Diagnostic Utility of Direct Immunofluorescence on Paraffin-Embedded Skin Biopsy Samples for the Diagnosis of Autoimmune Vesiculobullous Lesions

Background Autoimmune vesiculobullous diseases (AIBDs) are a group of diseases characterized by blisters of the skin/mucosa due to the presence of circulating autoantibodies against antigens in the epidermis or the dermo-epidermal junction. Direct immunofluorescence (DIF) for immunoglobulin (Ig)G, IgC3, and IgA on fresh-frozen tissue is the gold standard diagnostic test for AIBDs. However, DIF in the absence of frozen tissue is challenging for the diagnosis of AIBDs. This study aimed to analyze the practical utility of DIF using paraffin-embedded skin biopsy rather than fresh frozen tissue for the diagnosis of AIBDs. Methodology This cross-sectional comparative study included 30 cases of AIBDs. DIF for IgG and IgA was performed on paraffin-embedded tissue (PE-DIF) after proteinase digestion on histopathologically confirmed 15 pemphigus vulgaris (PV), three pemphigus foliaceous (PF), four bullous pemphigoid (BP), three dermatitis herpetiformis (DH), three subcorneal pustular dermatosis (SCPD), and one case each of linear IgA disease and pemphigoid gestationis (PG). PE-DIF staining pattern was compared with the DIF on fresh frozen tissue (FF-DIF). Results All cases of PV and PF showed an intercellular IgG chicken wire staining pattern similar to FF-DIF. However, background staining was more intense in PV cases while less intense in PF cases. Three BP cases showed linear IgG staining in PE-DIF. DH, SCPD, linear IgA disease, and PG cases did not show IgG positivity. Out of three DH cases, two cases showed granular IgA positivity while linear IgA positivity along the basement membrane was seen in a single case of linear IgA disease. Negative IgG staining was observed in SCPD. Immunofluorescence in PE-DIF was rapidly deteriorating than in FF-DIF. Conclusions DIF done on paraffin-embedded tissue can be used as a supplement and salvage technique with histopathology for the diagnosis of AIBDs, particularly when a cryostat facility for frozen tissue is not available and the patient is unable to undergo a second biopsy procedure.

Role of cytopathology in diagnosing phaeohyphomycosis masquerading as nerve abscess in a lepromatous leprosy patient: A case report

INTRODUCTION AND IMPORTANCE

Phaeohyphomycosis is a rare fungal infection primarily affecting immunocompromised individuals. Its clinical manifestations are diverse, and diagnosis can be challenging, particularly when lesions mimic other conditions.

CASE PRESENTATION

A 66-year-old male, with a history of irregular leprosy treatment and prolonged steroid use, presented with symptoms suggestive of a nerve abscess. On examination, cystic swellings were observed on the left thumb and leg. Histopathological examination and fine needle aspiration cytology (FNAC) revealed melanized hyphae, leading to a final diagnosis of phaeohyphomycosis. The patient was treated with oral itraconazole, leading to regression in lesion size.

CLINICAL DISCUSSION

Leprosy patients on long-term steroids are especially susceptible. The pathogenicity of these fungi in immunocompetent people is believed to be due to melanin in their cell walls, which defends against host defenses. Diagnosis involves histopathological examinations, staining, and fungal culture. Treatment involves surgical excision and antifungal drugs. If untreated, it can lead to severe complications including fatal brain infections.

CONCLUSION

This case highlights the unusual presentation of phaeohyphomycosis mimicking a nerve abscess in a leprosy patient. It underscores the importance of a high degree of clinical suspicion in diagnosing such rare infections, particularly in immunocompromised individuals. It also emphasizes the value of FNAC in reaching a definitive diagnosis. Prompt diagnosis and appropriate treatment are essential to prevent potentially serious outcomes.

Unraveling the Enigma of Perforating Itches: A Comprehensive Report of Reactive Perforating Collagenosis in Three Patients

Reactive perforating collagenosis (RPC) is a rare dermatosis where dermal connective tissue erupts through the epidermis, resulting in diverse clinical manifestations such as umbilicated papules with crusting and excoriated nodules with central puncta. Associated with systemic disorders like diabetes mellitus, chronic kidney diseases, and autoimmune conditions, RPC's pathogenesis involves abnormal collagen metabolism, immune dysfunction, genetic predisposition, and environmental triggers. Histopathological examination reveals vertically oriented shallow cup-shaped invaginations containing degenerated collagen fibers, aiding diagnosis. Treatment includes managing underlying causes and utilizing options like topical corticoids, retinoids, and phototherapy, with a possibility of spontaneous regression and recurrence. This case report highlights the significance of considering RPC in patients with characteristic skin lesions and severe itching, emphasizing early recognition and accurate diagnosis to optimize patient care. Continued research and collaboration are crucial for improving outcomes in individuals affected by RPC.

Clinico-Histological Correlation in Hansen's Disease: Three-year Experience at a Newly Established Tertiary Care Center in Central India

BACKGROUND

Hansen's disease is a chronic infectious disease caused by Mycobacterium leprae. It is characterized by a wide range of clinical and histological manifestations. Ridley-Jopling criteria are widely used for classifying leprosy. The demonstration of acid-fast bacilli on slit-skin smear examination and in skin biopsy aids in its diagnosis.

AIM

The aim of the present study was to perform clinico-histological correlation of skin lesions in all patients with a clinical suspicion of Hansen's disease.

MATERIALS AND METHODS

The study included skin biopsies of all suspected cases of Hansen's disease received over a period of 3 years. Hematoxylin and eosin and Fite-Faraco stained sections of all cases were examined. Corresponding slit-skin smears, if available, were also reviewed.

RESULTS

During the study, a total of 116 cases were clinically diagnosed as Hansen's disease. Clinico-histological correlation was obtained in 62.9% of the cases (73/116). The most common histological subtype of Hansen's disease was borderline tuberculoid (TT) (40/116). Seven cases were diagnosed as lepromatous leprosy, five as TT, four as histoid, one as indeterminate, and three cases diagnosed as erythema nodosum leprosum. Fite-Faraco stain was positive in 33/73 cases. Out of 116 cases, slit-skin smears were available for 43 cases and were positive in 23 cases.

CONCLUSION

Correlation between clinical, bacteriological, and morphological features is required for accurate classification of Hansen's disease. Clinical detection and morphological diagnosis of early lesions remain challenging, and the histological findings should always be interpreted in correlation with clinical findings.

Fixed-drug Eruptions: What can we Learn from a Case Series?

BACKGROUND

A fixed-drug eruption (FDE) is a unique cutaneous adverse drug effect in the form of recurrent lesions at the same site after re-exposure to the offending agent.

AIM

The aim of the study was to identify changes in trends in fixed drug eruptions with regard to causative drug or patient risk factors.

METHODS

Cases of FDEs encountered between March 2014 to May 2017 during routine pharmacovigilance activities were analyzed.

RESULTS

FDEs made up 8.4% of total adverse drug reactions and 11.1% of cutaneous reactions. Majority of the patients were adults between 18 and 45 years old. The average lag period between drug intake and appearance of FDE was 2.04 days. Commonly affected sites were extremities, lips, head and neck, and genitalia. Number of FDE lesions varied from 1 to > 6, with nearly half the patients (46%) presenting with a single lesion. Antimicrobials (80.6%) and nonsteroidal anti-inflammatory drugs (20.8%) were most frequent drugs implicated. Route of administration was oral for all causative drugs. History of an FDE was positive in 26 (50.2%) of the cases. Majority of the patients (21 out of 25 or 84%) whose lesions appeared within minutes to hours of suspected drug intake had a history of FDE. Furthermore, 66.7% of patients with multiple lesions had a history of FDE while only 34.8% of patients with a single lesion had such a history.

CONCLUSION

FDEs are common cutaneous reactions with antimicrobials and anti-inflammatory agents, with increased likelihood of extensive and multiple lesions in patients with a history of FDE.

Cytomorphology of Skin Adnexal Tumors: A Tale of Two Scalp Swellings

The primary and metastatic tumors of the skin can be effectively diagnosed by fine needle aspiration cytology (FNAC); however, the cytomorphological features of skin adnexal tumors are rarely described in the literature. We hereby describe the cytological features of two histologically confirmed cases of benign skin adnexal tumors. Case 1 is of a 46-year-old female who presented with an elevated firm nodule over the scalp. A cytological diagnosis of benign adnexal tumor possibly of sebaceous origin was given. The nodule was excised and histopathological examination confirmed the diagnosis of sebaceoma. Case 2 is of a 19-year-old male who presented with a pigmented scalp swelling. Cytomorphological features were suggestive of benign skin adnexal tumor with foci of melanin pigment. The swelling was excised and histopathological examination confirmed the diagnosis of eccrine poroma. To the best of our knowledge, only one previous report of sebaceoma and no report of eccrine poroma describing the cytological findings of these two tumors exist. We report these two cases of benign skin adnexal tumors to discuss the cytological features and the potential diagnostic dilemma that they pose to the cytologist.

Multinodular fibroepithelioma of Pinkus with an isolated focus of evolving basal cell carcinoma in chronic lymphedematous lower limb

Fibroepithelioma of Pinkus (FEP) is a rare, indolent variant of basal cell carcinoma (BCC) with a unique anastomosing type of epidermal hyperplasia. Certain benign and neoplastic conditions including BCC are known to develop in a setting of chronic lymphedema. We report for the 1st time the histological spectrum of evolution of a large exophytic multinodular FEP, bearing a single initiating focus of BCC, in preexisting chronic lymphedema of the lower limb. The lesion possibly evolved from long-standing local immune suppression, and clinically resembled a high-grade carcinoma. Oozing lymphatic fluid may interfere with the success of skin grafting following wide local excision in a lymphedematous limb, thus offering a challenging scenario from the management point of view.

Diagnostic Utility and Pitfalls of Tzanck Smear Cytology in Diagnosis of Various Cutaneous Lesions

Aims:

Tzanck smear is an old but useful test for diagnosis of cutaneous dermatoses. The aim of this study was to highlight the potential usefulness and diagnostic pitfalls of Tzanck smear for diagnosis of cutaneous dermatoses and infections.

Materials and Methods:

This hospital based cross-sectional study was carried out on all Tzanck smears received for a period of twenty months (January 2014–August 2015). The smears were assessed to establish the utility of Tzanck smears in corroborating or excluding a diagnosis of immunobullous lesion or herpetic infection. Cases with discrepant diagnosis on histopathology were reviewed to identify additional cytomorphological features.

Results:

A total of 57 Tzanck smears were performed during the study period. Out of the 18 clinically suspected cases of immunobullous disorders, Tzanck smear findings corroborated the clinical diagnosis in 7/18 cases, one case was diagnosed as cutaneous candidiasis, and diagnosis of immunobullous lesions could be excluded in 5/18 cases. Out of the 19 suspected cases of herpetic infections, viral cytopathic effect was observed in 8/19 cases. Besides immunobullous lesions and herpetic infections, acantholytic cells were also observed in spongiotic dermatitis and genodermatosis. Dyskeratotic keratinocytes seen in vacuolar interface dermatitis were not easily distinguishable from acantholytic cells on Tzanck smear.

Conclusions:

Tzanck smear test is an inexpensive and useful diagnostic tool for certain skin diseases. It can aid in establishing a rapid clinical diagnosis and can serve as a useful adjunct to routine histological examination. We recommend the use of Tzanck smear as a first-line investigation for vesiculobullous, erosive, and pustular lesions.

Dowling-Degos disease with reticulate acropigmentation of Kitamura: Extended spectrum of a single entity

Dowling-Degos disease (DDD) and reticulate acropigmentation of Kitamura (RAK) are rare genodermatoses inherited as an autosomal dominant trait with variable penetrance. They are considered to be part of a spectrum of reticulate pigmentary dermatoses, characterized by the presence of hyperpigmented macules coalescing in a reticular fashion. The authors describe a 28-year-old male patient having hyperpigmented macules on the axillae, neck and face, reticulate acropigmentation of dorsum of the hands, forearms and feet, palmar pitting, and comedo-like lesions over back. The patient showed the unique clinical as well as histopathological overlap of both the rare diseases (DDD and RAK), substantiating the hypothesis that they represent two different features of a single entity with variable phenotypic expression.

Oral bioavailability enhancement of exemestane from self-microemulsifying drug delivery system (SMEDDS)

Limited aqueous solubility of exemestane leads to high variability in absorption after oral administration. To improve the solubility and bioavailability of exemestane, the self-microemulsifying drug delivery system (SMEDDS) was developed. SMEDDS comprises of isotropic mixture of natural or synthetic oil, surfactant, and cosurfactant, which, upon dilution with aqueous media, spontaneously form fine o/w microemulsion with less than 100 nm in droplet size. Solubility of exemestane were determined in various vehicles. Ternary phase diagrams were plotted to identify the efficient self-emulsification region. Dilution studies, droplet size, and zeta potential of the formulations were investigated. The release of exemestane from SMEDDS capsules was studied using USP dissolution apparatus in different dissolution media and compared the release of exemestane from a conventional tablet. Oral pharmacokinetic study was performed in female Wistar rats (n = 8) at the dose of 30 mg kg(-1). The absorption of exemestane from SMEDDS form resulted in about 2.9-fold increase in bioavailability compared with the suspension. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds, such as exemestane by the oral route.