Leprosy as a Diagnostic Challenge in the United States

A 63-year-old woman from Central Florida presented to an outside clinic with a 2-year history of a progressive, asymptomatic cutaneous eruption and arthralgias. Her past medical history was significant for reported seronegative rheumatoid arthritis, for which adalimumab, methotrexate, and low-dose prednisone therapy were initiated 5 years prior. The skin eruption occurred shortly after a 4-week hospitalization during which these medications were withheld. At her initial outside evaluation, a biopsy was performed and interpreted as subacute cutaneous lupus erythematosus (SCLE). She was treated with hydroxychloroquine without improvement. A repeat biopsy was reported as consistent with interstitial granulomatous dermatitis (IGD). There was no improvement with potent topical corticosteroids.

Pernio (Chilblains), SARS-CoV-2, and COVID Toes Unified Through Cutaneous and Systemic Mechanisms

Pernio or chilblains is characterized by erythema and swelling at acral sites (eg, toes and fingers), typically triggered by cold exposure. Clinical and histopathologic features of pernio are well described, but the pathogenesis is not entirely understood; vasospasm and a type I interferon (IFN-I) immune response are likely involved. During the coronavirus disease 2019 (COVID-19) pandemic, dermatologists have observed an increase in pernio-like acral eruptions. Direct causality of pernio due to COVID-19 has not been established in many cases because of inconsistent testing methods (often negative results) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, a form of COVID-19‒associated pernio (also called COVID toes) is probable because of increased occurrence, frequently in young patients with no cold exposure or a history of pernio, and reports of skin biopsies with positive SARS-CoV-2 immunohistochemistry. PubMed was searched between January 1, 2020, and December 31, 2020 for publications using the following keywords: pernio, chilblain, and acral COVID-19. On the basis of our review of the published literature, we speculate that several unifying cutaneous and systemic mechanisms may explain COVID-19‒associated pernio: (1) SARS-CoV-2 cell infection occurs through the cellular receptor angiotensin-converting enzyme 2 mediated by transmembrane protease serine 2, subsequently affecting the renin-angiotensin-aldosterone system with an increase in the vasoconstricting, pro-inflammatory, and prothrombotic angiotensin II pathway. (2) Severe acute respiratory syndrome coronavirus 2 cell infection triggers an immune response with robust IFN-I release in patients predisposed to COVID-19‒associated pernio. (3) Age and sex discrepancies correlated with COVID-19 severity and manifestations, including pernio as a sign of mild disease, are likely explained by age-related immune and vascular differences influenced by sex hormones and genetics, which affect susceptibility to viral cellular infection, the renin-angiotensin-aldosterone system balance, and the IFN-I response.

Cutaneous mesenchymal tumors treated with Mohs micrographic surgery: a comprehensive review

Cutaneous mesenchymal tumors (CMT) are rare tumors with wide clinicopathologic heterogeneity. Treatment of malignant cutaneous mesenchymal tumors traditionally includes wide local excision (WLE), though Mohs micrographic surgery (MMS) has been increasingly used. A PubMed literature review of articles from inception until September 2019 related to malignant CMT and surgical treatment with MMS or WLE was completed. Dermatofibrosarcoma protuberans treated with MMS recurred in 1.2% of patients with no reported metastasis. Atypical fibroxanthoma treated with MMS recurred and metastasized in 2.7 and 2.5%, respectively. Undifferentiated pleomorphic sarcoma treated with MMS recurred in 32% with an unknown metastatic rate. Superficial leiomyosarcoma treated with MMS recurred in 3.8% with no reported metastasis. Cutaneous angiosarcoma and myofibrosarcoma treated with MMS have shown no recurrence or metastatic disease, but literature is sparse. The rarity of malignant CMT and the lack of comparative data on treatment make conclusive treatment recommendations difficult. However, recent literature suggests MMS is a useful option and potentially a superior treatment for primary cutaneous mesenchymal tumors.

Identification of stage I/IIA melanoma patients at high risk for disease relapse using a clinicopathologic and gene expression model

PURPOSE

Patients with stage I/IIA cutaneous melanoma (CM) are currently not eligible for adjuvant therapies despite uncertainty in relapse risk. Here, we studied the ability of a recently developed model which combines clinicopathologic and gene expression variables (CP-GEP) to identify stage I/IIA melanoma patients who have a high risk for disease relapse.

PATIENTS AND METHODS

Archival specimens from a cohort of 837 consecutive primary CMs were used for assessing the prognostic performance of CP-GEP. The CP-GEP model combines Breslow thickness and patient age, with the expression of eight genes in the primary tumour. Our specific patient group, represented by 580 stage I/IIA patients, was stratified based on their risk of relapse: CP-GEP High Risk and CP-GEP Low Risk. The main clinical end-point of this study was five-year relapse-free survival (RFS).

RESULTS

Within the stage I/IIA melanoma group, CP-GEP identified a high-risk patient group (47% of total stage I/IIA patients) which had a considerably worse five-year RFS than the low-risk patient group; 74% (95% confidence interval [CI]: 67%-80%) versus 89% (95% CI: 84%-93%); hazard ratio [HR] = 2.98 (95% CI: 1.78-4.98); P < 0.0001. Of patients in the high-risk group, those who relapsed were most likely to do so within the first 3 years.

CONCLUSION

The CP-GEP model can be used to identify stage I/IIA patients who have a high risk for disease relapse. These patients may benefit from adjuvant therapy.

Model Combining Tumor Molecular and Clinicopathologic Risk Factors Predicts Sentinel Lymph Node Metastasis in Primary Cutaneous Melanoma

Purpose

More than 80% of patients who undergo sentinel lymph node (SLN) biopsy have no nodal metastasis. Here we describe a model that combines clinicopathologic and molecular variables to identify patients with thin and intermediate thickness melanomas who may forgo the SLN biopsy procedure due to their low risk of nodal metastasis.

Patients and Methods

Genes with functional roles in melanoma metastasis were discovered by analysis of next generation sequencing data and case control studies. We then used PCR to quantify gene expression in diagnostic biopsy tissue across a prospectively designed archival cohort of 754 consecutive thin and intermediate thickness primary cutaneous melanomas. Outcome of interest was SLN biopsy metastasis within 90 days of melanoma diagnosis. A penalized maximum likelihood estimation algorithm was used to train logistic regression models in a repeated cross validation scheme to predict the presence of SLN metastasis from molecular, clinical and histologic variables.

Results

Expression of genes with roles in epithelial-to-mesenchymal transition (glia derived nexin, growth differentiation factor 15, integrin β3, interleukin 8, lysyl oxidase homolog 4, TGFβ receptor type 1 and tissue-type plasminogen activator) and melanosome function (melanoma antigen recognized by T cells 1) were associated with SLN metastasis. The predictive ability of a model that only considered clinicopathologic or gene expression variables was outperformed by a model which included molecular variables in combination with the clinicopathologic predictors Breslow thickness and patient age; AUC, 0.82; 95% CI, 0.78-0.86; SLN biopsy reduction rate of 42% at a negative predictive value of 96%.

Conclusion

A combined model including clinicopathologic and gene expression variables improved the identification of melanoma patients who may forgo the SLN biopsy procedure due to their low risk of nodal metastasis.

Persistent dermatomal eruption on a leg

Unilateral linear capillaritis (ULC) is a rare variant of pigmented purpuric dermatoses (PPD) that is characterized by a linear or pseudo-dermatomal eruption on a single extremity. Although clinically distinct from the other PPD, it shares histopathologic features with this group. Herein, we present a man in his 50s who presented with asymptomatic macules and scaly papules on the left lower extremity in a linear distribution. The eruption persisted despite treatment with topical triamcinolone 0.1% and oral rutocide.

Eumycetoma caused by Cladophialophora bantiana in the United States

A female presented in the sixth decade of life with a history of undifferentiated small cell carcinoma of the right breast in clinical remission, status-post chemotherapy and resection 6 years previously, presented with a chronic anterior knee skin nodule that grew in size over the prior 5–6 weeks. She had no history of opportunistic infections or recent immunosuppression. As it grew, the nodule became tender to touch. Examination revealed a 4–6 mm superficial purple-red nodule. Also, a similar lesion was present on the dorsum of her left foot for the past year, which also recently grew and became tender. The patient did report frequently kneeling on soil when gardening in Florida. She reported no other symptoms. Due to a concern for cutaneous metastasis of the patient’s previously diagnosed small cell carcinoma of the breast, the anterior knee lesion was biopsied. Histology revealed histocyte-rich inflammation with foci of acute inflammation as well as pigmented fungal forms. Subsequent fungal culture of excised tissue grew Cladophialophora bantiana, identified by ribosomal gene DNA sequencing.

Cutaneous lesions of angioimmunoblastic T-cell lymphoma: Clinical, pathological, and immunophenotypic features

BACKGROUND

Angioimmunoblastic T-cell lymphoma (AITL) is a systemic peripheral T-cell lymphoma with a follicular helper T-cell (T_FH ) immunophenotype that frequently involves the skin. However, the histopathology of cutaneous involvement by AITL has not been fully established.

METHODS

We reviewed the clinicopathological features of 19 patients seen at our institution with AITL involving the skin. Pan-T-cell and T_FH marker expression was evaluated by immunohistochemistry. Epstein-Barr virus (EBV) was detected using in situ hybridization (ISH) for Epstein-Barr virus-encoded small RNA (EBER). T-cell receptor (TCR) gene rearrangement was evaluated by PCR.

RESULTS

AITL affected both trunk and extremities in 15/19 cases (79%). Perivascular infiltration by small and/or medium-sized lymphocytes was seen in 18/19 (95%). Granulomatous inflammation was identified in 4/19 (21%). Aberrant loss of CD2, CD5, or CD7 was identified in 1/18 (6%), 2/18 (11%), or 7/19 (37%) cases, respectively. Seventeen of eighteen evaluable cases (95%) expressed 2 to 3 T_FH markers: PD-1 in 19/19 (100%), BCL6 in 94% (17/18), and CD10 in 37% (7/19). EBV-positive cells were detected in 3/18 (17%) with varying density. Clonal TCR gene rearrangement was identified in 9/11 (82%).

CONCLUSIONS

Cutaneous involvement by AITL shows relatively non-specific histopathological features. However, an immunohistochemical panel including T_FH markers and EBER ISH is useful in differential diagnosis.

Bi-allelic Alterations in AEBP1 Lead to Defective Collagen Assembly and Connective Tissue Structure Resulting in a Variant of Ehlers-Danlos Syndrome

AEBP1 encodes the aortic carboxypeptidase-like protein (ACLP) that associates with collagens in the extracellular matrix (ECM) and has several roles in development, tissue repair, and fibrosis. ACLP is expressed in bone, the vasculature, and dermal tissues and is involved in fibroblast proliferation and mesenchymal stem cell differentiation into collagen-producing cells. Aebp1-/- mice have abnormal, delayed wound repair correlating with defects in fibroblast proliferation. In this study, we describe four individuals from three unrelated families that presented with a unique constellation of clinical findings including joint laxity, redundant and hyperextensible skin, poor wound healing with abnormal scarring, osteoporosis, and other features reminiscent of Ehlers-Danlos syndrome (EDS). Analysis of skin biopsies revealed decreased dermal collagen with abnormal collagen fibrils that were ragged in appearance. Exome sequencing revealed compound heterozygous variants in AEBP1 (c.1470delC [p.Asn490_Met495delins(40)] and c.1743C>A [p.Cys581∗]) in the first individual, a homozygous variant (c.1320_1326del [p.Arg440Serfs∗3]) in the second individual, and a homozygous splice site variant (c.1630+1G>A) in two siblings from the third family. We show that ACLP enhances collagen polymerization and binds to several fibrillar collagens via its discoidin domain. These studies support the conclusion that bi-allelic pathogenic variants in AEBP1 are the cause of this autosomal-recessive EDS subtype.

Tumor Cell Adhesion As a Risk Factor for Sentinel Lymph Node Metastasis in Primary Cutaneous Melanoma

PURPOSE

Less than 20% of patients with melanoma who undergo sentinel lymph node (SLN) biopsy based on American Society of Clinical Oncology/Society of Surgical Oncology recommendations are SLN positive. We present a multi-institutional study to discover new molecular risk factors associated with SLN positivity in thin and intermediate-thickness melanoma.

PATIENTS AND METHODS

Gene clusters with functional roles in melanoma metastasis were discovered by next-generation sequencing and validated by quantitative polymerase chain reaction using a discovery set of 73 benign nevi, 76 primary cutaneous melanoma, and 11 in-transit melanoma metastases. We then used polymerase chain reaction to quantify gene expression in a model development cohort of 360 consecutive thin and intermediate-thickness melanomas and a validation cohort of 146 melanomas. Outcome of interest was SLN biopsy metastasis within 90 days of melanoma diagnosis. Logic and logistic regression analyses were used to develop a model for the likelihood of SLN metastasis from molecular, clinical, and histologic variables.

RESULTS

ITGB3, LAMB1, PLAT, and TP53 expression were associated with SLN metastasis. The predictive ability of a model that included these molecular variables in combination with clinicopathologic variables (patient age, Breslow depth, and tumor ulceration) was significantly greater than a model that only considered clinicopathologic variables and also performed well in the validation cohort (area under the curve, 0.93; 95% CI, 0.87 to 0.97; false-positive and false-negative rates of 22% and 0%, respectively, using a 10% cutoff for predicted SLN metastasis risk).

CONCLUSION

The addition of cell adhesion-linked gene expression variables to clinicopathologic variables improves the identification of patients with SLN metastases within 90 days of melanoma diagnosis.

Congenital and infantile benign skin lesions affecting the hand and upper extremity, part 2: nonvascular neoplasms

This article is part 2 of a 2-part series presented to aid the hand surgeon in becoming familiar with dermatological lesions that may be present on the upper extremity during infancy. The discussion focuses on nonvascular neoplasms grouped into the following categories: epithelial, melanocytic, histiocytic, dermal, fibroblastic, and adipocytic neoplasms. Diagnostic tips are offered, including clinical photographs, to help differentiate between these lesions. In addition, the recommended treatment for each is discussed.

Congenital and infantile skin lesions affecting the hand and upper extremity, part 1: vascular neoplasms and malformations

Many dermatologic conditions may be present on a newborn infant's upper extremity that can evoke concern for parents and/or primary caregivers. Although the pediatrician typically remains the first care provider, often these children are referred to specialists to diagnose and treat these lesions. Hand surgeons should be familiar with different infantile skin lesions on an upper extremity. Some lesions are best observed, whereas others require treatment with nonoperative measures, lasers, or surgical interventions. A 2-part series is presented to aid the hand surgeon in becoming familiar with these lesions. This part 1 article focuses on vascular neoplasms and malformations. Particular attention is paid to the multiple types of hemangiomas and hemangioendotheliomas, telangiectasias, angiokeratomas, as well as capillary, venous, and lymphatic malformations. Diagnostic tips and clinical photographs are provided to help differentiate among these lesions. In addition, the recommended treatment for each is discussed.

Benign subungual tumors

A variety of benign and malignant processes may affect the subungual region; however, most are relatively rare lesions. We present a review of the current literature regarding benign tumors affecting the subungual region.

Benign acquired superficial skin lesions of the hand

Numerous dermatologic conditions may be visualized by the hand surgeon during office hours, including when examining patients for an alternative chief problem. Although the primary focus of the visit may be unrelated to a skin lesion, it is important for the hand surgeon to be familiar with these lesions to address patient inquiries and determine which lesions may require some form of treatment. This article reviews some of the most common benign acquired superficial skin lesions of the hand. Particular attention will be paid to epidermal lesions, pigmented lesions, vascular lesions, dermal fibrous/fibrohistiocytic lesions, and infections that can be confused with skin neoplasms or tumor-like conditions. Diagnostic clues, including photographs, will be provided for each lesion described, as well as the recommended treatment.

Acute generalized exanthematous pustulosis

Acute generalized exanthematous pustulosis is a cutaneous reaction pattern typically precipitated by medication exposure. It has an estimated incidence of 1 to 5 cases per million per year and can occur in all age groups. Diagnosis is based on typical rash morphology, histopathology, and clinical course. Treatment consists of withdrawing the causative agent and providing supportive care. Prognosis for full recovery is excellent. Patients should be counseled to avoid any future use of the causative medication.