High cutaneous amphiregulin expression predicts fatal acute graft-versus-host disease.

BACKGROUND: Amphiregulin (AREG) is increased in circulation in acute graft-versus-host disease (aGVHD) and is associated with poor steroid response and lower survival. The expression of AREG in aGVHD target organs and its association with clinical outcomes are unknown. METHODS: We performed AREG immunohistochemical staining on skin specimens from 67 patients with aGVHD between the years 2010 and 2015. Two blinded reviewers assessed AREG expression and scored specimens with a semiquantitative scale ranging from 0 (absent) to 4 (most intense). RESULTS: Median AREG score of aGVHD cases was 3. Sixteen of 67 (23.9%) aGVHD cases had an AREG >3. High skin AREG expression (>3 vs. ≤3) was associated with increased overall clinical grade of aGVHD (52.9% vs. 33.4% clinical grade III-IV, p = 0.02), reduced 3-year overall survival (OS; 13% vs. 61%, p < 0.01), and increased 3-year non-relapse mortality (NRM; 56% vs. 20%, p = 0.05). CONCLUSION: High skin AREG immunohistochemical expression is associated with high clinical grade aGVHD, poor OS, and increased NRM.

Intravascular pseudolymphomatous angiosarcoma: A new finding potentially mistaken for intravascular lymphoma.

Pseudolymphomatous infiltrates associated with angiosarcoma are a rarely reported phenomenon. Recognition of this reactive process is critical to making an accurate diagnosis, both in diagnosing the angiosarcoma and in avoiding an incorrect diagnosis of lymphoma. Here, we present a novel histopathologic pattern, angiosarcoma with a prominently intravascular atypical lymphoid component, mimicking intravascular T-cell lymphoma. Interestingly, serial biopsies in this case revealed a progressive increase in lymphocyte density and intravascular component over time. Despite prior reports of improved progression-free survival and overall survival of patients with pseudolymphomatous angiosarcoma, this patient showed rapid disease progression.

Concurrent mycosis fungoides and intravascular large B-cell lymphoma in a single patient.

Mycosis fungoides (MF) is an indolent, uncommon, non-Hodgkin T-cell lymphoma of the skin. It classically presents with patches, plaques, and tumors and may rarely show spread to internal organs or bone marrow. Up to 7.5% of MF patients may be diagnosed with a second malignancy. Intravascular large B-cell lymphoma (IVLBCL) is an exceedingly rare non-Hodgkin B-cell lymphoma characterized by predominant growth of large neoplastic cells in the lumina of blood vessels. This case presents with an unusual confluence of two rare diagnoses, MF and IVLBCL, made more remarkable by the presence of both diagnoses on a single skin biopsy sample.

Diffuse, mottled hyperpigmentation and mutations in LMNA gene in a 5-year-old boy, his mother, and his grandmother: Atypical progeroid syndrome.

We present a multigenerational family with a phenotypic spectrum of skin dyspigmentation, lipodystrophy, bony anomalies, and progeroid facies. All were found to be heterozygous for a c.11C>G (p.Pro4Arg) (P4R) mutation in the lamin A/C gene consistent with atypical progeroid syndrome. Various phenotypic associations have been reported with specific mutations in atypical progeroid syndrome, but the strength of each phenotype-genotype relationship is unknown. This report adds to the literature of patients with atypical progeroid syndrome and highlights an unusual diagnosis that may present to dermatologists.

Serum sickness-like drug reaction: two cases with a neutrophilic urticarial pattern.

The diagnosis of serum sickness-like reaction (SSLR) is typically based on clinical findings. Histopathologic examination is often deferred, as these eruptions commonly present in young children, and often to primary care providers. A PubMed literature search revealed only five existing cases of SSLR which describe cutaneous histopathologic features. We report two cases of SSLR, one each to bupropion and cefazolin. Skin biopsy findings in both cases showed a neutrophil-predominant urticarial pattern resembling neutrophilic urticaria or neutrophilic urticarial dermatosis. We also provide a summary of the histopathologic findings that can help support a diagnosis of SSLR.

Follicular Psoriasis: Differentiation from Pityriasis Rubra Pilaris-An Illustrative Case and Review of the Literature.

The follicular presentation of psoriasis is a well-described but uncommon variant. In some cases, follicular psoriasis may clinically and histopathologically mimic pityriasis rubra pilaris. There are several reports discussing the resemblance of widespread follicular psoriasis in children to pityriasis rubra pilaris. We describe a case of follicular psoriasis in a 16-year-old black girl with acrally distributed follicular hyperkeratotic papules with associated keratoderma of her plantar surfaces resembling pityriasis rubra pilaris.

The role of dermatopathology in inpatient care.

Skin biopsy remains one of the most important tools in the evaluation of dermatologic disease in hospitalized patients and is diagnostic for many common inpatient dermatoses, including various drug eruptions and cutaneous infections. The dermatopathology team thus plays a crucial role in the care of many of these patients and can add significant value through timely and precise diagnoses. Here, we review the unique challenges of dermatopathology in hospital-based medicine, discuss approaches to timely care, and examine effective clinicopathologic correlation in this setting.

Histopathology of vascular anomalies: update based on the revised 2014 ISSVA classification.

Precise diagnosis of childhood vascular anomalies is challenging, and requires careful correlation of clinical findings, diagnostic imaging, histopathology and genetic analysis. Skin and soft tissue biopsies remain an important element in the complete evaluation of many vascular anomalies included in the revised 2014 International Society for the Study of Vascular Anomalies (ISSVA) classification. Here we present an overview of the light microscopic and immunohistochemical features of the entities in this updated classification scheme, with emphasis on newly-included diagnoses such as PTEN hamartoma of soft tissue.

In the clinic. Common cutaneous parasites.

This issue provides a clinical overview of Common Cutaneous Parasites focusing on prevention, diagnosis, treatment, practice improvement, and patient information. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including ACP Smart Medicine and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of science writers and physician writers. Editorial consultants from ACP Smart Medicine and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://smartmedicine.acponline.org, http://mksap.acponline.org, and other resources referenced in each issue of In the Clinic.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome associated with neonatal epidermolysis bullosa acquisita.

We report the case of a 2-week-old boy who presented with a vesiculopustular, bullous eruption in the setting of autoimmune enteropathy, hypothyroidism, membranous nephropathy, Coombs-positive hemolytic anemia, and persistent eosinophilia. Immunologic testing revealed a deficiency of FOXP3-expressing regulatory T cells, and a diagnosis of immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome was made. Histologic analysis, immunofluorescence, and enzyme-linked immunosorbent assay confirmed the bullous eruption as epidermolysis bullosa acquisita with associated collagen VII autoantibody production. The skin lesions responded to systemic immunosuppressant therapy and have regressed after allogeneic bone marrow transplantation.

Cutaneous malignant melanoma: update on diagnostic and prognostic biomarkers.

The incidence of cutaneous malignant melanoma has rapidly increased in recent years in all parts of the world, and melanoma is a leading cause of cancer death. As even relatively small melanomas may have metastatic potential, accurate assessment of progression is critical. Although diagnosis of cutaneous malignant melanoma is usually based on histopathologic criteria, these criteria may at times be inadequate in differentiating melanoma from certain types of benign nevi. As for prognosis, tumor (Breslow) thickness, mitotic rate, and ulceration have been considered the most important prognostic indicators among histopathologic criteria. However, there are cases of thin primary melanomas that have ultimately developed metastases despite complete excision. Given this, an accurate assessment of melanoma progression is critical, and development of molecular biomarkers that identify high-risk melanoma in its early phase is urgently needed. Large-scale genomic profiling has identified considerable heterogeneity in melanoma and suggests subgrouping of tumors by patterns of gene expression and mutation will ultimately be essential to accurate staging. This subgrouping in turn may allow for more targeted therapy. In this review, we aim to provide an update on the most promising new biomarkers that may help in the identification and prognostication of melanoma.

PD-1 Inhibitor Induced Hypertrophic Lichen Planus: A Case Report.

BACKGROUND AND OBJECTIVE: PD-1 inhibitors have revolutionized cancer therapies and are being used to treat an expanding array of cancers. To best serve patients, clinicians should be familiar with the spectrum of skin manifestations associated with PD-1 inhibitor therapy. Here, we report a unique case of hypertrophic lichen planus (HLP) in a 64-year-old man treated with pembrolizumab; the presentation initially suggested a squamous cell carcinoma (SCC) morphology, then evolved into a morphology more typical of hypertrophic lichen planus. This case underscores the need for caution in diagnosing eruptive SCCs associated with PD-1 inhibitor therapy. In such instances, maintaining a high suspicion for lichenoid reactions as sequelae of PD-1 inhibitor treatment and starting an empiric trial of therapy for lichenoid dermatitis may be warranted to ensure timely management of lesions. METHODS: We describe a case of hypertrophic lichen planus mimicking squamous cell carcinoma in the setting of PD-1 inhibitory therapy with pembrolizumab. A PubMed literature review was conducted to identify other cases and determine the incidence of lichenoid reactions imitating squamous cell carcinoma in the setting of PD-1 inhibitor use. RESULTS: Our case is one of the few available pieces of literature describing eruptive hypertrophic lichen planus imitating SCC in the setting of PD-1 inhibitor use. Initial skin nodule biopsy appeared histologically compatible with squamous cell carcinoma. Repeat biopsy of the skin lesions revealed histological features consistent with hypertrophic lichen planus. Over time, lower extremity lesions evolved into a more typical appearance of hypertrophic lichen planus. Treatment with topical 0.05% clobetasol ointment and oral acitretin 25 mg led to complete resolution of lesions within 2-3 months. CONCLUSIONS: This case underscores the significance of maintaining vigilance for lichenoid reactions as potential sequelae of PD-1 inhibitor therapy. It highlights the variability in initial presentation and the potential for lesions to transform over time. Timely recognition and appropriate management, including high-potency topical corticosteroids and oral acitretin, are crucial for achieving favorable outcomes in patients experiencing such reactions. More studies are necessary to fully analyze the rate of HLP occurrence as a consequence of PD-1 inhibitor use.

Bullous tinea pedis with direct immunofluorescence positivity: when is a positive result not autoimmune bullous disease?

Skin biopsy for direct immunofluorescence (DIF) testing is an essential tool in the diagnosis of blistering diseases. In the majority of cases, positive epidermal immunofluorescent staining is indicative of an autoimmune bullous disease (AIBD). We identified 2 patients with bullous dermatophyte infection diagnosed on hematoxylin- and eosin-stained sections who had positive DIF findings on biopsy of perilesional skin. We subsequently reviewed the literature regarding positive DIF findings in conditions other than AIBD. Other infections, including herpesviridae, scabies, and orf, have rarely been reported to yield positive DIF findings, with positive staining at the dermoepidermal junction. Some genodermatoses and many inflammatory skin diseases, including lichen planus, psoriasis, graft-versus-host disease, among others, may also have DIF findings mimicking those of both intra- and subepidermal AIBD. Although rare, positive DIF results occur in conditions other than AIBD. In many instances, the pathophysiological mechanisms behind immunoreactant deposition in these conditions are poorly understood. Misleading DIF results may lead to delay in correct diagnosis and treatment. Clinicians should be aware of potential alternate sources of positivity when there is lack of clinical correlation with immunofluorescence findings.

Mixed versus pure variants of desmoplastic melanoma: a genetic and immunohistochemical appraisal.

Desmoplastic melanoma is subclassified into pure and mixed variants with a higher rate of lymph node metastasis in the latter. Given that reasons for these biological differences are not currently known, we investigated these subtypes with techniques that included genetic and immunohistochemical analyses of 43 cases of desmoplastic melanoma (24 pure, 19 mixed). Direct DNA sequencing was performed on BRAFV600E, RET gene (coding region on exon 11) and KIT (exons 11, 13 and 17). Immunohistochemical stains were performed with antibodies to markers of significance with respect to biological potential of nevomelanocytic proliferations and/or desmoplastic melanoma (Ki-67, CD117, nestin, clusterin, SOX10 and CD271/p75NTR). Polymorphism at the RET coding region (RETp) was noted in 33% of pure (8/24 cases) versus 24% of mixed (4/17 cases); BRAFV600E was absent in all cases of pure (0/24 cases) versus 6% of mixed (1/17 cases); no mutations were found in any of the cases on analyses of exons 11, 13 and 17 of the c-KIT gene (P=NS for all). For immunohistochemical analyses of pure versus mixed: mean percentage of Ki-67 nuclear positivity was 5% (s.d.=5.6) versus 28% (s.d.=12.6, P<0.001); CD117 stained 26% (6/23 cases) versus 78% (14/18 cases, P<0.01); nestin stained 83% (n=19/23 cases) versus 89% (16/18 cases, P=NS); clusterin stained 4% (1/23 cases) versus 6% (1/18 cases, P=NS); SOX10 87% (20/23 cases) versus 94% (17/18 cases, P=NS) and CD271 stained 61% (14/23 cases) versus 67% (12/18 cases, P=NS). Increased CD117 staining in the mixed variant suggests that alterations in the KIT protein may be involved in tumor progression. In addition, the proliferative index of the mixed variant was higher than that of the pure variant.

Reactive granular histiocytosis secondary to arthroplasty prosthesis: a novel reaction pattern.

A reactive histiocytic infiltrate can be seen as an incidental finding in a lymph node biopsy from a patient with a history of joint arthroplasty. We report the case of a 74-year-old female who underwent surgical revision of a polyethylene-based right total knee prosthesis due to chronic wear. At the time of surgery, a soft tissue mass adjacent to the tibial prosthetic insert was noted and excised. Histopathologic examination revealed a sheet-like proliferation of large, histiocytoid cells within the subcutis and superficial fascia. The cells showed abundant eosinophilic, granular cytoplasm and small round bland nuclei. Immunohistochemical evaluation revealed the cells to be positive only for CD68. In addition, abundant PAS-positive cytoplasmic granules were found, and minute particles of polarizable material were noted intracellularly and scattered throughout the interstitium of the infiltrate. These findings were interpreted as consistent with a reactive, non-Langerhans cell histiocytosis secondary to the patient's polyethylene knee prosthesis. This finding appears to be a local correlate of the process previously described in regional lymph nodes as reactive granular histiocytosis. Dermatopathologists should be cognizant of this uncommon reaction pattern to avoid mistaking it for a neoplastic process.

Acute New World cutaneous leishmaniasis presenting as tuberculoid granulomatous dermatitis.

Acute primary cutaneous leishmaniasis typically presents microscopically with a lymphohistiocytic infiltrate containing admixed plasma cells, parasitized macrophages and abundant organisms. Tuberculoid granulomatous changes may occur in the later phases of primary infection. A 23-year-old male presented 1 month after visiting Peru with classic clinical findings of acute primary cutaneous leishmaniasis, while histopathology showed a tuberculoid granulomatous process that lacked any organisms in hematoxylin-eosin and fungal stains. Polymerase chain reaction (PCR) analysis and tissue cultures confirmed the diagnosis of cutaneous leishmaniasis with Leishmania (Viannia) panamensis infection. A pauci-organism tuberculoid granulomatous process may uncommonly be the presenting histopathology in the acute infectious phase of cutaneous leishmaniasis. Clinicians and dermatopathologists should be aware of this atypical presentation, which may cause diagnostic confusion and delay proper treatment. PCR testing should be employed in cases with high clinical suspicion when histopathology is not definitive.

Levamisole-induced vasculopathy: a report of 2 cases and a novel histopathologic finding.

Although cocaine-induced pseudovasculitis and urticarial vasculitis have been reported in the past, levamisole-induced vasculopathy with ecchymosis and necrosis, termed here LIVEN, has only recently been described in association with cocaine use. Levamisole, a veterinary antihelminthic agent used previously as an immunomodulating agent, is present as a "cutting agent" in approximately two-thirds of the cocaine currently entering the United States. Levamisole is believed to potentiate the effects of cocaine and may also be used as a "signature" for tracing its market distribution. Herein, we report 2 cases of LIVEN in patients with histories of chronic cocaine use. In both the cases, a temporal association with neutropenia preceding the eruption was noted. A novel histopathologic finding present only in the second case was the presence of extensive interstitial and perivascular neovascularization. Our 2 cases reaffirm that neutropenia may precede the cutaneous eruption of LIVEN. Case 2 extends the spectrum of histopathologic findings to include the novel phenomenon of neovascularization-hitherto unreported in this entity.