Machine learning for classification of cutaneous sebaceous neoplasms: implementing decision tree model using cytological and architectural features

BACKGROUND

This observational study aims to describe and compare histopathological, architectural, and nuclear characteristics of sebaceous lesions and utilized these characteristics to develop a predictive classification approach using machine learning algorithms.

METHODS

This cross-sectional study was conducted on Iranian patients with sebaceous tumors from two hospitals between March 2015 and March 2019. Pathology slides were reviewed by two pathologists and the architectural and cytological attributes were recorded. Multiple decision tree models were trained using 5-fold cross validation to determine the most important predictor variables and to develop a simple prediction model.

RESULTS

This study assessed the characteristics of 123 sebaceous tumors. Histopathological findings, including pagetoid appearance, neurovascular invasion, atypical mitosis, extensive necrotic area, poor cell differentiation, and non-lobular tumor growth pattern, as well as nuclear features, including highly irregular nuclear contour, and large nuclear size were exclusively observed in carcinomatous tumors. Among non-carcinomatous lesions, some sebaceoma and sebaceous adenoma cases had features like high mitotic activity, which can be misleading and complicate diagnosis. Based on multiple decision tree models, the five most critical variables for lesion categorization were identified as: basaloid cell count, peripheral basaloid cell layers, tumor margin, nuclear size, and chromatin.

CONCLUSIONS

This study implemented a machine learning modeling approach to help optimally categorize sebaceous lesions based on architectural and nuclear features. However, studies of larger sample sizes are needed to ensure the accuracy of our suggested predictive model.

Whole transcriptome-based skin virome profiling in typical epidermodysplasia verruciformis reveals α-, β-, and γ-HPV infections

HPVs are DNA viruses include approximately 450 types that are classified into 5 genera (α-, β-, γ-, μ-, and ν-HPV). The γ- and β-HPVs are present in low copy numbers in healthy individuals; however, in patients with an inborn error of immunity, certain species of β-HPVs can cause epidermodysplasia verruciformis (EV), manifesting as recalcitrant cutaneous warts and skin cancer. EV presents as either typical or atypical. Manifestations of typical EV are limited to the skin and are caused by abnormal keratinocyte-intrinsic immunity to β-HPVs due to pathogenic sequence variants in TMC6, TMC8, or CIB1. We applied a transcriptome-based computational pipeline, VirPy, to RNA extracted from normal-appearing skin and wart samples of patients with typical EV to explore the viral and human genetic determinants. In 26 patients, 9 distinct biallelic mutations were detected in TMC6, TMC8, and CIB1, 7 of which are previously unreported to our knowledge. Additionally, 20 different HPV species, including 3 α-HPVs, 16 β-HPVs, and 1 γ-HPV, were detected, 8 of which are reported here for the first time to our knowledge in patients with EV (β-HPV-37, -47, -80, -151, and -159; α-HPV-2 and -57; and γ-HPV-128). This study expands the TMC6, TMC8, and CIB1 sequence variant spectrum and implicates new HPV subtypes in the pathogenesis of typical EV.

Ichthyosis follicularis syndromes in patients with germline mutations in GJB2

Ichthyosis follicularis (IF) manifests as generalized spiny follicular projections found in syndromic diseases secondary to SREBF1 and MBTPS2 mutations. We sought the genetic cause of IF in two distinct families from a cohort of 180 ichthyosis patients. In Family 1, the proband presented with IF, bilateral sensorineural hearing loss (SNHL) and punctate palmoplantar keratoderma, and compound heterozygous GJB2 mutations were discovered in DNA from peripheral blood lymphocytes: GJB2:c.526A>G and c.35delG. In Family 2, the proband presented with a previously unreported IF phenotype in the context of KID syndrome, and whole-exome sequencing found a de novo heterozygous GJB2:c.148G>A mutation. Histopathology was consistent with porokeratotic eccrine ostial and dermal duct nevus (PEODDN) and IF in Probands 1 and 2, respectively. Our findings add to the clinical and histopathological spectrum of IF and emphasize the association of PEODDN-like entities with GJB2 variants.

Cutaneous granular cell tumor: A case series, review, and update

Background

Granular cell tumor (GCT) or Abrikossoff's tumor is an uncommon neuro-derived tumor in which Schwann cells are found and express S-100 protein. Often, it is a benign lesion. Histopathologically, there are granular cell infiltrations through the entire dermis without necrosis which are periodic acid Schiff (PAS) stain positive and reactive with S-100. The aim of this study is the clinicopathological evaluation of GCT.

Material and Methods

In this paper, we described the experience of 6 patients with a GCT in different locations (4 cases in the skin and 2 cases in the mucosa), for example, a case with a tumor in the abdomen and a keloidal-like presentation with a highly sclerotic pattern (an uncommon pathological feature). Another case developed a lesion secondary to physical trauma.

Result

In one case, the presence of a lesion in the lower lip associated with actinic damage secondary to chronic sun exposure resulted in misdiagnosis with actinic cheilitis and squamous cell carcinoma.

Conclusion

Histopathologically, there were granular cell infiltrations through the entire dermis without necrosis which are PAS-positive and reactive with S-100.

Ichthyosis, psoriasiform dermatitis, and recurrent fungal infections in patients with biallelic mutations in PERP

BACKGROUND

Germline autosomal dominant and autosomal recessive mutations in PERP, encoding p53 effector related to PMP-22 (PERP), a component of epidermal desmosomes, have been associated with a spectrum of keratodermas. Monoallelic nonsense mutations cause Olmsted syndrome with severe periorificial keratoderma and palmoplantar keratoderma (PPK). Biallelic recessive frameshift and missense mutations are associated with milder forms of the disease, including generalised erythrokeratoderma and PPK.

OBJECTIVES

To add new insights into the genotype-phenotype correlations as a consequence of PERP mutations and to provide a comprehensive review of the literature.

METHODS

Among 26 previously unresolved families within a cohort of 180 extended Iranian families with syndromic or non-syndromic ichthyosis, two families with shared clinical features were examined by whole-exome sequencing and genome-wide homozygosity mapping. Mycological and dermatopathological studies were performed to further characterise their atypical phenotypic presentations.

RESULTS

In two unrelated multiplex consanguineous families affected by ichthyosis, two novel biallelic PERP variants, NM_022121.5, c.89T > C, p.Leu30Pro and c.466G > C, p.Gly156Arg, located inside of genomic homozygosity regions of the probands were detected. Interestingly, some patients had areas of scaly psoriasiform plaques on the background of generalised ichthyosis that appeared during active cutaneous fungal infections. Mycological examinations of these lesions revealed infections caused by Candida albicans, Epidermophyton floccosum, or Trichophyton rubrum. Histopathology of the psoriasiform lesions shared some features with psoriasis, which when combined with clinical presentation, led to incorrect diagnosis of guttate psoriasis or pustular psoriasis.

CONCLUSIONS

PERP variants in ichthyosis patients can confer susceptibility to recalcitrant cutaneous fungal infections. Additionally, patients with episodic psoriasiform dermatitis in the setting of keratoderma should be considered for PERP genotyping and cutaneous fungal examinations.

Prevalence and Main Determinants of BRAF V600E Mutation in Dysplastic and Congenital Nevi

Background & Objective:

Predicting the transformation of dysplastic or congenital nevi into malignant lesions results in a significant increase in the survival of patients. Some specific gene mutations have been reported to be very helpful in this regard. Therefore, this study aimed to evaluate the prevalence of BRAF V600E mutation in dysplastic and congenital nevi.

Methods:

This cross-sectional study was conducted on patients with congenital (n=30) or dysplastic (n=30) nevi. For genomic analysis, the BRAF gene mutation (V600E) was evaluated using the real-time polymerase chain reaction.

Results:

The prevalence of BRAF gene (V600E) mutation was found as 1 case (3.3%) in congenital and 8 cases (26.7%) in dysplastic nevi indicating the higher prevalence of this mutation in patients with dysplastic nevi (P=0.026). Moreover, in the dysplastic nevi group, the presence of BRAF gene mutation (V600E) showed a significant relationship with the severity of dysplasia as the mutation rate was 25% in mild cases, in comparison with 54.5% in moderate dysplasia cases (P=0.009).

Conclusion:

According to the results, 3.3% of the patients with congenital nevi and 26.7% of the subjects with dysplastic nevi were positive for BRAF V600E mutation. Furthermore, the severity of dysplasia could have a positive relationship with the presence of the mutation.

Diagnostic value of cytology in oral ulcer and comparison with histopathology and direct immunofluorescence

Rapid diagnosis of pemphigus vulgaris (PV) is an important task in patient's prognosis and treatment. Although PV is routinely diagnosed through investigation of pathology specimens and direct immunofluorescence assays, Tzanck smear can be used as rapid, inexpensive, and easily used test to confirm its clinical diagnosis. This study aimed to determine the diagnostic value of Tzanck smear in erosive oral lesions of PV and also determine its sensitivity and specificity for diagnostic purposes. A total of 68 patients with erosive/ulcerated oral lesions were included in this study and divided into PV (case group) vs other causes of erosive oral lesions (control group). From all participants, two Tzanck smears were prepared for both Giemsa and hematoxylin-eosin (H&E) staining. For definite diagnosis, histopathology and direct immunofluorescence evaluations were performed based on clinical findings. The sensitivity of acantholytic cells in Tzanck smear of erosive oral lesions of PV cases was 80.5% (for both Giemsa and H&E staining), whereas specificity values of Giemsa and H&E staining were 84.6% and 96.3%, respectively. Based on our findings, the Tzanck smear of erosive oral lesions is a simple, quick, and inexpensive test for screening and primary diagnosis of PV.

New diagnostic markers in basal cell carcinoma

Background:

The clinical significance of plasma lipoprotein levels in the diagnosis and prognosis of certain diseases is known fact. Some studies have reported different and contradictory levels of blood lipoproteins in cancer patients. Therefore, we decided to compare lipid profiles in patients with basal cell carcinoma (BCC) and healthy individuals.

Materials and Methods:

In this case-control study, lipid biomarkers in blood plasma of 64 patients with BCC compared with biomarkers in 64 healthy subjects. According to including criteria's both group selected. 5 cc blood samples taken after 8–12 h of fasting. Ultimately, the diagnosis of biopsy samples confirmed by the dermatopathologist. The information data entered into the PASS II software and then characterized by a descriptive and analytical statistics of the lipid profile. The role of the related factors was assessed by two sample t-test power analysis.

Results:

In this research, mean age of patient group and the healthy one was 67.13 ± 11.33 and 64.31 ± 6.98, respectively. The average amount of triglyceride, cholesterol, high density lipoprotein (HDL) and low density lipoprotein in the BCC patients were 147.97 ± 87.11 mg/dl, 188.25 ± 38.90 mg/dl, 61.98 ± 18.61 mg/dl and 95.98 ± 31.69 mg/dl, respectively, whereas these amounts in the control group were 137.34 ± 61.41 mg/dl, 173.22 ± 38.79 mg/dl, 42.34 ± 7.83 mg/dl and 106.44 ± 35.17 mg/dl, respectively. There were statistically significant differences between cholesterol and HDL in patients with BCC and healthy controls, respectively (P = 0.030) (P < 0.001).

Conclusion:

It seems that changes in lipid profile can help as a diagnostic marker for detecting cancer like BCC. Although this change could be different in lipid markers and also among different types of cancer.

Basal cell carcinoma associated with erythema ab igne

Erythema ab igne is a skin condition mainly caused by heat exposure. Erythema ab igne usually follows a favorable prognosis. However, it may increase the risk of developing cutaneous malignancy in the involved skin. Being familiar with the type of cutaneous malignancies that may arise in the site of erythema ab igne is considerably important. To our knowledge, this letter presents the first case that shows the association between erythema ab igne and basal cell carcinoma.

Evaluation of Th17 associated antigen in Old World Cutaneous Leishmaniasis: A comparative study in acute versus chronic human cutaneous Leishmaniasis using immunohistochemistry

There are little information about Th17 cells and cutaneous Leishmaniasis (CL), due to an important effect of Th17 cells on immune response, it is worth to explore the role of Th17 on CL. The purpose of this study was to assess Th17 population in patients with acute vs. chronic CL lesions in comparison with skin samples collected from healthy volunteers in an endemic region of Old World CL. A total of 49 patients with clinical manifestations of chronic (n=16) and acute (n=33) CL lesions were recruited. The clinical diagnosis of CL was confirmed by direct smear or PCR. Biopsy specimens from prelesional skin of non-infectious lesions of 30 healthy individuals were used as control. Tissue sections of 3µm thickness were prepared and used for immunohistochemistry (IHC) analysis with primary antibody specific for Th17 associated antigen (CD161). For IHC, Envision+ (DakoCytomation) system was used and developed by using diaminobenzidine (DakoCytomation). The mean age of 33 patients with acute CL and the mean age of 16 patients with chronic CL were accordingly 45.24±16.43 and 33.56±15.87. In acute and chronic CL the mean (±standard deviation) and median (±interquartile range) were accordingly 2.92±2.21, 2.56±2.9 and 2.1±1.99, 1.54±2.81. In healthy controls the mean (±standard deviation) and median (±interquartile range) were 0.72±0.41 and 0.61±0.58 respectively. With pairwise comparison of acute, chronic and control groups, there were significant difference between acute and control (P value < 0.001), chronic and control (P value = 0.043). The results showed that there was an increasing cellular response of Th17 in both acute and chronic CL patients. Th17 was significantly higher in patients with acute and chronic CL lesions in comparison with healthy control group. However, there was no significant difference between acute and chronic infection concerning to Th17 cells.

DNA plasmid coding for Phlebotomus sergenti salivary protein PsSP9, a member of the SP15 family of proteins, protects against Leishmania tropica

BACKGROUND

The vector-borne disease leishmaniasis is transmitted to humans by infected female sand flies, which transmits Leishmania parasites together with saliva during blood feeding. In Iran, cutaneous leishmaniasis (CL) is caused by Leishmania (L.) major and L. tropica, and their main vectors are Phlebotomus (Ph.) papatasi and Ph. sergenti, respectively. Previous studies have demonstrated that mice immunized with the salivary gland homogenate (SGH) of Ph. papatasi or subjected to bites from uninfected sand flies are protected against L. major infection.

METHODS AND RESULTS

In this work we tested the immune response in BALB/c mice to 14 different plasmids coding for the most abundant salivary proteins of Ph. sergenti. The plasmid coding for the salivary protein PsSP9 induced a DTH response in the presence of a significant increase of IFN-γ expression in draining lymph nodes (dLN) as compared to control plasmid and no detectable PsSP9 antibody response. Animals immunized with whole Ph. sergenti SGH developed only a saliva-specific antibody response and no DTH response. Mice immunized with whole Ph. sergenti saliva and challenged intradermally with L. tropica plus Ph. sergenti SGH in their ears, exhibited no protective effect. In contrast, PsSP9-immunized mice showed protection against L. tropica infection resulting in a reduction in nodule size, disease burden and parasite burden compared to controls. Two months post infection, protection was associated with a significant increase in the ratio of IFN-γ to IL-5 expression in the dLN compared to controls.

CONCLUSION

This study demonstrates that while immunity to the whole Ph. sergenti saliva does not induce a protective response against cutaneous leishmaniasis in BALB/c mice, PsSP9, a member of the PpSP15 family of Ph. sergenti salivary proteins, provides protection against L. tropica infection. These results suggest that this family of proteins in Ph. sergenti, Ph. duboscqi and Ph. papatasi may have similar immunogenic and protective properties against different Leishmania species. Indeed, this anti-saliva immunity may act as an adjuvant to accelerate the cell-mediated immune response to co-administered Leishmania antigens, or even cause the activation of infected macrophages to remove parasites more efficiently. These findings highlight the idea of applying arthropod saliva components in vaccination approaches for diseases caused by vector-borne pathogens.

Folliculotropic Mycosis Fungoides: Clinical and Histologic Features in Five Patients

BACKGROUND

Alopecia can be a manifestation of mycosis fungoides (MF); however, the prevalence is unknown.

AIMS

We sought to describe the clinicopathologic presentation of alopecia in patients with diagnosis of MF.

METHODS

A retrospective analysis of patients with biopsy-proven MF, who were evaluated at our cancer center from 2002 to 2012, was performed to identify patients with alopecia.

RESULTS

Five patients with alopecia were identified from reviewing of 157 patients with MF. The male:female ratio was 3:2, and the mean age of patients was 42.8 years. Two of these patients showed patchy hair loss on scalp which was clinically identical to alopecia areata. In remaining three patients, hair loss was seen in areas of MF lesions, and epidermal changes consisted of patch- and plaque-type lesions of MF, tumors, and follicular lesions (follicular MF) were also present. In two of these patients, lymphadenopathy without any visceral involvement was detected.

CONCLUSIONS

Alopecia was observed in 5 (3.18%) patients with MF, which makes it a rare finding, which included alopecia areata-like patchy loss in 2 and alopecia within MF lesions in 3.

The expression of MMP-2 and Ki-67 in head and neck melanoma, and their correlation with clinic-pathologic indices

OBJECTIVE

Melanoma is an aggressive tumor with propensity for early metastasis and poor prognosis with delayed diagnosis. Matrix metalloproteinase-2 (MMP-2) is involved in degradation of extra-cellular matrix proteins and tumor progression. Ki-67 is a predictor of tumor proliferation activity but its prognostic significance in melanoma is controversial. In this study, the prognostic value of MMP-2 and Ki-67 via immuno-staining in head and neck melanoma is investigated.

MATERIAL AND METHODS

A retrospective analysis of 24 consecutive primary melanoma samples was performed. All samples were stained with monoclonal MMP-2 and Ki-67 antibodies. Two independent investigators evaluated the stained sections. The reactive cells were considered positive regardless of the staining intensity and reported as percentage.

RESULTS

A strong correlation between MMP-2 expression, Breslow tumor thickness, and Clark level of invasion was observed (r = 0.85, P < 0.0001 and r = 0.84, P < 0.0001, respectively). A significant positive correlation was observed between MMP-2 expression and number of lymph node involved (r = 0.55, P value 0.005). MMP-2 over expression (>50%) was an independent predictor of lymph node involvement (OR: 2.1, P value: 0.01). No significant association was observed between Ki-67 expression and Breslow tumor thickness, Clark level, or lymph node involvement.

CONCLUSION

MMP-2 expression correlates with tumor thickness in melanoma and is an independent predictive factor for lymph node involvement.

Diagnostic accuracy of BP180 NC16a and BP230-C3 ELISA in serum and saliva of patients with bullous pemphigoid

BACKGROUND

Bullous pemphigoid (BP) is a subepidermal blistering disease, characterized by autoantibodies directed against BP180 and BP230. Collecting saliva is an easy and painless way of obtaining biological samples, and can be used for diagnosis of autoimmune diseases.

AIM

To compare the diagnostic accuracy of serum and salivary BP180-NC16a and BP230-C3 in the initial diagnosis of BP.

METHODS

We assessed 50 patients newly diagnosed with BP and 50 healthy controls. The diagnosis of BP was confirmed based on clinical, histopathological and immunofluorescence findings. Serum and saliva samples were collected from both groups, and BP180 and BP230 titres were assessed using commercially available ELISA kits.

RESULTS

Using serum, the sensitivity of the serum BP180 and BP230 ELISA assays was 88% and 48%, respectively, and the specificity of both was 96%. Using saliva with the cutoff value proposed by the manufacturer, sensitivity was 56.2% and 14.6%, and specificity was 98% and 100%, respectively. Using the best calculated cutoff for saliva, sensitivity increased to 87.5% and 77.1%, and specificity to 96% and 62%, respectively. There was a significant correlation between serum and saliva BP180 levels and the severity of skin disease. Both serum and saliva BP230 levels were significantly higher in patients with mucosal involvement.

CONCLUSION

Serum BP180 NC16a ELISA is a sensitive and specific test for the initial diagnosis of BP, whereas serum BP230-C3 ELISA is highly specific, but less sensitive. Saliva may be a noninvasive and convenient alternative for use in the BP180 NC16a ELISA to diagnose BP.

Nodular colloid degeneration of the skin: Report of three cases with review and update

Nodular colloid degeneration (NCD) is a rare dermatological disorder and uncommon type of colloid milium. The degeneration may be related to sun exposure. In this report, three cases, all presenting as multiple plaques and nodules over the nose and the face are depicted. Histologically, these nodular masses were homogeneous, with eosinophilic-cleaved materials expanding the papillary dermis and extending into the deep dermis. Periodic acid Schiff (PAS), crystal violet, and methyl-violet stains highlight the colloid material. All the three cases were finally diagnosed as NCD. NCD could be considered in any case with facial nodules and a long history of sun exposure. We suggest the long-term sun exposure as an etiologic factor; thus sun protection would be the most preventive and available treatment.

Clinicopathological study of 1016 consecutive adnexal skin tumors

Adnexal tumors (ATs) are primary skin tumors with benign or rarely, malignant behavior. They have been classified based on differentiation towards hair follicle, sebaceous, apocrine or eccrine gland. Few large-scale studies have focused on ATs. To determine the prevalence of ATs and to assess clinical and histopathological trend of ATs. A retrospective descriptive study of all ATs diagnosed in Razi hospital between 2006 and 2010 was performed. A total of 30,000 pathology records were reviewed, and 1016 ATs were included. The prevalence of ATs was 3.3%. 518 patients (51%) were female, with a mean age of 34.5 years. 953 tumors (93.8%) were benign. ATs were most commonly located in the head and neck area (822, 83.5%). The most common histopathological origin of ATs was sebaceous gland (536, 52.7%). Sebaceous nevus of Jadassohn was the most prevalent single tumor type (40.6% of all ATs). In 63.6% (646) of tumors, ATs were clinically suspected by the clinician prior to biopsy. The most common malignant AT was sebaceous carcinoma (23, 36.5% of all malignant ATs). ATs are infrequent lesions, most commonly occurring in 3rd and 4th decade of life. Diagnosis of ATs is made by histopathological studies as they often express indistinctive clinical features. Malignant ATs are rare, occur at an older age, and are often hard to recognize clinically.