Clinical and allelic heterogeneity in dystrophic epidermolysis bullosa- lessons from an Indian cohort

BACKGROUND

Dystrophic epidermolysis bullosa (DEB) is due to variation in the COL7A1 gene. The clinical phenotype and severity depends on the type of variation and domain of the affected protein.

OBJECTIVES

To characterize the spectrum of COL7A1 variations in a cohort of DEB patients from India, to correlate these findings with clinical phenotypes and to establish a genotype-phenotype correlation.

METHODS

This was a retrospective, observational study involving patients with DEB diagnosed on the basis of clinical manifestations, Immuno-fluorescence antigen mapping (IFM) and genetic analysis. A genotype-phenotype correlation was attempted and observations were further explained using IFM on skin biopsies and molecular dynamic simulations. Descriptive statistics were performed using SPSS version 20.0 with P values of <0.05 considered significant.

RESULTS

We report 68 unrelated Indian DEB patients classified as RDEB-Intermediate (RDEB-I), RDEB-Severe (RDEB-S) or DDEB based on the EB diagnostic matrix, immunofluorescence antigen mapping and genetic data. Of 68 DEB patients, 59 (86.76%) were inherited in a recessive pattern (RDEB) and 9 (13.24%) in a dominant pattern (DDEB). Limbal stem cell deficiency was seen in four cases of RDEB-S very early in the course of the disease. A total of 88 variants were detected of which 66 were novel. There were no hotspots and recurrent variations were seen in a very small group of patients. We found a high frequency of compound heterozygotes (CH) in RDEB patients born out of non-consanguineous marriage. RDEB patients older than two years who had oral mucosal involvement, and/or deformities, were more likely to have esophageal involvement. Genotype phenotype correlation showed a higher frequency of extracutaneous manifestations and deformities in patients with Premature Termination Codons (PTCs) than in patients with other variations. Molecular simulation studies in patients with missense mutations showed severe phenotype when they were localized in interrupted regions of GLY-X-Y repeats.

CONCLUSION

This large study of DEB patients in South Asia adds to the continually expanding genetic database of this condition. This study has direct implications on management as this group of patients can be screened early and managed appropriately.

Clinical heterogeneity in epidermolysis bullosa simplex with plectin (PLEC) mutations-A study of six unrelated families from India

Epidermolysis bullosa simplex (EBS) with plectin mutations is a very rare subtype of EB usually associated with pyloric atresia (PA) or muscular dystrophy (MD). We report six unrelated children between ages 4 and 14 years from India with varied clinical manifestations. Only one had PA, and none has developed MD to date. All except the one with PA presented with early onset blistering along with laryngeal involvement in the form of hoarseness of voice and nail involvement. Patient with PA presented with aplasia cutis and died in the first week. Two patients had predominantly respiratory and gastrointestinal involvement with varying severity while two had features of myasthenic syndrome but no limb-girdle involvement and one patient phenocopied laryngo-onycho-cutaneous (LOC) syndrome. Using whole-exome sequencing, we identified novel mutations in PLEC. Histopathological analysis (Immunofluorescence antigen mapping) showed absence of staining to plectin antibodies. Our observations propose to append a phenotype of EBS, hoarseness of voice and nail dystrophy or LOC-like phenotype with plectin mutations. Long-term follow up is necessary to monitor for the development of muscular dystrophy.

Perineal warty plaques: A case of verrucous porokeratosis

Nonvenereal genital dermatoses form an important category of disorders, and verrucous porokeratosis is a rare and less recognized entity among the same. We present the case of a young adult male with warty growths over scrotum and buttocks for a year. Characteristic cornoid lamellae with typical differentiating features were seen in the histopathology, establishing the diagnosis. This case emphasizes the rare nonvenereal cause for a condition clinically mimicking condyloma acuminata.

Severe epidermolysis bullosa/Kindler syndrome-like phenotype of an autoinflammatory syndrome in a child

A 5-year-old boy presented with generalized cutaneous erosions, severe scarring, depigmentation and contractures affecting major joints. The lesions had initially affected his ears, nose, feet, and the genital and ocular mucosa, leading to significant depigmentation, scarring, contractures and mutilation. The whole of the trunk and limbs were involved at the time of presentation, with the exception of some islands of spared skin on the proximal thighs, legs, nipples and external genitalia. Electron microscopy revealed a split in the sublamina densa with the absence of anchoring fibrils, suggestive of dystrophic epidermolysis bullosa (EB). Immunofluorescence antigen mapping demonstrated a broad reticulate pattern of staining with collagen IV, VII, and laminin 332 in the floor of the blister, suggestive of Kindler syndrome. Next-generation sequencing revealed a de novo heterozygous missense mutation (a variant of unknown significance) in exon 22 of the phospholipase-C gamma 2 gene (PLCG2), which resulted in a substitution of serine by asparagine at codon 798 (p.Asp798Ser), a result that was validated using Sanger sequencing. The child was diagnosed with PLCG2-associated antibody deficiency and immune dysregulation (PLAID)/autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) syndrome. The cutaneous and corneal erosions, inflammation and scarring of this magnitude, and the eventual result of death have not been described previously for the PLAID/APLAID spectrum previously. In conclusion, this was an unusual acquired autoinflammatory severe EB-like disease that may be associated with de novo PLCG2 mutation.

Relevant diagnostic implications of the therapeutic challenge with antitubercular therapy in an unusual case of sarcoidosis mimicking lupus vulgaris

Cutaneous manifestations in sarcoidosis are seen in 25-35% of patients with systemic disease and may be the sole manifestation in few patients. It is known that isolated cutaneous sarcoidosis is a great mimicker and can be easily misdiagnosed as other granulomatous conditions especially lupus vulgaris in regions with high burden of tuberculosis (TB). Here we present a case with cutaneous sarcoidosis who was initially misdiagnosed and treated as bifocal lupus vulgaris with antitubercular therapy (ATT) for 6 months. This nonresponsiveness to therapy prompted us to investigate the patient further for other differentials, failing which a diagnosis of cutaneous sarcoidosis was made and the patient was treated with oral steroids and methotrexate with complete clearance of lesions after 14 weeks of therapy. Our case reemphasizes the value of therapeutic trial of ATT in diagnosis of cutaneous TB and highlights the remarkable clinical mimic of sarcoidosis with lupus vulgaris.

Silvery hair with dyschromatosis: Griscelli syndrome type 3 or familial gigantic melanocytosis

We herein illustrate a case of an adult male presenting with silvery hair and generalized guttate hypopigmented macules on a background of diffuse cutaneous hyperpigmentation, since birth. Histopathology showed enlarged melanocytes with abundant melanin. Based on these clinicopathological features, differential diagnoses considered were Griscelli syndrome 3 (GS3) and familial giagantic melanocytosis. GS3 belongs to a group of inherited autosomal recessive (AR) disorders of partial albinism, known as silvery hair syndromes, while familial gigantic melanocytosis (FGM) is a putative disorder of dyschromia with silvery hairs. A pertinent literature search revealed hyperpigmentation or dyschromatosis as a rare manifestation of silvery hair syndromes, especially in dark-skin populations. A comparative analysis of previously reported cases depicted close morphological similarities between GS3 and FGM. We discuss the uncertainty pertaining to cases described in literature as FGM, to be truly representative of a distinctive entity, or merely a morphological variation of GS3.

Argyria an unrecognized cause of cutaneous pigmentation in Indian patients: a case series and review of the literature

Argyria is an uncommon grey-blue pigmentation of skin and mucous membranes caused by prolonged silver exposure. The impetus behind this review is our experience with cases of generalized argyria resulting from a uniquely Indian socio-cultural practice and belief that it is under reported. Our objective is to increase the awareness for this esoteric entity through a review of the pertinent literature and to highlight clinical and histological features using our four well worked-up cases as examples.

Tumor of follicular infundibulum: an unsuspected cause of macular hypopigmentation

We present three cases of a rare eruptive variant of tumor of follicular infundibulum. Two patients presented with hypopigmented macules. The clinical differential diagnoses considered in these two cases were vitiligo, lichen sclerosus et atrophicus, and idiopathic guttate hypomelanosis. In the third case, the lesions were hypopigmented flat topped maculo-papules diagnosed clinically as verruca plana. In all three cases, the histopathological features of plate like growth of pale keratinocytes connected to the epidermis and peritumoral condensation of elastic fibers were diagnostic. Although no satisfactory treatment is available, the exclusion of other clinical differential diagnosis particularly vitiligo with its psychosocial implications underscores the importance of skin biopsy.

Sclerosing lymphocytic lobulitis in a male patient with asthma

Sclerosing lymphocytic lobulitis is commonly but not exclusively associated with type I diabetes mellitus. Association with other autoimmune diseases is known and also disease is infrequently seen in males. We herein report a rare case of sclerosing lymphocytic lobulitis in a male patient with asthma. Recognition of this entity in the absence of diabetes and awareness of its existence in males is important to avoid unwarranted surgical procedures because it may mimic carcinoma both clinically and radiologically.

Uterine primitive neuroectodermal tumor with adenosarcoma: a case report

Introduction

Primitive neuroectodermal tumor of the uterus is extremely rare. They occur as either pure primitive neuroectodermal tumors or admixed with neoplasms of mullerian origin.

Case presentation

A case of uterine primitive neuroectodermal tumor with adenosarcoma in a 50-year-old Asian Indian woman is presented. Histologically, the neoplasm displayed perivascular pseudorosettes and occasional Homer-Wright rosettes. A strong positivity for neuronspecific enolase and synaptophysin was noted, while chromogranin and CD99 were negative. Merging imperceptibly with the neuroectodermal components were the areas of adenosarcoma.

Conclusion

To the best of our knowledge, this report represents the second case of a uterine primitive neuroectodermal tumor with an admixed adenosarcoma.

Pleomorphic adenoma with squamous and appendageal metaplasia mimicking mucoepidermoid carcinoma on cytology

Background:

Histological diversity is the hallmark of pleomorphic adenoma, the most common salivary gland tumor. It may cause difficulty in cytological interpretation, due to limited and selective sampling.

Case presentation:

A 16-year-old female patient presented with right cheek swelling. Fine needle aspiration cytology showed squamous cells, basaloid cells, and foamy cells, along with extracellular keratin and foreign body giant cells. Characteristic metachromatic fibrillary chondromyxoid stroma, which is usually seen in pleomorphic adenoma, was not seen in the aspirate. A diagnosis of mucoepidermoid carcinoma was given on cytology. Subsequent resection revealed an encapsulated pleomorphic adenoma, with extensive squamous metaplasia and appendageal differentiation on histology.

Conclusion:

This case illustrates that pleomorphic adenoma with squamous metaplasia presents a potential for misinterpretation as mucoepidermoid carcinoma on cytology. We discuss the various pitfalls and the features that are helpful in distinguishing these two lesions.