Impact of alternative histopathology protocols in the dermatopathology laboratory: A prospective quality improvement study.

BACKGROUND: Histopathology protocols for processing dermatopathology specimens vary among laboratories. OBJECTIVE: To determine an optimal histopathology protocol to minimize cost and turnaround time (TAT) for biopsy specimens in a dermatopathology laboratory. METHODS: A prospective, 4-month study compared the mean cost and TAT of producing one versus two initial H&E slides, and zero versus three unstained slides that could be used for frequently used special or immunohistochemical (IHC) stains. RESULTS: For all cases, cost was lower for one versus two initial H&E slides, with an insignificant increase in TAT. Producing three vs zero unstained slides incurred higher cost, with no reduction in TAT. In a subset of cases in which frequently used special or IHC stains were performed, cost and TAT were optimized by producing one initial H&E and three unstained slides. CONCLUSION: A protocol of one initial H&E slide and zero unstained slides optimizes cost and TAT in our dermatopathology laboratory. Pigmented lesions and inflammatory dermatoses may benefit from the addition of unstained slides. Further study is needed to quantify this benefit and evaluate for other cases for which an alternative protocol is advantageous.

Somatic PIK3R1 variation as a cause of vascular malformations and overgrowth.

PURPOSE: Somatic activating variants in the PI3K-AKT pathway cause vascular malformations with and without overgrowth. We previously reported an individual with capillary and lymphatic malformation harboring a pathogenic somatic variant in PIK3R1, which encodes three PI3K complex regulatory subunits. Here, we investigate PIK3R1 in a large cohort with vascular anomalies and identify an additional 16 individuals with somatic mosaic variants in PIK3R1. METHODS: Affected tissue from individuals with vascular lesions and overgrowth recruited from a multisite collaborative network was studied. Next-generation sequencing targeting coding regions of cell-signaling and cancer-associated genes was performed followed by assessment of variant pathogenicity. RESULTS: The phenotypic and variant spectrum associated with somatic variation in PIK3R1 is reported herein. Variants occurred in the inter-SH2 or N-terminal SH2 domains of all three PIK3R1 protein products. Phenotypic features overlapped those of the PIK3CA-related overgrowth spectrum (PROS). These overlapping features included mixed vascular malformations, sandal toe gap deformity with macrodactyly, lymphatic malformations, venous ectasias, and overgrowth of soft tissue or bone. CONCLUSION: Somatic PIK3R1 variants sharing attributes with cancer-associated variants cause complex vascular malformations and overgrowth. The PIK3R1-associated phenotypic spectrum overlaps with PROS. These data extend understanding of the diverse phenotypic spectrum attributable to genetic variation in the PI3K-AKT pathway.

Generalized infantile myofibromatosis with visceral involvement presenting as diffuse hypopigmented macules at birth.

The initial clinical presentation of infantile myofibromatosis can vary from subtle skin changes to large tumors. Here, we describe a case of congenital generalized infantile myofibromatosis which presented with diffuse hypopigmented macules, some with subtle atrophy and telangiectasia. Further workup revealed visceral involvement which led to treatment with systemic chemotherapy. Awareness of this rare clinical presentation is crucial to expedite workup and treatment given the poor prognosis in infants with visceral involvement.

Reactive angioendotheliomatosis associated with antiphospholipid syndrome.

Reactive angioendotheliomatosis (RAE) is an uncommon, benign, antiproliferative condition associated with systemic diseases that may cause occlusion or inflammation of the vascular lumina. A link between antiphospholipid syndrome (APS) and RAE has been reported a few times in the literature. Herein, we present a unique case of RAE diagnosed in a patient with primary APS who was well-managed on warfarin and rituximab with no recent thrombotic events. As RAE can precede or follow a diagnosis of APS, the presence of the condition indicates a need to workup for APS and to ensure those with the condition are adequately anticoagulated. However, as demonstrated in this case, the condition can still occur in patients who are adequately anticoagulated.

Rubella Vaccine Persistence Within Cutaneous Granulomas in Common Variable Immunodeficiency Disorder.

Common variable immunodeficiency disorder is a primary immunodeficiency disorder characterized by reduced levels of serum immunoglobulins and impaired antibody response. This condition may be associated with development of noninfectious granulomatous dermatitis of the skin which may be disfiguring and destructive. There are no published guidelines for the treatment of cutaneous granulomas in this patient population. In recent studies, rubella virus-positive cells in granulomas were localized to M2 macrophages which have an important role in wound healing and the secretion of immunoregulatory cytokines. We present a case of treatment-refractory, disfiguring common variable immunodeficiency disorder-associated granulomatous dermatitis. Immunofluorescence microscopy of the biopsy specimen confirmed the presence of rubella vaccine capsid proteins in M2 macrophages within the granuloma, a newly recognized phenomenon in this patient population. This knowledge may serve to identify future therapeutic targets or preventative strategies for granulomatous dermatitis in patients with primary immunodeficiency disorder.

Cutaneous metastases of papillary renal cell carcinoma: A case report and review of the literature.

Papillary renal cell carcinoma (RCC) is an uncommon subtype of RCC that is typically encountered at early stages and has a high survival rate. Histopathology typically shows well-defined papillary architecture with tumor cells lining fibrovascular cores and can be further subdivided into type 1 and type 2 tumors based on cytology and genetic basis. Type 1 tumors have a single layer of basophilic cells and low nuclear atypia, while type 2 tumors have a pseudostratified layer of eosinophilic cells and high nuclear atypia. Some tumors have overlapping features of both types. We present a unique case of cutaneous metastases of papillary RCC with typical papillary architecture in the dermis and review the literature on this rare entity.

Serologic Abnormalities in Macular Lymphocytic Arteritis with Case Presentation.

Macular lymphocytic arteritis (MLA) is an indolent cutaneous small-medium-vessel vasculitis characterized by widespread asymptomatic livedo racemosa. A number of serologic abnormalities have been reported including an elevated erythrocyte sedimentation rate and antibodies associated with antiphospholipid antibody syndrome. We present a case of MLA with multiple serologic abnormalities, including those that have yet to be reported, such as anti-U1 ribonucleotide protein, anti-RNA polymerase III, anti-smith, and anti-proteinase 3 antibodies. We also provide a brief review of this unfamiliar entity with a focus on the appropriate workup.

Association of Persistent Rubella Virus With Idiopathic Skin Granulomas in Clinically Immunocompetent Adults.

Importance: Vaccine-derived and wild-type rubella virus (RuV) has been identified within granulomas in patients with inborn errors of immunity, but has not been described in granulomas of healthy adults. Objective: To determine the association between RuV and atypical granulomatous inflammation in immune-competent adults. Design, Setting, and Participants: This case series, conducted in US academic dermatology clinics from January 2019 to January 2021, investigated the presence of RuV in skin specimens using RuV immunofluorescent staining of paraffin-embedded tissue sections, real-time reverse-transcription polymerase chain reaction, whole-genome sequencing with phylogenetic analyses, and cell culture by the US Centers for Disease Control and Prevention. Rubella immunoglobulin G, immunoglobulin M enzyme-linked immunoassay, and viral neutralization assays were performed for the sera of immunocompetent individuals with treatment refractory cutaneous granulomas and histopathology demonstrating atypical palisaded and necrotizing granulomas. Clinical immune evaluation was performed. Main Outcomes and Measures: Identification, genotyping, and culture of vaccine-derived and wild-type RuV within granulomatous dermatitis of otherwise clinically immune competent adults. Results: Of the 4 total immunocompetent participants, 3 (75%) were women, and the mean (range) age was 61.5 (49.0-73.0) years. The RuV capsid protein was detected by immunohistochemistry in cutaneous granulomas. The presence of RuV RNA was confirmed by real-time reverse-transcription polymerase chain reaction in fresh-frozen skin biopsies and whole-genome sequencing. Phylogenetic analysis of the RuV sequences showed vaccine-derived RuV in 3 cases and wild-type RuV in 1. Live RuV was recovered from the affected skin in 2 participants. Immunology workup results demonstrated no primary immune deficiencies. Conclusions and Relevance: The case series study results suggest that RuV (vaccine derived and wild type) can persist for years in cutaneous granulomas in clinically immunocompetent adults and is associated with atypical (palisaded and necrotizing type) chronic cutaneous granulomas. These findings represent a potential paradigm shift in the evaluation, workup, and management of atypical granulomatous dermatitis and raises questions regarding the potential transmissibility of persistent live RuV.