[Lichenoid drug eruption with unfavorable evolution. Difficulties in diagnosis]. / Erupción liquenoide medicamentosa con evolución desfavorable. Dificultades en el diagnóstico.

We report the case of a woman who started with a lichenoid eruption, unfavorable evolution, for which a drug reaction was suspected. The final diagnosis was paraneoplastic pemphigus. Multidisciplinary care and evaluation by an Allergist is important in patients with severe skin reactions, suspected of drug reactions, due to the difficulty in establishing the diagnosis.

Se reporta el caso de una mujer que inició con erupción liquenoide, con evolución desfavorable, por lo que se sospechó una reacción medicamentosa. El diagnóstico final fue pénfigo paraneoplásico. Es importante la atención multidisciplinaria y la evaluación de un alergólogo en pacientes con reacciones cutáneas graves, por sospecha de reacciones farmacológicas, debido a la dificultad para establecer el diagnóstico.

Clinical and epidemiological profile of lichen striatus in children-Experience from a tertiary care hospital.

We analyzed records of 30 patients with lichen striatus (age < 18 years) in this retrospective study. Seventy percent were females and 30% were males with a mean age of diagnosis of 5.38 ± 4.22 years. The most common age group affected was 0-4 years. The mean duration of lichen striatus was 6.66 ± 4.22 months. Atopy was present in 9 (30%) patients. Although LS is a benign self-limited dermatosis, long-term prospective studies with a greater number of patients will help in better understanding of the disease including its etiopathogenesis and association with atopy.

Annular Lichenoid Dermatitis of Youth: Its Pathogenesis, Diagnosis, and Management.

Annular lichenoid dermatitis of youth (ALDY) is a newly described controversial benign lichenoid inflammatory cutaneous disorder often characterized by annular patches with hypopigmented center and surrounding erythematous border. Primarily, it affects the trunk and groin of young patients. Since its first description in 2003, additional patients have been reported, leading to better characterization of the entity; nevertheless, the pathogenesis is still unclear, and several hypotheses have been provided about possible triggering or causative factors. It tends to follow a chronic course, with some lesions spontaneously remitting, while others may be persistent or recur post-treatment. No standard validated treatment has been indicated so far for this disorder. Commonly prescribed topical treatment includes corticosteroids and calcineurin inhibitors with variable response.

PRAME immunohistochemistry can distinguish melanocytic pseudonests of lichenoid reactions from melanoma in situ.

BACKGROUND: Distinguishing melanocytic pseudonests encountered in lichenoid dermatoses or lichenoid keratoses from melanoma in situ (MIS) with brisk lichenoid inflammation can prove challenging. METHODS: We designed a case-control study to evaluate the accuracy metrics of PRAME immunohistochemistry to distinguish melanocytic pseudonests in lichenoid dermatoses or keratoses from inflamed MIS. Immunostaining for PRAME was performed on paraffin-embedded formalin-fixed diagnostic tissue using a rabbit monoclonal antibody to PRAME (Abcam), with a 1:3200 dilution on a Leica Bond detection system. RESULTS: Our search identified 21 cases of melanocytic pseudonests (n = 21, 46%) encountered in lichenoid dermatoses and 24 cases of inflamed MIS (n = 24, 53%). Each method of evaluating PRAME immunohistochemistry (PRAME+ clusters, PRAME % of melanocytes by four categories and PRAME+ melanocyte counts per linear mm of epidermal basal layer) showed statistically significant differences between the MIS and the pseudonest cohorts (respectively, p < 0.001; p < 0.001; and p < 0.001). Receiver operating characteristics analysis for PRAME+ melanocyte counts per linear mm of epidermal basal layer revealed an area under the curve of 0.9 ± 0.05 (95% confidence interval 0.9-1.0). When determining an optimal cut-off point for the best Youden index [sensitivity (%) + specificity (%) - 100], the cut-off of 1.0 PRAME+ melanocytes per linear mm showed a sensitivity of 79.2% and specificity of 85.7% (Youden index 0.65) to distinguish MIS from pseudonests. CONCLUSION: PRAME immunohistochemistry may constitute an additional tool for this challenging differential diagnosis.

Lichenoid drug eruption associated with imatinib mesylate therapy.

INTRODUCTION: Imatinib Mesylate (IM), a tyrosine kinase inhibitor, has been reported to cause several adverse reactions, most of them with cutaneous involvement. Non- Lichenoid IM associated skin reactions have been sufficiently- recorded. To our knowledge, Lichenoid Drug Eruption (LDE) is recorded in a minority of registries. CASE REPORT: To describe an LDE induced case by IM treatment. TREATMENT AND OUTCOME: Histological Confirmation and promptly dermatological consultation relieved successfully the cutaneous adverse event. DISCUSSION: Ongoing expansion of IM usage in a wide spectrum of new indications is more likely to make physicians experience such LDE cutaneous side effects more often. Hence, they should be highly suspicious to early detect these distinct histologic entities, handle these undesired complications and guarantee satisfactory immediate outcomes, avoiding frivolous IM dosage modifications.

Occult squamous cell carcinoma within lichenoid dermatitis: three examples of cryptic cancer detection.

Lichenoid dermatitis can be a perplexing entity encompassing an array of cutaneous disorders. Two hundred forty-three (243) cases of otherwise unclassifiable lichenoid dermatitis were examined histologically employing a special cytokeratin stain. Occult squamous cell carcinoma was detected in three of the 243 cases, uncovered by special immunohistochemistry staining within histologic specimens of lichenoid dermatitis. We recommend staining for cutaneous cancer becoming a routine practice in evaluating cutaneous lichenoid dermatitis.

Lymphocyte and CD62E expression in lichen planus and lichenoid reaction.

BACKGROUND: It is difficult to distinguish the clinical and histopathological aspects of oral lichen planus lesions from those of oral lichenoid reaction. Some criteria were proposed to distinguish them, mainly because they have different biological behaviors. The aim of the present study was to compare the lymphocyte population and the expression of E-selectin between these lesions. METHODS: Participants with a clinical diagnosis of oral lichen planus (GOLP) and oral lichenoid reaction (GOLR) who needed to perform a biopsy were selected. The tissue was frozen and immunostaining was performed for CD3/CD4, CD3/CD8, CD4/CLA, CD8/CLA, and CD62E. The analysis of each immunostaining was accomplished using the ImageJ program. RESULTS: In total, 25 participants with oral lichen planus and 11 with oral lichenoid reaction were seen. In the evaluation of CD3 + CD4+/CD3 + and CD3 + CD8+/CD3 + proportions, there was a higher percentage of these cells in the oral lichen planus group when compared with the oral lichenoid reaction group (p = 0.027 and p = 0.038 respectively). The average number of CLA + lymphocytes for CD4+/CLA + and CD8+/CLA + in both groups was not statistically significant (p = 0.840; d = 0.363). In GOLP, the number of CD4 + CLA+/E-selectin and CD8 + CLA+/E-selectin was not statistically significant (p = 0.951 and p = 0.454 respectively); neither in GOLR (p = 0.454 and p = 0.989 respectively). CONCLUSION: Our results indicate that CD3 + CD4+, CD3 + CD8+, CD4 + CLA+, CD8 + CLA + lymphocytes and E-selectin are present in both lesions. However, the proportion of CD3 + CD4+/CD3 + and CD3 + CD8/CD3 + cells is higher in the oral lichen planus group when compared with the oral lichenoid reaction group, suggesting that these cells may be important for the etiopathogenic mechanism of these lesions.

Oral lichenoid lesion in association with chemotherapy treatment for non-Hodgkin lymphoma or lichen planus? Review of the literature and report of two challenging cases.

BACKGROUND: The diagnosis of oral lichenoid lesions (OLL) remains a challenge for clinicians and pathologists. Although, in many cases, OLL cannot be clinically and histopathologically distinguishable from oral lichen planus (OLP), one important difference between these lesions is that OLL has an identifiable etiological factor, e.g. medication, restorative material, and food allergy. The list of drugs that can cause OLL is extensive and includes anti-inflammatory drugs, anticonvulsants, antihypertensives, antivirals, antibiotics, chemotherapeutics, among others. This work aimed to perform a literature review of OLL related to chemotherapy drugs and to report two cases of possible OLL in patients with B-cell and T-cell non-Hodgkin lymphomas in use of chemotherapy and adjuvant medications. We also discuss the challenge to clinically and histopathologically differentiate OLL and OLP. CASE PRESENTATION: In both cases, oral lesions presented reticular, atrophic, erosive/ulcerated, and plaque patterns. The diagnosis of OLL was initially established in both cases by the association of histopathology and history of onset of lesions after the use of medications. Although the patients have presented a significant improvement in the oral clinical picture for more than 2 years of follow-up, they still have some lesions. CONCLUSION: A well-detailed anamnesis associated with the drug history, temporal relationship of the appearance of the lesions, and follow-up of patients are fundamental for the diagnosis of OLL related to drugs. Nevertheless, its differentiation from OLP is still a challenge.

Comparison of biomarker expression in oral lichen planus and oral lichenoid lesions.

BACKGROUND: Oral lichen planus (OLP) and oral lichenoid lesions (OLL) comprise a group of oral mucosal disorders that have similar clinical and histological features. OBJECTIVES: To compare the levels of investigated biomarkers in biopsied OLP and OLL, and to determine the pattern of biomarkers, which could be useful for the biological characterization of these 2 disorders. MATERIAL AND METHODS: A total of 56 biopsy specimens in 2 groups were analyzed in this study. One group consisted of 25 idiopathic OLP lesions, and the other included 31 OLL from patients treated with antihypertensive and cardiac medications. The expression of protein p53, topoisomerase I (topo I), heat shock protein 90 (HSP90), and E-cadherin was analyzed using immunohistochemistry. RESULTS: The p53 protein expression showed a trend to a positive correlation with topo I expression in the total sample (p = 0.067, R = 0.25). The p53 protein and HSP90 expression was higher in the OLL group compared to the OLP group, but the difference was not statistically significant. No association was found between topo I and E-cadherin expression for either the OLP or OLL group. CONCLUSIONS: The findings of this study suggest that the slightly higher protein p53 and HSP90 expression in the OLL group might be caused by the medications used. The slight association between p53 and topo I expression indicates that the cooperation between these proteins might be essential for the growth of OLP/OLL in general. We conclude that the overexpression of p53 protein and high expression of topo I found in both types of lesions might induce their biologically aggressive behavior.

Clinical features of oral lichen planus and oral lichenoid lesions: an oral pathologist's perspective.

The clinicopathological features that precisely characterize oral lichen planus (OLP) and oral lichenoid lesions (OLL) still represent a challenge. The aim of the present study was to analyze, from an oral pathologist perspective, the clinical features from OLP and OLL. Specimens fullfilling the histological criteria for OLP and OLL, and also compatible with OLP (OLP-C), were selected and clinical information was retrieved from the laboratory forms. The final sample was composed by 221 cases, including 119 OLP (53.8%), 65 OLP-C (29.4%) and 37 OLL (16.7%). Females were more affected in the three groups, but the number of males was higher in OLL. Mean age was lower in OLP (52.3 years) in comparison with OLL (57.9 years) (p=0.020). Buccal mucosa and tongue involvement was more frequent in OLP; gingival involvement was uncommon in OLL. The reticular pattern was more frequently found in OLP, while the association of reticular and atrophic/erosive/ulcerated patterns was more common in OLP-C and OLL (p=0.025). In conclusion, gender and mean age of the patients, and anatomical location and clinical manifestation of OLL are different from OLP, and could help to better characterize this group of conditions. Specimens diagnosed as OLP-C showed clinical parameters close to OLP.

Immunoexpression of oral brush biopsy enhances the accuracy of diagnosis for oral lichen planus and lichenoid lesions.

BACKGROUND: This study assessed the efficacy of using oral liquid-based brush cytology (OLBC) coupled with immunostained cytology-derived cell-blocks, quantified using machine-learning, in the diagnosis of oral lichen planus (OLP). METHODS: Eighty-two patients diagnosed clinically with either OLP or oral lichenoid lesion (OLL) were included. OLBC samples were obtained from all patients before undergoing surgical biopsy. Liquid-based cytology slides and cell-blocks were prepared and assessed by cytomorphology and immunocytochemistry for four antibodies (Ki-67, BAX, NF-κB-p65, and AMACR). For comparison purposes, a sub-group of 31 matched surgical biopsy samples were selected randomly and assessed by immunohistochemistry. Patients were categorized according to their definitive diagnoses into OLP, OLL, and clinically lichenoid, but histopathologically dysplastic lesions (OEDL). Machine-learning was utilized to provide automated quantification of positively stained protein expression. RESULTS: Cytomorphological assessment was associated with an accuracy of 77.27% in the distinction between OLP/OLL and OEDL. A strong concordance of 92.5% (κ = 0.84) of immunostaining patterns was evident between cell-blocks and tissue sections using machine-learning. A diagnostic index using a Ki-67-based model was 100% accurate in detecting lichenoid cases with epithelial dysplasia. A BAX-based model demonstrated an accuracy of 92.16%. The accuracy of cytomorphological assessment was greatly improved when it was combined with BAX immunoreactivity (95%). CONCLUSIONS: Cell-blocks prepared from OLBC are reliable and minimally-invasive alternatives to surgical biopsies to diagnose OLLs with epithelial dysplasia when combined with Ki-67 immunostaining. Machine-learning has a promising role in the automated quantification of immunostained protein expression.

Lichen planus pemphigoides: A unique form of bullous and lichenoid eruptions secondary to nivolumab.

The widespread use of PD-1 inhibitors to treat various solid tumors has brought certain challenges for the clinician, including immune-related adverse events (irAEs). Cutaneous toxicities are among the most observed irAEs. Bullous and lichenoid dermatoses following PD-1 inhibitor therapy have been described. Here we report a novel case of lichen planus pemphigoides, featuring characteristics of both bullous pemphigoid and lichen planus, in a patient treated with nivolumab for renal cell carcinoma. We subsequently review all three cutaneous conditions which may arise in the context of PD-1 inhibitor therapy.

Photodynamic treatment as a promising strategy applied in lichenoid tissue reaction/interface dermatitis with moderate-to-severe dysplasia: A case report.

Lichenoid tissue reaction/interface dermatitis represents a class of mucocutaneous inflammatory diseases which share common histopathological manifestations. One patient presented to our clinic whose oral lesions could not categorized into a definitely clinical or pathological diagnosis, but could be ascribed to lichenoid tissue reaction/interface dermatitis with moderate-to-severe dysplasia. Photodynamic treatment was applied in this case and a satisfactory result was eventually achieved. Signs of recurrence were not revealed at the follow-up of the tenth month.