Drug-Induced dermatomyositis following COVID-19 vaccination.

Dermatomyositis (DM) is a multi-organ idiopathic inflammatory myopathy that presents with proximal symmetric muscle weakness accompanied by characteristic cutaneous findings. Most individuals present with skin manifestations prior to muscle involvement and its course can involve the blood vessels, joints, esophagus, and lungs and can be paraneoplastic, making a malignancy assessment imperative. Although its etiology is unknown, type I interferon appears to be a component in evoking the characteristic inflammatory response and patients with DM often have an increase in type I inducible genes. Suspected triggers for DM are environmental factors, drugs, viral infections, and vaccines. The association of DM with vaccination poses a new conundrum within the medical community as people continue to get vaccinated and boosted with SARS-CoV2 vaccines, though it is worth noting that the most common challenges arose as type I hypersensitivity reactions and new onset autoimmune disorders are rare. Presented here is a 53-year-old man who was diagnosed with DM after receiving the second dose of the Pfizer vaccine. His case highlights the importance of the potential onset of autoimmune diseases following the COVID-19 vaccine, a phenomenon that clinicians should be aware of as the discourse concerning the pandemic continues.

A Single-Institution Cohort Study With Nevi of Special Site: Recurrence, Progression to Melanoma, and Patterns of Management.

ABSTRACT: Nevi of specialized sites (NOSS) occur on the scalp, ears, flexural, acral, and genital areas and display atypical clinical and histologic features. We assessed NOSS recurrence and progression to melanoma, management patterns, and associations between histologic features and treatment recommendations. We queried all histologic diagnoses of NOSS (n = 275) from 2012 to 2017 from a large U.S. academic medical center with reference dermatopathology laboratory and matched these to clinical records. A blinded panel of dermatopathologists re-evaluated lesions, catalogued histologic findings, and gave management recommendation. Associations with dermatopathologist decision and concordance between new and original recommendations were assessed. Of 117 cases with follow-up, 2 locally recurred (1.46%) and none eventuated in melanoma. Clinical features were not associated with original treatment recommendations. After histopathologic review, large melanocytes [odds ratio ratio (ORR) = 8.00, 95% CI, 1.35-47.4] and junctional mitotic figures (ORR = 65.0, 6.5-650) predicted excision recommendation. Likewise, accumulation of many (>9) high-risk features was associated with excision recommendation. Panel review changed treatment recommendation in 27% of cases. Fair concordance existed between original and panel recommendations (κ = 0.29, 0.15-0.44). The low rate of recurrence and lack of melanoma occurrence suggest that despite an atypical clinical and histopathologic appearance, these nevi have limited potential for malignant transformation. Histopathologic findings seem to be principal drivers behind the recommendation for excision in this analysis. Variability existed in treatment recommendations; the panel's consensus recommendation tended to downgrade treatment. This highlights the importance of further outcomes-based studies to identify true high-risk features and refine management guidelines.

Cutaneous metastasis as a first sign of adenocarcinoma of the cervix.

Cervical cancer remains one of the most common malignancies diagnosed in women as well as a leading cause of cancer related deaths in women worldwide. Cutaneous metastasis associated with cervical malignancy is a remarkably rare phenomenon. We present a patient whose cutaneous signs led to the diagnosis of metastatic adenocarcinoma of the cervix.

Pretibial Pruritic Papular Dermatitis: A Comprehensive Clinical and Pathologic Review of Cases at a Single Institution.

BACKGROUND: Studies characterizing clinical and pathologic details of pretibial pruritic papular dermatitis (PPPD) are scarce. Several cases of PPPD at our institution have displayed lymphocyte atypia and CD30 positivity, resembling lymphomatoid papulosis (LyP). We explore the clinical and histological spectrum of PPPD, with emphasis on lymphocyte atypia. METHODS: Retrospective observational study of 40 archived pathological specimens (hematoxylin/eosin, CD3, CD20, and CD30 immunohistochemistry) from 38 PPPD patients in an academic center. Clinical photographs were available in 22 cases. RESULTS: Microscopic epidermal changes were focal, but common (spongiosis 75%, parakeratosis 90%, interface changes 43%, Langerhans cell microgranulomas 25%, multinucleated keratinocytes 55%, Civatte bodies 55%, erosion 20%, and more than focal irregular psoriasiform hyperplasia 37%) and certain dermal changes were universal (papillary dermal fibrosis 100%, stellate fibroblasts 100%, and multinucleated fibroblasts 93%). At least focal lymphocyte atypia was present in all cases. Lymphocytes were almost exclusively CD3 T cells with rare CD20 B cells. Up to 30% of lymphocytes exhibited weak CD30 staining. Clinically, all cases exhibited discrete papules, but plaques and erosions were not uncommon. LIMITATIONS: As a retrospective series, clinical images were not available for all cases. CONCLUSION: This study suggests a broader histological and clinical spectrum of PPPD than previously described. Epidermal changes are common in PPPD, as are atypical lymphocytes and focal CD30 positivity. Although the papular clinical appearance, lymphocyte atypia, and focal CD30 positivity may resemble LyP, the relatively low number of atypical lymphocytes, low intensity of CD30 staining, and absence of spontaneous resolution help to distinguish PPPD from LyP.

Histopathologic vasculitis from the periulcer edge: A retrospective cohort study.

BACKGROUND: Histopathologic vasculitis is often reported in periulcer specimens, but the frequency and clinical significance of this finding have not been evaluated. OBJECTIVE: We evaluated the sensitivity, specificity, negative predictive value, and positive predictive value of histopathologic vasculitis from the periulcer edge for detecting ulcers due to cutaneous vasculitis. METHODS: We performed a retrospective chart review of patients with leg ulcers at a tertiary hospital between 2009 and 2016. Histopathologic slides were evaluated by 2 dermatopathologists who were blinded to the etiology of ulcer. Focal vasculitis was defined as involvement of fewer than 3 vessels. RESULTS: Vasculitis at the periulcer edge was seen in 51.6% of the specimens (32 of 62). Of the specimens with histopathologic vasculitis, focal vasculitis was seen in the majority of specimens (71.9% [23 of 32]), whereas diffuse vasculitis was observed in 28.1% (9 of 32). Periulcer vasculitis yielded a high sensitivity (100% [95% confidence interval, 29%-100%]). Furthermore, the specificity was low (50.9% [95% confidence interval, 38.1%-63.6%]) for detecting vasculitis-induced ulcers. LIMITATIONS: Small number of vasculitis-induced ulcers. CONCLUSION: Focal vasculitis from the periulcer edge is a nonspecific finding and provides little diagnostic value in determining the etiology of lower leg ulcers. Emphasis should be placed on the combination of clinical history and examination, histology, and laboratory findings when diagnosing ulcers.

Capillary hemangioma associated with dermal atrophy masquerading as a deep fungal infection.

Hemangiomas are benign vascular neoplasms which arise in early adulthood. Herein we present a 79-year-old woman with a hemangioma of the lower flank masquerading as a cutaneous manifestation of a systemic fungal infection upon initial histological analysis. Decreased elastin and collagen within the lesion likely accounted for the clumping and splaying of the capillaries into "hyphae-like" structures. Loss of dermal elastic tissue and collagen apparently concentrated the capillary proliferation into an unusual morphology mimicking the hyphal structures. Through additional staining methods the lesion was confirmed to be an unusual presentation of a capillary hemangioma.

Cutaneous carcinosarcoma: a series of six cases and a review of the literature.

BACKGROUND: Cutaneous carcinosarcoma is a rare tumor with distinct malignant epithelial and mesenchymal cell populations. The histologic subtypes of epithelial and mesenchymal components in cutaneous carcinosarcoma are variable, as an assortment of carcinomatous and sarcomatous patterns have been described in the literature. METHODS: Clinical information was obtained from patient charts and archival slides were retrieved and reviewed. RESULTS: We present a novel series of six distinct cases of cutaneous carcinosarcoma and review the literature. Our cases consisted of basal cell, pilomatrical, squamous cell, and trichoblastic variants. These cases occurred in elderly men on sun exposed skin with treatment and follow up was available for 4 of 6 cases. The four cases were treated with Mohs micrographic surgery with mean follow up of nine months. CONCLUSION: We report six cases of cutaneous carcinosarcoma with distinctive clinical and histologic characterization not previously described in a single series.

Predictive value of biopsy specimens suspicious for melanoma: support for 6-mm criterion in the ABCD rule.

OBJECTIVE: Clinical detection of melanoma can be challenging. The number of biopsy specimens performed to diagnose 1 melanoma is a measure of efficiency of skin cancer detection, but few data are available to describe this measure from US health care. We studied the diagnosis of melanoma among biopsy specimens of clinically concerning pigmented lesions at an academic dermatology department. METHODS: We searched for all biopsy specimens that were performed because of clinical suspicion of melanoma in 2013. Characteristics of the patient, lesion, and clinician performing the biopsy, and the final pathology diagnosis were recorded. RESULTS: A total of 2643 biopsy specimens from 2213 patients submitted by 43 providers were included. Melanoma was diagnosed in 165 cases (positive predictive value 6.4%, 95% confidence interval 5.5%-7.4%). Older age (P < .001), male gender (P = .045), and nontrunk location (P < .001) were predictors of higher probability of melanoma detection. Lesions larger than 6 mm in size had higher positive predictive value 11.5% (8.8%-14.1%) than smaller lesions 2.6% (1.6%-3.6%). LIMITATIONS: Factors influencing the decision to biopsy a lesion may be difficult to evaluate retrospectively. CONCLUSION: At an academic medical center, 16 clinically concerning lesions were biopsied to diagnose 1 melanoma. Biopsy specimens of clinically concerning pigmented lesions larger than 6 mm on older men had the highest yield.

Benign melanocytic lymph node deposits in the setting of giant congenital melanocytic nevi: the large congenital nodal nevus.

BACKGROUND: Benign melanocytic rests are a frequent finding in superficial lymph nodes removed during sentinel lymph node biopsies for melanoma. Whereas the histopathology of these deposits is well understood, very little is known regarding melanocytic lymph node deposits in the setting of giant congenital melanocytic nevi. METHODS: We analyzed lymph nodes removed from the drainage basin of giant congenital melanocytic nevi in three patients who had developed melanoma within their giant congenital nevi. RESULTS: Two of three patients showed widespread, capsular and parenchymal melanocytic deposits in multiple nodes (9 of 11 nodes in one patient and 6 of 8 in the other). Melanocytes were small, non-mitotically active and resembled those in the associated giant congenital melanocytic nevus. Melanocytes were arranged singly and in small nests ∼0.05 mm in diameter, with some larger sheets up to 1 mm. Nodal melanocytes stained for Melan A and S100 on immunohistochemical evaluation, but showed negative or minimal HMB-45 reactivity. CONCLUSIONS: Evaluation of lymph nodes in the setting of giant congenital melanocytic nevi is complicated by the presence of often numerous, parenchymal melanocytic nevic deposits. Bland cytology and minimal or absent HMB-45 staining may be helpful in differentiating these nodal melanocytic nevi from metastatic melanoma. We term this phenomena large congenital nodal nevus.

Clinical validation of a gene expression signature that differentiates benign nevi from malignant melanoma.

BACKGROUND: Histopathologic examination is sometimes inadequate for accurate and reproducible diagnosis of certain melanocytic neoplasms. As a result, more sophisticated and objective methods have been sought. The goal of this study was to identify a gene expression signature that reliably differentiated benign and malignant melanocytic lesions and evaluate its potential clinical applicability. Herein, we describe the development of a gene expression signature and its clinical validation using multiple independent cohorts of melanocytic lesions representing a broad spectrum of histopathologic subtypes. METHODS: Using quantitative reverse-transcription polymerase chain reaction (PCR) on a selected set of 23 differentially expressed genes, and by applying a threshold value and weighting algorithm, we developed a gene expression signature that produced a score that differentiated benign nevi from malignant melanomas. RESULTS: The gene expression signature classified melanocytic lesions as benign or malignant with a sensitivity of 89% and a specificity of 93% in a training cohort of 464 samples. The signature was validated in an independent clinical cohort of 437 samples, with a sensitivity of 90% and specificity of 91%. CONCLUSIONS: The performance, objectivity, reliability and minimal tissue requirements of this test suggest that it could have clinical application as an adjunct to histopathology in the diagnosis of melanocytic neoplasms.

Neutrophilic sebaceous adenitis with intralobular Demodex mites: a case report and review of the literature.

A 61-year-old white man presented with a 1-week history of an asymptomatic erythematous, annular plaque with minimal scale limited to the nasal bridge. Histological examination showed a mixed infiltrate of lymphocytes and neutrophils within sebaceous glands. The clinical and histopathological presentation was consistent with a diagnosis of neutrophilic sebaceous adenitis. Several Demodex brevis mites were present deep within the affected sebaceous lobules. Demodex brevis mites are uncommon inhabitants of sebaceous glands of the nose, presenting more commonly on other body sites. The cause of neutrophilic sebaceous adenitis is unknown, but the presence of D. brevis in affected sebaceous glands in this case suggests a possible association.

Secondary diffuse large B-cell lymphoma after chemotherapy for acute myeloid leukemia: looking for the unexpected diagnosis.

Development of Epstein-Barr virus (EBV) positive lymphoproliferative disorders in patients with immunosuppression has become more frequently reported. A patient with acute myeloid leukemia was treated to remission, when on follow-up 9 months after his initial diagnosis, he was noted to have a generalized rash and lymphadenopathy. Evaluation of skin and bone marrow biopsies was suggestive of a relapsed leukemia, and treatment was initiated. Fever evaluation revealed a high load of EBV in his blood. A lymph node biopsy and retrospective examination of his skin and bone marrow revealed an EBV-positive diffuse large B-cell lymphoma with no recurrence of acute myeloid leukemia. His chemotherapy-induced immunosuppression likely predisposed him to develop this EBV-positive diffuse large B-cell lymphoma. This case highlights the need to consider a broader differential and immunohistochemical profiling of these neoplasms to avoid misdiagnosing complex oncology patients.

Sentinel lymph node biopsy for melanoma in pregnant women.

BACKGROUND: The incidence of melanoma is rising in young women of childbearing age. Melanoma diagnosed during pregnancy presents unique challenges. This study was conducted to determine the effect of sentinel lymph node biopsy (SLNB) for melanoma on maternal and fetal outcomes in pregnant women. METHODS: A prospective melanoma database was retrospectively queried for women diagnosed with melanoma during or immediately before pregnancy as well as SLNB in pregnant women. The outcomes of SLNB for the mothers and fetuses were evaluated. RESULTS: Fifteen pregnant women underwent wide local excision (WLE) and SLNB for melanoma from 1997 to 2012. The median gestational age was 20 weeks. More than half of the women noticed changes in the primary melanoma lesion during the pregnancy. The median Breslow thickness was 1.00 mm. Lymphatic mapping and SLNB were performed with some combination of radiocolloid or vital blue dye without adverse effects. Three patients had micrometastatic disease and underwent a completion lymphadenectomy. Sixteen children were born at a median gestational age of 39 weeks. The median 1- and 5-minute Apgar scores were 8 and 9, respectively. At a median follow-up of 54.4, months none of the patients had experienced recurrence, and all children were healthy and free of melanoma. CONCLUSIONS: In this series of pregnant women with melanoma, SLNB was performed safely during pregnancy without adverse effects to the mothers and fetuses. We recommend that clinicians explain the risks and benefits of the SLNB procedure to pregnant women so an informed decision can be made about the procedure.

Polarizable elements in scabies infestation: a clue to diagnosis.

The diagnosis of scabies infestation is straightforward in cases where mite parts are largely visible; however, mites are often not captured in a specimen's planes of section. Polariscopic examination is a fast and simple adjunctive diagnostic tool to light microscopy. We describe the unique polariscopic findings in scabies infestation. Two cases of crusted scabies and eight cases of typical scabies were subjected to polariscopic examination. Diagnostic mite parts were visualized in at least one section in all cases. Attached and detached spines as well as scybala (fecal material) are polarizable. Specifically, spines show a polarizable outer sheath with dark central core while scybala show peripherally concentrated, stippled birefringence. Similar stippled birefringence is visible within the gut of some mites whereas significant birefringence is not appreciated in other mite parts. These results suggest that polariscopic examination is a helpful clue in the diagnosis of scabies infestation, especially in cases where the body of the mite is not visualized.