Myelodysplasia cutis and VEXAS syndrome initially diagnosed as histiocytoid Sweet syndrome: A diagnostic pitfall.

Histiocytoid Sweet syndrome (H-SS) is a histopathological variant of Sweet syndrome (SS) defined by cutaneous infiltration of immature myeloid cells morphologically resembling histiocytes. The association of H-SS with underlying malignancy, particularly myelodysplastic syndromes, is well-established. Myelodysplasia cutis (MDS-cutis) has been proposed to describe cases historically diagnosed as H-SS but characterized by shared clonality of the myeloid infiltrate in skin and bone marrow. Therefore, identifying patients who might have MDS-cutis is critical for the management of the associated hematologic malignancy. VEXAS syndrome, an adult-onset autoinflammatory disease, should also be included in the histopathologic differential diagnosis of H-SS, as it shares clinical and pathologic features with MDS-cutis. Through the presentation of two cases, we aim to highlight the defining features and key clinical implications of MDS-cutis and VEXAS syndrome.

Digital dermatopathology implementation: Experience at a multisite academic institution.

BACKGROUND: Technology has revolutionized not only direct patient care but also diagnostic care processes. This study evaluates the transition from glass-slide microscopy to digital pathology (DP) at a multisite academic institution, using mixed methods to understand user perceptions of digitization and key productivity metrics of practice change. METHODS: Participants included dermatopathologists, pathology reporting specialists, and clinicians. Electronic surveys and individual or group interviews included questions related to technology comfort, trust in DP, and rationale for DP adoption. Case volumes and turnaround times were abstracted from the electronic health record from Qtr 4 2020 to Qtr 1 2023 (inclusive). Data were analyzed descriptively, while interviews were analyzed using methods of content analysis. RESULTS: Thirty-four staff completed surveys and 22 participated in an interview. Case volumes and diagnostic turnaround time did not differ across the institution during or after implementation timelines (p = 0.084; p = 0.133, respectively). 82.5% (28/34) of staff agreed that DP improved the sign-out experience, with accessibility, ergonomics, and annotation features described as key factors. Clinicians reported positive perspectives of DP impact on patient safety and interdisciplinary collaboration. CONCLUSIONS: Our study demonstrates that DP has a high acceptance rate, does not adversely impact productivity, and may improve patient safety and care collaboration.

Anetoderma in the Setting of a Hematologic Abnormality and COVID-19 Infection.

ABSTRACT: Anetoderma is an uncommonly reported dermatosis clinically characterized by discrete skin lesions resulting from elastic fiber loss within the dermis. Although primary anetoderma has been considered idiopathic, a range of associated disorders, particularly prothrombotic abnormalities, have been reported. We present a 79-year-old woman with a heterozygous Factor V Leiden mutation who developed anetoderma shortly after COVID-19 infection complicated by a thromboembolic event. Our patient adds to the literature on the occurrence of anetoderma in the setting of infection and/or a prothrombotic disorder.

Dysplastic nevus part I: Historical perspective, classification, and epidemiology.

Since the late 1970s, the diagnosis and management of dysplastic nevi have been areas fraught with controversy in the fields of dermatology and dermatopathology. Diagnostic uncertainty and lack of standardized nomenclature continue to propagate confusion among clinicians, dermatopathologists, and patients. In part I of this CME review article, we summarize the historical context that gave rise to the debate surrounding dysplastic nevi and review key features for diagnosis, classification, and management, as well as epidemiology. We discuss essentials of clinical criteria, dermoscopic features, histopathologic features, and the diagnostic utility of total body photography and reflectance confocal microscopy in evaluating dysplastic nevi, with emphasis on information available since the last comprehensive review a decade ago.

Dysplastic nevus part II: Dysplastic nevi: Molecular/genetic profiles and management.

Dermatologists frequently see patients with clinically atypical nevi and dermatopathologists interpret histologically dysplastic nevi on a near-daily basis, but there is great variability in the definition and management of such lesions. This part of the CME review focuses on information published since the previous comprehensive review (2012), with emphasis on molecular and genetic attributes of histologically dysplastic nevi and clinical management.

Clinical and histopathological features of hypereosinophilic syndrome with cutaneous involvement: The Mayo Clinic Experience.

BACKGROUND: Hypereosinophilic syndrome (HES) encompasses a group of diseases with blood hypereosinophilia and eosinophil-mediated organ dysfunction. HES-associated skin abnormalities, termed cutaneous HES (cHES) here, may influence diagnosis of HES. We sought to better define clinical and histopathological features of cHES. METHODS: We retrospectively reviewed clinical records and cutaneous histopathology of adult patients with HES evaluated at our institution from 2007 to 2018. RESULTS: Forty-one percent (61/150) patients with HES had cHES. The most common clinical morphologies were urticarial (30%) and eczematous (26%). Skin specimens most often showed a spongiotic pattern (31%) with abundant inflammation (50%) including eosinophils (85%). Two specimens (8%) showed interstitial granulomatous dermatitis, and two specimens showed eosinophilic fasciitis (8%). Vasculitis was not identified in any specimen. Eighty-four percent of patients with cHES had ≥1 other organ system involved: pulmonary 41%, ENT 26%, and nervous 23%. Sixty percent (53/89) of non-cHES patients had at least two organ systems involved. Cardiac or gastrointestinal involvement was more common in non-cHES than cHES (p < 0.05). CONCLUSION: Our review confirms that there are no specific clinical or histopathological cHES patterns, but HES should be considered in patients who have eczematous or urticarial reactions of unknown etiology and persistent peripheral hypereosinophilia.

Impact of adding an IgG4 conjugate to routine direct immunofluorescence testing for subepithelial and intraepithelial autoimmune blistering disorders.

BACKGROUND: Certain autoimmune bullous dermatoses are mediated by autoantibodies of the IgG4 subclass. We determined the diagnostic impact of adding IgG4 to our conventional direct immunofluorescence (DIF) panel. METHODS: For all cases submitted to our referral laboratory for DIF over 1 month (n = 630), we performed IgG4 testing and collected consecutive biopsy specimens showing definite or indeterminate linear or cell-surface deposition of IgG, IgG4, and/or C3. On retrospective blinded review, we classified the pattern and whether the findings were definite, indeterminate, or negative. When present, substantial background staining was recorded. RESULTS: Seventy DIF specimens met the inclusion criteria. Of 22 (31.4%) specimens equivocal for linear or cell-surface deposition, 9 (40.9%) had definitive IgG4 findings, either linear (3 of 14 equivocal linear cases; 21.4%) or cell-surface (6 of 8 equivocal cell-surface cases; 75.0%). Background deposition was substantial in 14 cases (20.0%) for IgG but in none for C3 or IgG4. CONCLUSION: IgG4 allowed the classification of over 40% of DIF cases that were otherwise equivocal by IgG and C3. IgG4 staining showed lower levels of non-specific background staining than IgG or C3. IgG4 appears to contribute most value in cases with cell-surface deposition or with equivocal linear IgG deposition and negative C3 results.

Kaposi sarcoma misdiagnosed as granuloma annulare: A case of mistaken identity.

The microscopic features of patch stage Kaposi sarcoma (KS) and interstitial granuloma annulare (GA) may be difficult to differentiate, because both may exhibit a subtle "busy" dermis due to infiltration of spindled cells between collagen bundles. The clinical distinction is particularly challenging in human immunodeficiency virus (HIV)-affected individuals, as the incidence of GA appears to be greater in the HIV-infected population. KS is the most common neoplasm in this population. Despite the significant decrease in the incidence of KS since the advent of highly active antiretroviral therapy (HAART), KS tends to occur with late onset and indolent progression in patients with preserved immune function and minimal viral load. We present a 47-year-old homosexual HIV-positive man, under virologic and immunologic control on long-term HAART therapy, with a 5-year history of progressive red-brown patches and plaques on the legs, feet, hands, and trunk. Prior skin biopsy specimens were interpreted as interstitial GA. Histopathology on new skin biopsy specimens along with review specimens supported the diagnosis of plaque and patch stages of KS, respectively, supported by immunohistochemical expression of human herpes virus-8 (HHV-8). This case underscores the importance of maintaining a high suspicion for KS in progressive, treatment-recalcitrant skin lesions, particularly in HIV-infected individuals.

Outcomes of Adjuvant Radiotherapy Following Negative Surgical Margins for Cutaneous Squamous Cell Carcinoma.

BACKGROUND: The role of adjuvant radiotherapy (ART) for cutaneous squamous cell carcinoma (cSCC) following negative surgical margins is unclear. OBJECTIVE: To retrospectively examine the clinical outcomes in a cohort of patients with cSCC who completed ART after Mohs micrographic surgery or wide local excision with negative margins. METHODS AND MATERIALS: After the institutional review board approval, a retrospective review was conducted of all patients with cSCC treated in the Mayo Clinic Department of Radiation Oncology from March 10, 1998, through April 26, 2013. Inclusion criteria were age >18 years, resection with negative histologic surgical margins, and completion of ART. RESULTS: Thirty-two patients met the inclusion criteria: 15 patients died, 12 without evidence of disease related to cSCC. Three patients developed recurrent disease, all with poorly differentiated cSCC, > 2 cm in clinical diameter, perineural invasion, and Brigham and Women's (BWH) stage T2b/T3; 2 of 3 patients were immunosuppressed; and 2 of 3 patients died of cSCC-related causes. CONCLUSION: These data suggest that the combination of surgical resection and ART is a reasonable option for Brigham and Women's T2b/T3 tumors.

Clinicopathologic and immunophenotypic features of eosinophilic fasciitis and morphea profunda: A comparative study of 27 cases.

BACKGROUND: Eosinophilic fasciitis (EF) and morphea profunda (MP) are inflammatory and sclerosing disorders of the subcutis that can exhibit clinical and pathologic presentations that overlap. OBJECTIVE: To identify clinicopathologic features that can be used to distinguish EF from MP. METHODS: We performed a retrospective review of 16 patients with EF and 11 patients with MP. Hematoxylin-eosin, CD123, CD34, and Verhoeff-Van Gieson stains were evaluated on skin biopsies that included the fascia. RESULTS: EF patients were more likely than MP patients to be men (P = .047), have forearm involvement (P = .003), and have peripheral eosinophilia (P < .01). Compared with MP patients, patients with EF were more likely to have fascia that contained eosinophils (P = .003), although eosinophils were absent in 3 (19%) patients with EF. Focal absence of CD34 staining was more prominent in the fascia of EF patients (P = .04). The extent of Verhoeff-Van Gieson staining did not differ between the 2 groups. Dermal sclerosis was not detected in many cases of EF and MP (56% and 36%, respectively). LIMITATIONS: This was a retrospective study at a single institution. CONCLUSION: Although EF and MP share clinical and pathologic features, our results indicate that the presence of eosinophils in the blood and fascia and focal loss of CD34 staining might be more suggestive of EF than MP.

Mycobacterium lepromatosis Lepromatous Leprosy in US Citizen Who Traveled to Disease-Endemic Areas.

We report Mycobacterium lepromatosis infection in a US-born person with an extensive international travel history. Clinical symptoms, histopathology, and management are similar to those of infections caused by M. leprae. Clinicians should consider this pathogen in the diagnosis of patients with symptoms of leprosy who have traveled to endemic areas.

Low-Grade Malignant Proliferating Tricholemmal Tumor Associated With Occult Ductal Carcinoma In Situ of the Breast.

Malignant proliferating tricholemmal tumor (MPTT) is a rare adnexal neoplasm most commonly located on the scalp. We a 62-year-old woman who presented to her local physician with a palpable but not visible nodule of the left breast, initially diagnosed as squamous cell carcinoma. Histopathological evaluation of the reexcision specimen incidentally revealed ductal carcinoma in situ. On referral to our institution, the skin biopsy specimen was reviewed and interpreted as a low-grade MPTT. This patient and 2 previously reported cases of MPTT involving breast skin highlight presentation of a rare tumor at an unusual site and the potential for misdiagnosis as squamous cell carcinoma. Reexcision provided the unexpected benefit for our patient of early diagnosis of ductal carcinoma in situ not revealed by imaging.

Cutaneous microemboli from hydrophilic polymer after endovascular procedures.

BACKGROUND: Multiple devices and coatings assist with endovascular insertion of sheaths, catheters, and guide wires. Hydrophilic polymer coatings, a common component of endovascular surgical devices, reportedly cause microvascular obstruction and embolization, with various sequelae in organs and soft tissue. OBJECTIVE: We sought to describe clinical and histopathologic features of cutaneous manifestations of hydrophilic polymer gel emboli. METHODS: We evaluated the clinical and histopathologic characteristics of 8 patients with cutaneous complications of hydrophilic polymer gel emboli who presented in May 2013 through February 2015. RESULTS: Sudden onset of lower extremity livedo racemosa, purpuric patches, or both, occurred hours to days after endovascular procedures involving the aorta. Histopathologic evaluation showed basophilic lamellated material, consistent with hydrophilic polymer gel emboli, within small dermal vessels. LIMITATIONS: This was a retrospective study with small sample size and not controlled for all similar procedures in this population. CONCLUSION: Hydrophilic polymer gel coatings in endovascular devices can embolize to skin and cause microvascular occlusion, presenting as livedo racemosa, purpura, or both. Given the number of patients observed over a short period, this phenomenon may be underappreciated. Hydrophilic polymer gel emboli should be considered in differential diagnosis of livedo racemosa and purpura after endovascular procedure.

Eosinophils in lichen sclerosus et atrophicus.

BACKGROUND: The classic histopathologic features of lichen sclerosus et atrophicus (LS) include lymphoplasmacytic inflammation below a zone of dermal edema and sclerosis. The presence of eosinophils in LS has received little attention, but the finding of tissue eosinophils, particularly eosinophilic spongiosis in LS, has been suggested as a marker for the coexistence of autoimmune bullous disease or allergic contact dermatitis (or both). We sought to determine whether the histopathologic presence of dermal eosinophils or eosinophilic spongiosis (or both) in biopsies from patients with LS is associated with autoimmune bullous disease, autoimmune connective tissue disease or allergic contact dermatitis. METHODS: A retrospective review of the histopathology and medical records of 235 patients with LS who were evaluated from June 1992 to June 2012 was performed. RESULTS: Sixty-nine patients (29%) had eosinophils on histopathology. Among patients with associated diseases, a statistically significant association between the eosinophil cohort and the cohort without eosinophils was not detected. CONCLUSIONS: The importance of eosinophils is uncertain, but our data suggest that the finding of tissue eosinophils alone is not sufficient to prompt an extensive workup for additional diagnoses.