Multimodal single-cell analysis of cutaneous T-cell lymphoma reveals distinct subclonal tissue-dependent signatures.

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of mature T-cell neoplasms characterized by the accumulation of clonal malignant CD4+ T cells in the skin. The most common variant of CTCL, mycosis fungoides (MF ), is confined to the skin in early stages but can be accompanied by extracutaneous dissemination of malignant T cells to the blood and lymph nodes in advanced stages of disease. Sézary syndrome (SS), a leukemic form of disease, is characterized by significant blood involvement. Little is known about the transcriptional and genomic relationship between skin- and blood-residing malignant T cells in CTCL. To identify and interrogate malignant clones in matched skin and blood from patients with leukemic MF and SS, we combine T-cell receptor clonotyping with quantification of gene expression and cell surface markers at the single cell level. Our data reveal clonal evolution at a transcriptional and genetic level within the malignant populations of individual patients. We highlight highly consistent transcriptional signatures delineating skin- and blood-derived malignant T cells. Analysis of these 2 populations suggests that environmental cues, along with genetic aberrations, contribute to transcriptional profiles of malignant T cells. Our findings indicate that the skin microenvironment in CTCL promotes a transcriptional response supporting rapid malignant expansion, as opposed to the quiescent state observed in the blood, potentially influencing efficacy of therapies. These results provide insight into tissue-specific characteristics of cancerous cells and underscore the need to address the patients' individual malignant profiles at the time of therapy to eliminate all subclones.

Lymphomatoid papulosis.

Lymphomatoid papulosis is often regarded as a low-grade variant of cutaneous T cell lymphoma (CTCL). Given the excellent long-term prognosis, recent consensus guidelines indicate that patients can be monitored off therapy. We report a case of a 67-year-old man who presented with lymphomatoid papulosis, with necrotic papules that have been intermittently present for over forty years.

The Department of Defense: pioneers of early teledermatology.

The United States (US) Department of Defense(DoD) has been a leader in using telecommunicationstechnology to provide remote medical care. The DoDhas been using telemedicine for more than twentyyears to provide medical services to military personneldeployed throughout the world, and has largelyinfluenced the development of teledermatology. Theexperiences of early military teledermatology serviceshave yielded valuable lessons that have been essentialto the creation of successful civilian programs.

Kaposi's sarcoma in an HIV-negative patient.

We report an HIV-negative, 55-year-old manwith recurrent Kaposi's sarcoma (KS) of the lowerextremities, who does not fit into any of thefour previously described variants of KS: classicKS, AIDS-related KS, iatrogenic KS, and AfricanendemicKS. There are reports in the literature ofchildhood-onset KS, which is thought to be dueto an inherited immune deficiency that confers ahigher susceptibility to human Herpesvirus-8 (HHV-8), which is the virus that is known to cause KS. Ourpatient may be affected with an inherited immunedeficiency that has predisposed him to KS, and thismutation also may account for his prostate andbladder cancer.

Primary cutaneous marginal-zone lymphoma.

Primary cutaneous B cell lymphomas (PCBCL) are thesecond most common type of primary cutaneouslymphoma. The three main types of PCBCL areprimary cutaneous marginal-zone lymphoma(PCMZL), primary cutaneous follicle-centerlymphoma, and primary cutaneous diffuse largeB-cell lymphoma, leg type. PCMZL has an indolentcourse with a five-year survival rate approaching99%. Lesions most often present on the trunk or armas erythematous-to-violaceous papules, plaques, ornodules. Approximately one-half of patients havesolitary skin lesions. Treatment options includesurgery, radiation, and topical, intralesional orsystemic therapy. We present the case of a 33-yearoldHispanic woman with firm, pruritic, pink papuleson the forehead and cheeks, who was diagnosedwith PCMZL.

Mycosis fungoides with epidermal mucinosis: a variant of mycosis fungoides with a spongiosis-like pattern.

BACKGROUND: The histopathologic diagnosis of mycosis fungoides (MF) has classically relied on the presence of atypical epidermotropic T-lymphocytes predominating over spongiosis. However, in some cases of MF, prominent epidermal mucinosis in a spongiosis-like pattern mimics a spongiotic dermatitis. To our knowledge, only one series in the literature has thus far recognized the presence of epidermal mucinosis in MF. METHODS: We evaluated 30 skin biopsies from 18 patients with the clinical diagnosis of MF, which fulfilled all histopathologic criteria for patch- or plaque-stage MF, but also showed epidermal mucinosis in a spongiosis-like pattern. A total of 15 specimens were studied by immunohistochemistry, and seven were tested for T-cell receptor (TCR) gene rearrangements. Twenty biopsies of spongiotic dermatitides were included as controls. RESULTS: We confirmed the presence of epidermal mucinosis in all 30 cases of MF with a spongiosis-like pattern based on histopathologic criteria and the colloidal iron stain for mucin. Immunohistochemistry in 15 specimens showed significant loss of pan-T-cell antigens CD5 (10/15) and CD7 (14/15); and TCR clonality was detected in 7 specimens from 6 patients, supporting the diagnosis of MF. CONCLUSIONS: We report helpful histopathologic criteria for distinguishing MF with epidermal mucinosis in a spongiosis-like pattern from spongiotic dermatitis.

A variant of palpable migratory arciform erythema.

Palpable migratory arciform erythema is a T-cell pseudolymphoma with no well-established treatment. The disease is rarely reported in the literature, perhaps because it is difficult to diagnose. We present a case of a variant of PMAE in a 30-year-old healthy man with no history of medication use and erythematous to violaceous annular and arciform plaques on his face, scalp and trunk. This case is of particular significance because gene rearrangement studies and histopathologic findings are concerning for folliculotropic mycosis fungoides while the clinical course does not support this diagnosis. The authors' emphasize that clinical history is imperative for definitive diagnosis of palpable migratory arciform erythema as it can clinically and histopathologically resemble other cutaneous lymphocytic diseases.

Primary cutaneous follicle-center lymphoma.

We present a 64-year-old man with a three-year history of pruritic, pink papules and nodules of the face who was found to have a clonal lymphoproliferative B-cell disease that was characterized by a clonal IGH rearrangement. Although morphologic features present in the biopsy specimen were consistent with a reactive process, additional clinicopathologic correlation (anatomic presentation of lesions on the face, the absence of t(14:18) translocation, and bcl-2 and MUM1 expression) reinforced suspicion of a cutaneous B-cell lymphoma. Systemic work-up with CT/PET and a bone marrow biopsy ultimately excluded systemic disease and primary cutaneous follicle-center lymphoma (PCFCL) was a strong diagnostic consideration. The patient was treated with systemic rituximab with a partial resolution of the facial lesions. The case demonstrates both clinical and pathologic challenges to the diagnosis of primary cutaneous B-cell lymphoma (PCBCL). Furthermore, despite a newly refined classification system, the case also specifically highlights the persistent requirement for flexible clinical reasoning and pathologic correlation. Such reasoning is necessary to generate individualized strategies for diagnosis and treatment when cutaneous B-cell lymphoma is suspected.

Predictors for the use of systemic therapy in stage IB Mycosis fungoides.

BACKGROUND: The PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) study is aprospective analysis of an international database. Here we examine front-line treatments and quality of life (QoL) inpatients with newly diagnosed mycosis fungoides (MF). OBJECTIVES: To identify (i) differences in first-line approaches according to tumour-nodes-metastasis-blood (TNMB)staging; (ii) parameters related to a first-line systemic approach and (iii) response rates and QoL measures. METHODS: In total, 395 newly diagnosed patients with early-stage MF (stage IA-IIA) were recruited from 41 centresin 17 countries between 1 January 2015 and 31 December 2018 following central clinicopathological review. RESULTS: The most common first-line therapy was skin-directed therapy (SDT) (322 cases, 81·5%), while a smallerpercentage (44 cases, 11·1%) received systemic therapy. Expectant observation was used in 7·3%. In univariateanalysis, the use of systemic therapy was significantly associated with higher clinical stage (IA, 6%; IB, 14%; IIA,20%; IA-IB vs. IIA, P < 0·001), presence of plaques (T1a/T2a, 5%; T1b/T2b, 17%; P < 0·001), higher modified Severity Weighted Assessment Tool (> 10, 15%; ≤ 10, 7%; P = 0·01) and folliculotropic MF (FMF) (24% vs. 12%, P = 0·001). Multivariate analysis demonstrated significant associations with the presence of plaques (T1b/T2b vs.T1a/T2a, odds ratio 3·07) and FMF (odds ratio 2·83). The overall response rate (ORR) to first-line SDT was 73%,while the ORR to first-line systemic treatments was lower (57%) (P = 0·027). Health-related QoL improvedsignificantly both in patients with responsive disease and in those with stable disease. CONCLUSIONS: Disease characteristics such as presence of plaques and FMF influence physician treatment choices,and SDT was superior to systemic therapy even in patients with such disease characteristics. Consequently, futuretreatment guidelines for early-stage MF need to address these issues.

Graft-vs-host disease.

We present a case of chronic graft-versus-host disease in a 61-year-old woman with a history of B-cell chronic lymphocytic leukemia that was treated with an allogeneic bone marrow transplant from an unrelated donor. The patient initially presented with erythematous patches on the trunk and extremities that evolved into reticulated, hyperpigmented patches and lichenified plaques.

Lichen sclerosus et atrophicus.

Morphea and lichen sclerosus et atrophicus (LSA) have similar clinical presentations. Reports of patients with overlapping clinical and histopathologic features of both conditions have led some to speculate that they may represent different presentations along the same disease spectrum. It has been postulated that there is a common etiologic agent, which may involve autoimmunity, response to trauma, or infection. The link between Borrelia infection and both morphea and LSA has been widely studied but remains controversial. We present a case of a patient with lesions characterized by overlapping features of morphea and LSA with rapid decrease in joint mobility.

Muckle-Wells treatment with anakinra.

A 35-year-old man initially was referred for management of recalcitrant urticaria. Owing to his long history of arthritis and sensorineural hearing loss, genetic testing was performed. The test showed a D305N heterozygous mutation in the NLRP3 gene, which is consistent with the diagnosis of Muckle-Wells syndrome. We discussed the rationales behind the use of the interleukin-1 antagonist anakinra in this autoinflammatory disorder.

Digitate dermatosis (small-plaque parapsoriasis).

We report a 79-year-old man with a 15-year history of elongated, finger-like, erythematous patches that are symmetrically distributed on his flanks and of small, <5 cm, erythematous, slightly scaly, round-oval patches on the upper and lower extremities. The lesions were occasionally pruritic and waxed and waned over the years. His clinical and histopathologic data indicated small-plaque parapsoriasis, which is a benign entity that has been the center of controversy over the years, owing to its similarities to large-plaque parapsoriasis, which is on a spectrum with mycosis fungoides.

Necrobiotic xanthogranuloma.

Necrobiotic xanthogranuloma (NXG) is a rare, chronic, progressive, non-Langerhans histiocytosis that is strongly associated with hematologic malignant conditions. Only about 100 cases have been reported in the literature since it was first described in 1980. It is important for dermatologists to recognize NXG and initiate a prompt hematologic evaluation. IgG kappa is the most frequently discovered monoclonal gammopathy (65%), followed by IgG lambda (35%), and, much less commonly, IgA. Although no modality has been shown to be consistently effective, therapeutic options include glucocorticoids (topical, intralesional, and/or systemic), alkylating agents (chlorambucil and cyclophosphamide). interferon alpha, antimetabolites, antibiotics, thalidomide, and plasmaphersis.

Verrucous and macular sarcoidosis.

We present a case of cutaneous sarcoidosis in a 77-year-old woman without systemic disease, who presented with two subtypes of lesions: erythematous and hyperpigmented macules on the arms and anterior upper legs and erythematous, hyperkeratotic nodules, some crateriform, on the lower legs and feet. Whereas cutaneous sarcoidosis is present in up to one-third of cases and may present with a wide variety of lesions, verrucous sarcoidosis is uncommon. Diagnosis is by clinical and histopathologic exclusion of other entities, which include other causes of granulomatous inflammation such as infections and foreign-body reactions. Management options include topical, intralesional, or systemic glucocorticoids, antimalarials, tetracycline derivatives, and methotrexate.

Linear morphea of the forehead (en coup de sabre).

Linear morphea of the forehead or en coup de sabre (ECDS) is an unusual variant of morphea. It typically occurs in children although cases of adult-onset ECDS exist as reported here. ECDS has a specific distribution on the frontal scalp and forehead and is usually unilateral. Sclerosis in ECDS lesions may invade deeply to involve underlying muscle and bone and may exist on the same clinicopathologic spectrum as Parry-Romberg syndrome. Extracutaneous involvement is frequent, with neurologic and ophthalmologic findings occurring most commonly. The etiology of ECDS is unclear but may be autoimmune in origin. The question of whether Borrelia infection also plays a role remains controversial. Current evidence supports first-line treatment with methotrexate and oral glucocorticoids followed by phototherapy and mycophenolate mofetil.

Poikilodermatous mycosis fungoides.

Poikilodermatous mycosis fungoides (MF) is a variant of MF, formerly referred to as poikiloderma vasculare atrophicans. The lesions are classically characterized by large plaques of hypopigmentation and hyperpigmentation with atrophy and telangiectases. The plaques may be asymptomatic or mildly pruritic and typically involve the major flexural areas and trunk. Poikilodermatous MF has an early stage (IA-IIA) at diagnosis and a male predominance. Poikilodermatous MF shows an atypical T-cell infiltrate in the papillary dermis with evidence of epidermotropism, epidermal atrophy, dilated blood vessels in the dermis, melanophages, and melanin incontinence. Recent studies suggest a predominance of a CD8+, CD4- immunophenotype. Treatment modalities are similar to classic MF with phototherapy being the most common first-line therapy. Poikilodermatous MF has an excellent prognosis.

Diffuse large B-cell lymphoma.

We present a 56-year-old man with a two-year history of erythematous nodules and plaques on the forehead, frontal aspect of the scalp, and left side of the neck. Histopathologic findings are compatible with a diagnosis of diffuse large B-cell lymphoma (DLBCL). We present a brief review of primary cutaneous DLBCLs and address the putative association between DLBCLs and hepatitis C virus infection.

Diversifying the dermatology workforce: Physician characteristics vary by race/ethnicity.

BACKGROUND: In the United States (US), dermatology remains one of the least diverse specialties in medicine. Increasing the diversity of the dermatology workforce is essential for reducing health disparities. OBJECTIVE: To describe the experiences of racially and ethnically diverse physicians in the US who successfully matched into dermatology. METHODS: Board-certified dermatologists and dermatology residents were recruited to participate in an anonymous, online survey in which self-reported demographic, socioeconomic, pre-residency, and post-residency career data were obtained. RESULTS: Of the 100 participants included in the study, 30% were dermatology residents and 25% belonged to a group underrepresented in medicine (UIM). Black physicians were 3.69 times more likely to select dermatology prior to medical school (odds ratio [OR], 3.69; 95% confidence interval [CI], 1.04 - 13.0) compared to non-Black physicians. UIM dermatologists and trainees were more likely to receive a need-based scholarship in medical school (OR, 4.37; 95% CI, 1.30 - 14.7), graduate from a private medical institution (OR, 6.49; 95% CI, 1.95 - 21.6), and have at least one UIM dermatology mentor during medical school (adjusted OR, 13.1; 95% CI, 2.77 - 61.5) compared to non-UIM physicians. CONCLUSIONS: A holistic review of dermatology applicants by residency programs may reduce racial/ethnic disparities in the admission process. Our data provide further evidence in support of pre-medical outreach programs, mentorship, and institutional funding to promote diversity in dermatology.