Extrafacial Merkel Cell Carcinoma Presenting as a Cyst.

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine skin tumor that presents as an erythematous or violaceous nodule in elderly white males with an extensive history of sun exposure. Herein, we report two cases of extrafacial MCC. On exam, lesions presented as a cystic nodule and a firm plaque. We summarize tools from literature review that may aid in earlier diagnosis of MCC as well as implications of primary tumor location in prognosis. In addition, we provide an algorithm for diagnostic workup. MCC is an aggressive malignancy with a poor prognosis and a high risk of local recurrence and nodal metastasis. It is imperative to include MCC in differential diagnosis of cyst/nodule in order to facilitate early detection. J Drugs Dermatol. 2022;21(3):304-308. doi:10.36849/JDD.6248.

Atypical cells on reflectance confocal microscopy may not represent melanoma: A case of axillary pigmented extramammary Paget disease.

Pigmented extramammary Paget disease (PEMPD) is a rare intraepithelial carcinoma which can clinically resemble other pigmented neoplasms. Similarities to melanoma on dermoscopy, histopathology, and reflectance confocal microscopy (RCM) increase the risk of misdiagnosis and, consequently, mismanagement. Here, we describe a case of a 67-year-old African American woman with a large, pigmented axillary patch that exhibited features of melanoma on RCM, guiding the clinician to perform an excisional biopsy. While traditional histopathology resembled melanoma, immunohistochemistry staining was performed and revealed PEMPD. We highlight an uncommon clinical presentation of PEMPD disease and identify morphologic mimickers of melanoma on RCM-as well as differentiating features.

Acral pigmented Spitz nevus in a child with transepidermal migration of melanocytes: Dermoscopic and reflectance confocal microscopic features.

Acral pigmented Spitz nevi are seldom reported in the literature. We report a new case on the palm of a 4-year-old girl that demonstrated correlation between features observed on dermoscopy and reflectance confocal microscopy (RCM). Histopathology revealed a benign intraepidermal Spitz nevus with transepidermal elimination of melanocytes that showed on RCM as focal atypical bright cells concerning for malignancy. This case is one of few reports in the literature combining dermoscopy, reflectance confocal microscopy, and histology for an acral Spitz nevi, which are rarely evaluated by RCM given the thickness of the stratum corneum in acral sites.

Imaging Tools for Noninvasive Hair Assessment.

Trichology tools historically have been limited in their ability to provide noninvasive detailed assessments of the hair and scalp. Recent advances in diagnostic and treatment monitoring technologies have begun to fill this gap. Global photography previously relied on a film camera and stereotactic imaging equipment but has been simplified by the advent of cameras that use software analysis and provide adjustable outlines to match facial features for the capture of standardized views. Reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) both enable in vivo visualization of subcutaneous structures and provide new insight into the dynamic subclinical changes of alopecia. Recent efforts focus on training convolutional neural networks to quantify various hair parameters on OCT scans. When scalp biopsy is necessary, trichoscopy, RCM, and OCT can guide in selecting biopsy sites. Because of the growing clinical applications of these technologies, clinicians should be aware of the advantages and limitations of noninvasive hair-imaging tools.

Identification of Legionella pneumophila serogroups and other Legionella species by mip gene sequencing.

The virulence factor known as the macrophage infectivity potentiator (mip) is responsible for the intracellular survival of Legionella species. In this study, we investigated the potential of the mip gene sequence to differentiate isolates of different species of Legionella and different serogroups of Legionella pneumophila. We used 35 clinical L. pneumophila isolates and one clinical isolate each of Legionella micdadei, Legionella longbeachae, and Legionella dumoffii (collected from hospitals all over Japan between 1980 and 2007). We used 19 environmental Legionella anisa isolates (collected in the Okinawa, Nara, Osaka, and Hyogo prefectures between 1987 and 2007) and two Legionella type strains. We extracted bacterial genomic DNA and amplified out the mip gene by PCR. PCR products were purified by agarose gel electrophoresis and the mip gene was then sequenced. The L. pneumophila isolates could be divided into two groups: one group was very similar to the type strain and was composed of serogroup (SG) 1 isolates only; the second group had more sequence variations and was composed of SG1 isolates as well as SG2, SG3, SG5, and SG10 isolates. Phylogenetic analysis displayed one cluster for L. anisa isolates, while other Legionella species were present at discrete levels. Our findings show that mip gene sequencing is an effective technique for differentiating L. pneumophila strains from other Legionella species.

Bullous Pemphigoid Following the Moderna mRNA-1273 Vaccine.

As the onset of novel variants of the severe acute respiratory syndrome coronavirus 2 virus pushes policy-makers to push widespread vaccination efforts, it is likely that an increased number of severe cutaneous adverse reactions (SCARs) will present. Therefore, it is important to understand the presentation of possible SCARs. However, data are limited regarding which SCARs are most likely to be found following vaccination, and specific presentations in certain demographic groups, such as postmenopausal women, remain widely unknown. Here, we present the case of a 73-year-old female with no medical history or allergies presenting with a unique reaction of systemic bullous pemphigoid following the Moderna mRNA-1273 vaccine. To our knowledge at the time of this writing, based on a thorough review of the literature using PubMed, no such cases exist following the Moderna vaccine in the United States in elderly, postmenopausal women. We present a brief discussion on the presentation and management to hopefully alleviate future morbidity from similar reactions with increased distribution of the vaccine.

Organizing pneumonia pattern in the follow-up CT of Legionella-infected patients.

The main aim of this study was to describe the appearance of the CT pattern of organizing pneumonia in Legionella-infected patients. Serial CT scans obtained from five sporadic cases of Legionella pneumophila pneumonia were retrospectively reviewed. The mean time of follow-up was 14 days. Chest CT was analyzed with regard to frequency and appearance of CT patterns of pulmonary abnormalities. Consolidation and ground-glass opacities, with or without an air bronchogram, were the most common abnormalities detected in CT scans during follow-up patients with L. pneumophila pneumonia. Two patterns were observed: subpleural and peribronchovascular. The subpleural pattern was seen in four patients and the peribronchovascular pattern in one. Interlobular septal thickening was seen in one patient. Pleural effusion was seen in one patient. The CT pattern of organizing pneumonia, a subpleural pattern, was frequently observed after treatment of L. pneumophila pneumonia.

Metabolic Acidosis, Hyperkalemia, and Renal Unresponsiveness to Aldosterone Syndrome: Response to Treatment with Low-Potassium Diet.

Gordon syndrome involves hyperkalemia, acidosis, and severe hypertension (HTN) with hypercalciuria, low renin and aldosterone levels. It is commonly observed in children and adolescents. Such patients respond successfully to sodium restriction and thiazide diuretics. In this article, we present three cases of metabolic acidosis, hyperkalemia, and renal unresponsiveness to aldosterone (MeHandRU Syndrome). All three patients did not have HTN or hypercalciuria and demonstrated normal renin and aldosterone levels. These patients did not respond to thiazide-type diuretic therapy and salt restriction. Two males (aged 55- and 62-year) and a female patient (aged 68-year) presented to the clinic with unexplained hyperkalemia (5.9 mEq/L, 5.9 mEq/L and 6.2 mEq/L, respectively). On physical examination, blood pressure (BP) was found to be normal (<140/90 mm Hg). Over the counter potassium supplement, nonsteroidal anti-inflammatory drugs, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, potassium sparing diuretic use, as well as hyporeninemic hypoaldosteronism states such as diabetes mellitus were excluded. Plasma renin and aldosterone levels were normal. All three patients had low transtubular potassium gradient, despite high serum potassium levels. None of the patients reported a family history of hyperkalemia or kidney failure. All failed to demonstrate a response to hydrochlorothiazide and salt restriction. After careful consideration, strict low potassium diet (<2 g/day) was initiated in consultation with the dietician. Diuretic therapy was discontinued while BP remained within normal range (<140/90 mm Hg). At eight weeks, all three patients demonstrated normalization of potassium and correction of acidosis. At follow-up of six months, all patients are maintaining a normal potassium level. We suggest that potassium restriction can be successful in patients presenting with MeHandRU syndrome.

Diagnostic Accuracy of Reflectance Confocal Microscopy for Diagnosis of Skin Lesions: An Update.

CONTEXT.­: Histopathology is the current standard to diagnose skin disease. However, biopsy may not always be feasible, such as in patients with multiple nevi, a patient with a lesion on an aesthetically significant site, or in children. Recently, noninvasive techniques, including reflectance confocal microscopy (RCM), optical coherence tomography, and Raman spectroscopy, have enabled dermatologists to manage skin lesions in real time without the need for biopsy. OBJECTIVE.­: To report the updated diagnostic accuracy of RCM for equivocal skin lesions. DESIGN.­: In this study, we retrospectively reviewed our data of clinically suspicious lesions from 2010 to 2017 that were evaluated by RCM. RESULTS.­: Our results showed an overall sensitivity of 98.2% and specificity of 99.8%. CONCLUSIONS.­: In conclusion, RCM is a noninvasive real-time tool with the potential to diagnose skin lesions with high accuracy and without biopsy.

In Vivo and Ex Vivo Microscopy: Moving Toward the Integration of Optical Imaging Technologies Into Pathology Practice.

The traditional surgical pathology assessment requires tissue to be removed from the patient, then processed, sectioned, stained, and interpreted by a pathologist using a light microscope. Today, an array of alternate optical imaging technologies allow tissue to be viewed at high resolution, in real time, without the need for processing, fixation, freezing, or staining. Optical imaging can be done in living patients without tissue removal, termed in vivo microscopy, or also in freshly excised tissue, termed ex vivo microscopy. Both in vivo and ex vivo microscopy have tremendous potential for clinical impact in a wide variety of applications. However, in order for these technologies to enter mainstream clinical care, an expert will be required to assess and interpret the imaging data. The optical images generated from these imaging techniques are often similar to the light microscopic images that pathologists already have expertise in interpreting. Other clinical specialists do not have this same expertise in microscopy, therefore, pathologists are a logical choice to step into the developing role of microscopic imaging expert. Here, we review the emerging technologies of in vivo and ex vivo microscopy in terms of the technical aspects and potential clinical applications. We also discuss why pathologists are essential to the successful clinical adoption of such technologies and the educational resources available to help them step into this emerging role.

Recurrent optic neuritis as the only manifestation of chronic hepatitis B virus flare: a case report.

BACKGROUND: Autoimmune reactions have been associated with acute hepatitis B virus infection. Among these optic neuritis is a rare presentation with only a handful of cases reported in the literature thus far. The pathophysiologic mechanism governing this phenomenon includes high levels of circulating immune complexes, tissue deposit, and complement activation cascade. CASE PRESENTATION: In this report, we present the case of a 46-year-old African American man with a past medical history of untreated chronic hepatitis B virus, diagnosed 5 years ago, who presented to our facility on two occasions with the chief compliant of blurry vision. He was diagnosed with optic neuritis associated with acute on chronic hepatitis B virus infection, where the recurrent visual impairment was the main presenting symptom. Because hepatitis constituted a relative contraindication for steroid therapy, our patient was solely treated with antiviral medication. Antiviral therapy resulted in complete resolution of his symptoms and improvement in his liver function. CONCLUSIONS: Further studies are necessary to conclusively establish whether antiviral therapy can be employed as the sole therapy in immune complex-mediated optic neuritis, in the setting of active recurrent hepatitis B infection.

Pregnancy and hemodialysis access: A case for patient satisfaction in favor of a tunneled dialysis catheter.

While an arteriovenous fistula is the best available access, many patients continue to rely on a tunneled hemodialysis catheter for dialysis therapy. Despite the highest risk of catheter-related bacteremia and associated morbidity and mortality, patients often prefer tunneled hemodialysis catheter to avoid pain associated with cannulation of an arteriovenous access. We report three tunneled hemodialysis catheter-dependent end-stage renal disease patients (age: 38, 35, 33 years), who became pregnant. Pregnancy was discovered at 10, 12 and 10 weeks of gestation. All three patients were switched to daily hemodialysis (six sessions/week) as soon as the pregnancy was discovered. The three patients had refused the placement of an arteriovenous access and expressed their strong preference for tunneled hemodialysis catheter. All had been educated about the risks and benefits of catheter, grafts, and fistulas. Patient preference was acknowledged and dialysis therapy was continued with tunneled hemodialysis catheter. Pregnancy was uneventful in two patients with the delivery of a healthy baby. The third patient had a miscarriage. Patient preference for tunneled hemodialysis catheter and satisfaction is important and can result in a successful outcome in pregnant patients. Nonetheless, in keeping with the National Kidney Foundation guidelines as well as the Fistula First, an arteriovenous fistula should be offered to hemodialysis patients. At the same time, patient's preference and wish should be respected and followed.

C3 Glomerulopathy and Atypical Hemolytic Uremic Syndrome: Two Important Manifestations of Complement System Dysfunction.

The advances in our understanding of the alternative pathway have emphasized that uncontrolled hyperactivity of this pathway causes 2 distinct disorders that adversely impact the kidney. In the so-called atypical hemolytic uremic syndrome (aHUS), renal dysfunction occurs along with thrombocytopenia, anemia, and target organ injury to multiple organs, most commonly the kidney. On the other hand, in the so-termed C3 glomerulopathy, kidney involvement is not associated with thrombocytopenia, anemia, or other system involvement. In this report, we present 2 cases of alternative pathway dysfunction. The 60-year-old female patient had biopsy-proven C3 glomerulopathy, while the 32-year-old female patient was diagnosed with aHUS based on renal dysfunction, thrombocytopenia, anemia, and normal ADAMTS-13 level. The aHUS patient was successfully treated with the monoclonal antibody (eculizumab) for complement blockade. The patient with C3 glomerulopathy did not receive the monoclonal antibody. In this patient, management focused on blood pressure and proteinuria control with an angiotensin-converting enzyme inhibitor. This article focuses on the clinical differences, pathophysiology, and treatment of aHUS and C3 glomerulopathy.

Using Reflectance Confocal Microscopy in Skin Cancer Diagnosis.

Biopsy and histologic evaluation have been the gold standard to diagnose skin tumors. Reflectance confocal microcopy (RCM) is a noninvasive, innovative diagnostic technique that enables visualization of different skin layers at an almost histologic resolution. RCM has been proven beneficial in management of various cutaneous lesions. This article highlights the clinical significance and future of RCM to diagnose common skin cancers. However, RCM cannot replace currently standard histopathologic diagnosis. More studies are required to better compare the sensitivity and specificity of skin cancer diagnosis using RCM.