS(4)(2-)) cores had approximate T(d) symmetry in the choline (Ch) salts and C(2v) symmetry in the acetylcholine (AcCh) salts. The AcCh salts hydrolyzed more slowly than the ammonium or Ch salts and the tetrathiotungstate salts hydrolyzed approximately two orders of magnitude more slowly than the tetrathiomolybdate salts. The slower hydrolysis of tetrathiotungstate may make it more useful as an inorganic reagent and therapeutic agent.

Recognition of cholinergic agonists by the muscarinic receptor. 2. Pilocarpine

The conformational potential energy surface of the muscarinic agonist pilocarpine is studied by molecular mechanics (MMP2) and by semiempirical (AM1) and ab initio self-consistent-field (SCF) calculations. Six minima were located, two of which correspond to the known X-ray structures of pilocarpine. Possible active conformations of pilocarpine are inferred from the potential energy surfaces used in conjunction with the proposed active conformation of muscarine previously obtained from a theoretical model.

The two-modes-of-binding model for partial agonism and the design of partial agonists

A model of drug action is developed for a drug which can bind in two modes to a given receptor: an agonist mode which elicits a response and an antagonist mode which does not. It is shown that this combination of agonist and antagonist binding, which is tantamount to self-antagonism, can lead to agonist, partial agonist or antagonist behavior. The proposed two-modes-of-binding model has applications to the design of partial agonists. Finally, partial agonism arising from two modes of binding is indistinguishable from partial agonism occurring by two-state model mechanisms using experimental equilibrium studies.

Recognition of cholinergic agonists by the muscarinic receptor. 1. Acetylcholine and other agonists with the NCCOCC backbone

A theoretical model is used to deduce the pharmacologically active conformation of acetylcholine and other agonists interacting with the muscarinic receptor of the parasympathetic and central nervous systems. This is accomplished by replacing the usual dihedral angles tau 1 and tau 2, which define the conformations of cholinergic drugs, with two new geometric parameters more suitable for describing the muscarinic pharmacophore: a characteristic distance, [PQ], and a dihedral angle, PNOQ. Values for these parameters are determined by conformational analysis on semirigid muscarinic agonists using molecular mechanics and ab initio molecular orbital methods. In addition to deducing the active conformation of acetylcholine and other agonists, the model also rationalizes the pattern of stereoselectivity in agonists related to 3-acetoxyquinuclidine (aceclidine) and furnishes a geometric criterion for partial agonism and antagonism.