Reactive granulomatous dermatitis as a histological pattern including manifestations of interstitial granulomatous dermatitis and palisaded neutrophilic and granulomatous dermatitis: a study of 52 patients

BACKGROUND

Confusion exists regarding interstitial granulomatous dermatitis (IGD) and palisaded neutrophilic and granulomatous dermatitis (PNGD).

OBJECTIVE

To determine whether IGD and PNGD are two different entities, or whether they must be considered as two subtypes of the same reactive pattern, and thus whether the unification of the nomenclature is necessary.

METHODS

Observational retrospective multicentre study of patients with IGD and PNGD evaluated between 1999 and 2019 and review of their clinical and histological features.

RESULTS

We identified 52 patients (38 women and 14 men). Clinical and histological findings of IGD were observed in 88.4% of cases. The most common cutaneous lesions were plaques/macules (IGD) or annular plaques and papules/nodules (PNGD), located mostly on the limbs and trunk. The rope sign was developed in two patients with IGD that associated autoimmune disorders. Similar associated comorbidities (75%) were found in both entities, mainly autoimmune diseases (53.8%). In IGD, the infiltrate was predominantly lympho-histiocytic. Neutrophilic infiltrates, karyorrhexis and skin lesions with limited clinical course were mainly associated with PNGD biopsies. In biopsies with a limited recurrent course, a predominant lymphocytic inflammatory infiltrate was found. Collagen degeneration was present in 75.9% of cases. The floating sign was observed only in IGD type patients (63%). Overlapping histological findings were found in one fourth of cases, especially between IGD and interstitial granuloma annulare. Interface dermatitis, apparently unrelated to drug intake, was observed in 4 cases of IGD.

CONCLUSION

We support the term reactive granulomatous dermatitis to unify both the clinical and histological findings of IGD and PNGD, and the overlapping between IGD and interstitial granuloma annulare. According to this, a spectrum of histological changes will be found depending on the clinical course of the skin lesions.

Analysis of mismatch repair (MMR) proteins expression in a series of malignant pleural mesothelioma (MPM) patients

BACKGROUND

Promising results have been reported with immune checkpoint inhibitors (ICI) in a small proportion of MPM patients. MMR deficiency (dMMR) has been well described in several malignancies and was approved as a biomarker for anti-PD-1 inhibitors. Next generation sequencing (NGS) data demonstrated that 2% of MPM harbor microsatellite instability. The aim of this study is to characterize MMR by immunohistochemistry (IHC) in a series of MPM including a subset of patients treated with immunotherapy.

METHODS

Tumors of 159 MPM p diagnosed between 2002 and 2017 were reviewed. Formalin-fixed, paraffin-embedded tissue was stained for MLH1, MSH2, MSH6 and PMS2 and tumors were classified as dMMR (MMR protein expression negative) and MMR intact (all MMR proteins positively expressed). We retrospectively collected clinical outcomes under standard chemotherapy and experimental immunotherapy in the entire cohort.

RESULTS

MMR protein expression was analyzed in 158 samples with enough tissue and was positive in all of the cases. Twenty two patients received ICI with anti-CTLA4 or anti-PD-1 blockade in clinical trials, 58% had a response or stable disease for more than 6 m, with median progression-free survival (PFS) of 5.7 m (2.1-26.1 m). The median overall survival (mOS) in all population was 15 months (m) (13.5-18.8 m). In a multivariable model factors associated to improved mOS were PS 0, neutrophil-lymphocyte ratio (NLR) < 5 and epithelioid histology (p < 0.001).

CONCLUSIONS

In our series we were unable to identify any MPM patient with dMMR by IHC. Further studies are needed to elucidate potential predictive biomarkers of ICI benefit in MPM.

Clinical utility of plasma-based digital next-generation sequencing in patients with advance-stage lung adenocarcinomas with insufficient tumor samples for tissue genotyping

BACKGROUND

Approximately 30% of tumor biopsies from patients with advanced-stage lung adenocarcinomas yield insufficient tissue for successful molecular subtyping. We have analyzed the clinical utility of next-generation sequencing (NGS) of cell-free circulating tumor DNA (ctDNA) in patients with inadequate tumor samples for tissue genotyping.

PATIENTS AND METHODS

We conducted the study in a multi-institutional prospective cohort of clinically unselected patients with advanced-stage lung adenocarcinomas with insufficient tissue for EGFR, ALK or ROS1 genotyping across 12 Spanish institutions (n = 93). ctDNA NGS was carried out by Guardant Health (Guardant360, Redwood City, CA), using a hybrid-capture-based 73-gene panel. Variants were deemed actionable if they were part of the OncoKB precision oncology knowledge database and classified in four levels of actionability based on their clinical or preclinical evidence for drug response.

RESULTS

Eighty-three out of 93 patients (89%) had detectable levels of ctDNA. Potentially actionable level 1-4 genomic alterations were detected in 53 cases (57%), of which 13 (14%) had level 1-2A alterations (Food and Drug Administration-approved and standard-care biomarkers according to lung cancer guidelines). Frequencies of each genomic alteration in ctDNA were consistent with those observed in unselected pulmonary adenocarcinomas. The majority of the patients (62%), particularly those with actionable alterations (87%), had more than one pathogenic variant in ctDNA. The median turnaround time to genomic results was 13 days. Twelve patients (13%) received genotype-matched therapies based on ctDNA results, deriving the expected clinical benefit. Patients with co-occurring pathogenic alterations had a significantly shorter median overall survival as compared with patients without co-occurring pathogenic alteration (multivariate hazard ratio = 5.35, P = 0.01).

CONCLUSION

Digital NGS of ctDNA in lung cancers with insufficient tumor samples for tissue sequencing detects actionable variants that frequently co-occur with other potentially clinically relevant genomic alterations, allowing timely initiation of genotype-matched therapies.

International Bullous Diseases Group: consensus on diagnostic criteria for epidermolysis bullosa acquisita

BACKGROUND

Epidermolysis bullosa acquisita (EBA) is a complex autoimmune bullous disease disease with variable clinical presentations and multiple possible diagnostic tests, making an international consensus on the diagnosis of EBA essential.

OBJECTIVES

To obtain an international consensus on the clinical and diagnostic criteria for EBA.

METHODS

The International Bullous Diseases Group (IBDG) met three times to discuss the clinical and diagnostic criteria for EBA. For the final voting exercise, 22 experts from 14 different countries voted on 50 different items. When > 30% disagreed with a proposal, a discussion was held and re-voting carried out.

RESULTS

In total, 48 of 50 proposals achieved consensus after discussion. This included nine diagnostic criteria, which are summarized in a flow chart. The IBDG was unable to determine one procedure that would be applicable worldwide. A limitation of the study is that differential diagnosis of bullous systemic lupus erythematosus has not been addressed.

CONCLUSIONS

This first international consensus conference established generally agreed-upon clinical and laboratory criteria defining the clinical classification of and diagnostic testing for EBA. Holding these voting exercises in person with the possibility of discussion prior to voting has advantages in reaching consensus over Delphi exercises with remote voting.

Retrospective study of the clinical, histologic, and immunologic features of epidermolysis bullosa acquisita in 9 patients

INTRODUCTION

Epidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease caused by autoantibodies to type VII collagen. The clinical presentation is variable, with skin and mucosal lesions that can cause significant dysfunction. Different treatment options exist, but the results are often unsatisfactory.

OBJECTIVE

To review all the cases of epidermolysis bullosa acquisita (EBA) diagnosed at our hospital over a 26-year period.

MATERIALS AND METHODS

We performed a retrospective review of the clinical, histologic, and immunologic features of EBA in 9 patients.

RESULTS

Mean age at presentation was 37 years and 66.67% of the patients were women. EBA occurred in association with malignant tumors, inflammatory bowel disease, and autoimmune disorders. The most common variant was inflammatory EBA (6 of the 9 cases). In all 9 patients, histology revealed a subepidermal blister and direct immunofluorescence showed linear deposits of immunoglobulin G and C3 in the basement membrane zone. Indirect immunofluorescence performed on salt-split skin substrate was positive in 6 patients and showed a dermal pattern in all cases. Five patients were tested for autoantibodies to type VII collagen using enzyme-linked immunosorbent assay, with positive results in 2 cases. Immunoblotting using recombinant noncollagenous domains (NC1) of type VII collagen was positive in all 6 cases in which it was performed. Response to treatment was variable.

CONCLUSIONS

EBA is a rare disease with a variable clinical presentation that can be confused with that of other subepidermal blistering diseases. Correct diagnosis requires a high level of clinical suspicion and the use of all available diagnostic tests. Thorough evaluation of cutaneous and mucosal involvement and prompt initiation of appropriate treatment will ensure the detection and prevention of dysfunction and treatment-related complications.

Treatment of bullous pemphigoid with low-dose oral cyclophosphamide: a case series of 20 patients

BACKGROUND

Cyclophosphamide has been commonly used for the treatment of pemphigus vulgaris and mucous membrane pemphigoid with satisfactory results. Published data of this therapeutic approach for bullous pemphigoid are scant and showed significant morbidity and mortality.

OBJECTIVE

To assess the clinical efficacy and safety of low-dose oral cyclophosphamide (CFM) (50-100 mg/day) in patients with refractory bullous pemphigoid.

METHODS

We conducted a retrospective study including patients with bullous pemphigoid treated with CFM in the department of Dermatology in the Hospital Clínic of Barcelona, Spain.

RESULTS

Complete response was observed in 11 (58%) over 19 evaluable patients. Cyclophosphamide at 50 mg/day was enough to achieve clinical remission in eight of these patients. Partial response was observed in four (21%) more patients. Bone marrow suppression appeared in 12 (60%) patients, but treatment discontinuation was only required in three (15%) cases. Gastrointestinal intolerance occurred in one (5%) patient. One patient died during therapy from heart failure (not attributed to CFM) and another patient developed acute myeloid leukaemia 1.5 years after CFM therapy.

CONCLUSIONS

In our series, CFM had a marked therapeutic effect in bullous pemphigoid. These results of efficacy are similar to those described in other autoimmune blistering skin diseases. Only a few patients had to discontinue their treatment due to adverse effects. Therefore, we consider that low-dose oral CFM can be valuable therapeutic alternative in elderly patients with moderate-to-severe bullous pemphigoid.

[Annular plaques in the skin folds: 4 cases of lichen planus pigmentosus-inversus]

We report 4 patients with relatively asymptomatic, annular brownish plaques arising in the skin creases.The lesions had remained stable for months despite many topical treatments. Histological examination revealed an atrophic epidermis with a dermal lichenoid inflammatory infiltrate showing marked pigmentary incontinence.These clinical and pathological features were consistent with lichen planus pigmentosus-inversus,a rare, recently described variant of lichen planus, with only 10 cases reported to date. It has been suggested that he intensity and speed of onset of the inflammatory response could be modulated by keratinocyte surface markers, which could also determine the typical morphology of the lesions of this disease.