Postoperative permanent section evaluation of Mohs micrographic surgery debulk specimens does not result in upstaging of cutaneous squamous cell carcinoma compared to stage at the completion of surgery: A retrospective case series

Background

Mohs micrographic surgery (MMS) is used for the treatment of high-risk cutaneous squamous cell carcinoma (cSCC). MMS examines the surgical margins in real time and does not commonly examine the central component of the tumor.

Objective

To determine if debulk specimens provide additional details relevant to tumor staging not gained from routine MMS.

Methods

A retrospective chart review of debulk specimens taken during MMS for cSCC was performed. Dermatopathology reports were analyzed and tumors were staged using Brigham and Women's Hospital and American Joint Committee on Cancer's 8th edition staging systems.

Results

Permanent section evaluation of debulk specimens did not result in clinically meaningful information for staging that could not be gained from MMS layers or initial biopsy analysis.

Limitations

A single institution, and a small sample size of 39 tumors.

Conclusions

Evaluation of debulk specimens during MMS may not always be an effective use of time or health care resources.

Eosinophils in psoriasis: A systematic review and meta-analysis introducing a study quality assessment tool for diagnostic pathology studies

BACKGROUND

The histopathologic features of psoriasis are well-documented, but recent studies have highlighted atypical features, such as eosinophils, in clinically confirmed cases.

METHODS

A systematic review exploring eosinophils in psoriasis was performed. A novel quality assessment tool (SQAT-Path) we designed for cross-sectional pathology studies was employed.

RESULTS

Five studies (N = 218) were identified. The pooled prevalence of dermal eosinophils in psoriasis was 46% (95% confidence interval, 0.27-0.66). The prevalences of 1 to 5 lesional eosinophils (24%) compared to >5 eosinophils (26%) were similar. There was no association between eosinophils and prior treatment. There was also no association between eosinophils and spongiosis. In SQAT-Path, studies scored between 9 and 18 (out of a maximum of 27: "fair" to "good"), consistent with the ratings using other assessment tools.

CONCLUSION

Eosinophils were found in approximately half of systematically studied and published cases of psoriasis. When present, their quantity is variable, with the likelihood of having greater than 5 eosinophils in a biopsy section comparable to having between 1 and 5. Greater than 5 eosinophils, as an isolated finding, would not be typical of psoriasis, but should not preclude its diagnosis without considering the overall histologic context.

Dermatopathologist accuracy in classifying angioinvasive fungal infections using virtual microscopy

BACKGROUND

Due to perceived difficulty in the categorization of angioinvasive fungal infections based on histopathology, variation exists in dermatopathology reporting.

METHODS

This study characterized the diagnosis of angioinvasive fungal infections by light microscopy at a single academic institution over an 11-year period. Subsequently, the accuracy of blinded reclassification by virtual microscopy was measured.

RESULTS

Seventy-six specimens with hematoxylin-eosin slides were obtained from 33 patients. The mean diagnostic accuracy of dermatopathologists in differentiating mucormycosis, hyalohyphomycosis, and phaeohyphomycosis based on blinded reclassification via virtual microscopy was 74%, with a range of 65%-91%.

CONCLUSIONS

While there was a range in diagnostic accuracy, the highest score of 91% and the identification of common sources of error suggest that histopathologic categorization of angioinvasive fungal infections can frequently be performed. However, accurate identification is not always possible given common pitfalls in diagnosis. In addition, standardized and clinically useful reporting should be considered.

Relationship between dermoscopic and histopathological findings of extradigital glomus tumors

In extradigital glomus tumors, (1) noncontact and (2) contact dermoscopy show (1) a central purplish-white area corresponding to tumor nests surrounding enlarged vessels, a peripheral yellow-white area corresponding to mucin deposition, melanin granules, and fibrous tissue, and (2) white reticular and linear cord areas corresponding to pseudocapsules and collagen fibers.

Unresectable infantile myofibroma discovered in utero

The authors present a case of a proliferative nodule located beneath an infant's lower lip that was initially discovered on prenatal ultrasound and fetal magnetic resonance imaging (MRI). Biopsy revealed a smooth muscle actin-positive spindled cell proliferation with hemangiopericytoma-like vessels consistent with infantile myofibromatosis (IM). Since the location prevented surgical management, the clinicians opted to observe the lesion. Ultimately, the lesion fully regressed on its own confirming conservative management is an option for isolated IM.

Retrospective assessment of immunologic and histologic heterogeneity in granuloma annulare by cytokine staining

BACKGROUND

Type 1 (Th1) and Type 2 (Th2) immunity have both been implicated in granuloma annulare (GA). To what extent these pathways contribute to clinical/histologic heterogeneity and/or distinct disease endotypes remains unexplored.

METHODS

We retrospectively analyzed 30 GA biopsies with either palisaded or interstitial histology with and without eosinophils. We performed RNA in situ hybridization to assess how markers of Type 1 (interferon gamma), Type 2 (interleukin [IL]4, IL13, IL5), and Type 3 (IL17A) immunity in GA compared with canonical inflammatory disorders and whether markers correlated with histology. We analyzed another cohort of 14 patients who had multiple biopsies across anatomic space and time for individual conservation of histologic features.

RESULTS

Interferon (IFN)G staining is highest in GA relative to other cytokines. Type 2 cytokine staining is less prominent, with IL4 increased in interstitial pattern cases. Eosinophils did not correlate with Type 2 markers. Patients with multiple biopsies display intrapatient variability in histology.

CONCLUSION

Type 1 inflammation predominates over Type 2 inflammation in GA irrespective of histologic pattern. Distinct disease endotypes were not detected.

Intratarsal Keratinous Cyst Clinically Misdiagnosed as a Chalazion

The intratarsal keratinous cyst (IKC) is a recently described entity, often clinically misdiagnosed as a chalazion. We report a case of a 61-year-old male patient with a chief complaint of a small lesion on the upper eyelid that evolved over six months. On physical examination, an asymptomatic, firm nodule was identified on the left upper eyelid. The patient reported no history of trauma. A provisional diagnosis of chalazion was established, and an excisional biopsy was performed. Histopathologically, the lesion was lined with a stratified squamous epithelium, with a corrugated epithelial surface showing abrupt keratinization without keratohyalin granules, and compact keratinous-appearing material in the cystic lumen. The diagnosis was IKC. No signs of recurrence were observed after one year of follow-up. It is essential to accurately diagnose IKC and distinguish it from chalazion and epidermal inclusion cysts, because IKC requires complete surgical excision and can exhibit multiple recurrences if not properly removed.

Reappraisal of psoriasis pathogenesis: the role of TEAD4 expression in keratinocytes

BACKGROUND

Psoriasis is an immune-mediated inflammatory skin disorder with a multifaceted pathogenesis. Immune dysregulation and immune cell dysfunction are among the mechanisms involved. TEA domain family member 4 (TEAD4) is suggested to play a role in psoriasis development. TEAD4 expression in keratinocytes may have a chemotactic effect and could disturb the function of FOXP3-positive T lymphocytes. This study aimed to evaluate the expressions of TEAD4 and FOXP3 in lesional, nonlesional psoriatic, and healthy skin and assess the clinical impact of their expression.

METHODS

This case-control study included 32 cases with psoriasis vulgaris and 32 control groups. Hematoxylin and eosin-stained slides were examined to evaluate the histopathological findings. Moreover, other sections were immunohistochemically stained with FOXP3 and TEAD4.

RESULTS

FOXP3 was expressed in inflammatory cells in 56.5, 37.5, and 12.5% of lesional, nonlesional, and healthy skin, whereas it was entirely negative in the keratinocytes. TEAD4 was expressed in keratinocytes in 93.7 and 46.9% of lesional and nonlesional skin, while negative in healthy skin. Significant differences were observed between their lesional, nonlesional, and healthy skin expressions. Furthermore, FOXP3 expression in lesional skin was significantly associated with early onset (P = 0.016), low PASI score (P = 0.002), mild psoriasis (P = 0.007), and axial affection (P = 0.022), while TEAD4 expression was associated with progressive course (P = 0.032), high PASI score (P = 0.002), severe psoriasis (P = 0.001), severe inflammation (P = 0.001), and progressive course (P = 0.017).

CONCLUSION

TEAD4 expression was higher in lesional than nonlesional skin and absent in healthy skin, suggesting a role in psoriasis development. TEAD4 expression was also associated with severe and progressive psoriasis. This may be mediated by the downregulation of FOXP3 and dysfunction of Treg cells. TEAD4 could serve as a promising therapeutic target in psoriasis.

Cutaneous Collagenous Vasculopathy: A Rare Entity Treated With Pulsed Dye Laser

Cutaneous collagenous vasculopathy (CCV) is a rare idiopathic dermal microangiopathy. Clinically, it presents as diffuse cutaneous telangiectasias that are indistinguishable from other benign vascular entities, thereby posing a diagnostic challenge. We present a case of CCV successfully treated with pulsed dye laser (PDL). A 27-year-old male presented with generalized erythematous macules, diagnosed as CCV via histopathology. After a successful test spot, PDL treatment resulted in significant improvement. The pathogenesis of CCV involves altered dermal microvasculature and veil cell activation. Epidemiologically, it primarily affects Caucasians, most often in the middle-aged adult population. A negative family history of similar lesions can help narrow down the differential diagnosis. Diagnosis requires biopsy, with histopathological examination demonstrating vessel ectasia and collagenous vessel wall thickening. Given its rarity, CCV presents diagnostic and management challenges though PDL emerges as a promising treatment modality for this condition.

Clinicopathologic correlation of dermatologic diseases in patients with darker pigmentation

OBJECTIVES

Cutaneous diseases that disproportionately affect patients with darker pigmentation and their histologic features are historically understudied and undertreated. This review article aims to highlight the key clinical features, histopathology, and diagnostic pearls of several cutaneous diseases that commonly present in patients with darker pigmentation.

METHODS

A literature search was conducted, and a list of cutaneous diseases that frequently affect patients with darker pigmentation was compiled. A group of experts expounded upon those that were most common or misdiagnosed according to scientific evidence and clinical practice.

RESULTS

The diseases were divided into hypopigmented disorders, hyperpigmented disorders, scarring disorders, and alopecic disorders. Within each category, the etiology, clinical features, histopathology, and key histologic differential diagnoses are described and discussed.

CONCLUSIONS

As many clinicians are taught that there are no effective treatment options or that these diseases are considered "cosmetic" in nature, patients often do not get a thorough medical workup or skin biopsy. This article aims to decrease the knowledge gap and serve as a resource for anyone involved in the care of patients with these cutaneous conditions.

Characterization of PRAME immunohistochemistry reveals lower expression in pediatric melanoma compared to adult melanoma

Pediatric melanomas are rare tumors that have clinical and histological differences from adult melanomas. In adult melanoma, the immunohistochemical marker PRAME is increasingly employed as a diagnostic adjunct. PRAME is also under investigation as a target structure for next-generation immunotherapies including T-cell engagers. Little is known about the characteristics of PRAME expression in pediatric melanoma. In this retrospective study, samples from 25 pediatric melanomas were compared with control groups of melanomas in young adults (18-30 years; n = 32), adult melanoma (>30 years, n = 30), and benign melanocytic nevi in children (0-18 years; n = 30) with regard to the immunohistochemical expression of PRAME (diffuse PRAME expression >75%/absolute expression). Pediatric melanomas show lower diffuse PRAME expression (4%) and lower absolute PRAME expression (25%) compared to young adult melanomas (15.6%/46.8%) and adult melanomas (50%/70%). A significant age-dependent expression could be observed. An analysis of event-free survival shows no prognostic role for PRAME in pediatric melanoma and young adult melanoma, but a significant association with diffuse PRAME expression in adulthood. The age dependency of PRAME expression poses a potential pitfall in the diagnostic application of melanocytic tumors in young patients and may limit therapeutic options within this age group. The immunohistochemical expression of the tumor-associated antigen PRAME is an increasingly important diagnostic marker for melanocytic tumors and is gaining attention as a possible immunotherapeutic target in melanoma. As the available data primarily stem from adult melanoma, and given the clinical and histological distinctions in pediatric melanomas, our understanding of PRAME expression in this specific patient group remains limited. The age-dependent low PRAME expression shown here constrains the use of this marker in pediatric melanoma and may also limit the use of immunotherapeutic strategies against PRAME in young patients.

Artificial intelligence and skin cancer

Artificial intelligence is poised to rapidly reshape many fields, including that of skin cancer screening and diagnosis, both as a disruptive and assistive technology. Together with the collection and availability of large medical data sets, artificial intelligence will become a powerful tool that can be leveraged by physicians in their diagnoses and treatment plans for patients. This comprehensive review focuses on current progress toward AI applications for patients, primary care providers, dermatologists, and dermatopathologists, explores the diverse applications of image and molecular processing for skin cancer, and highlights AI's potential for patient self-screening and improving diagnostic accuracy for non-dermatologists. We additionally delve into the challenges and barriers to clinical implementation, paths forward for implementation and areas of active research.

Waxy papules, infiltrated alopecic plaques, and shin ichthyosis

A 38-year-old male presented with waxy papules, plaques over the neck and extremities, and ichthyotic scales over the lower limbs. Skin biopsy revealed a dense medium-sized lymphocytic infiltrate in the dermis, with perifollicular accentuation and focal exocytosis into the follicular epithelium with strong positivity for CD 3, 4, and 5. Considering the clinicopathological correlation, a diagnosis of follicular mycosis fungoides (FMF) was made. It is a variant of classic mycosis fungoides (MF) where atypical cells invade the follicular epithelium.

Diffuse neurofibroma with hypertrichosis in a toddler

Diffuse neurofibroma is a rare type of neurofibroma uncommonly reported in infancy. It is a slow growing tumor originating in the peripheral nerve sheath. We present the case of a 17-month-old boy with diffuse neurofibroma of the scalp associated with hypertrichosis. His genetic and clinical workup for neurofibromatosis was negative.

Sepsis Associated With Aggressive Cutaneous Angiosarcoma

Cutaneous angiosarcoma is an aggressive tumor most commonly presenting on the head and neck. In this case report, we describe the presentation of sepsis secondary to an aggressive and rapidly expanding wound, located in a sun-protected area on the body, in a patient with multiple concurrent comorbidities. Treatment was tailored toward targeting the causative organisms, as well as identifying the histologic morphology of the pathologic legion. Histopathology and immunohistochemistry were used to confirm the diagnosis of cutaneous angiosarcoma, and the patient-centered decision surrounding palliative chemotherapy is outlined.

Angioleiomyoma of the Ankle: Case Report and Literature Review of a Rare Benign Soft Tissue Tumor

Angioleiomyoma is a benign soft tissue tumor originating in the smooth muscle of blood vessels. It most frequently presents as a painful, free-moving subcutaneous nodule in the lower extremities and is most common in middle-aged women. Angioleiomyoma is rare amongst benign foot neoplasms, and a preoperative diagnosis of angioleiomyoma is rare. We present a case of angioleiomyoma involving the ankle of a 28-year-old female. To prevent patient suffering, we emphasize the importance of an early and accurate diagnosis. Furthermore, we highlight the salient features of angioleiomyoma, which help with the early detection and differentiation of similar malignant variants, including leiomyosarcoma.

Nodular vasculitis (erythema induratum) associated with systemic minocycline

A 29-year-old Caucasian woman presented with a 3-month history of bilateral lower limb swelling with painful erythematous nodules on shins without ulceration. She had been taking minocycline for acne vulgaris for 3 years. Biochemical investigations showed deranged liver function test with positive ANA and mixed antinuclear factor (ANF) pattern. A skin biopsy was in keeping with a diagnosis of nodular vasculitis. Her skin lesions and liver function test improved within 3 months of stopping the minocycline treatment. This case report raises the awareness that minocycline could be a potential cause of nodular vasculitis, patients on minocycline should be closely monitored and minocycline should ideally not be prescribed for more than 12 weeks, given the possible adverse effects.

Real-life practice of reflectance confocal microscopy in France: A prospective multicenter study

BACKGROUND

Studies demonstrating the potential utility of reflectance confocal microscopy (RCM) have been performed under experimental conditions.

OBJECTIVE

To provide an overview of RCM practice in real-life.

METHODS

A multicenter, prospective study carried out in 10 university dermatology departments in France.

RESULTS

Overall, 410 patients were enrolled. One-half of the patients (48%) were referred by private practice dermatologists. They were referred for diagnosis (84.9%) or presurgical mapping (13%). For diagnosis, the lesions were located on the face (62%), arms and legs (14.9%), and trunk (13.6%), and presurgical mapping was almost exclusively on the face (90.9%). Among those referred for diagnosis, the main indication was suspicion of a skin tumor (92.8%). Of these, 50.6% were spared biopsies after RCM. When RCM indicated surgery, histology revealed malignant lesions in 72.7% of cases. The correlation between RCM and histopathology was high, with a correlation rate of 82.76% and a kappa coefficient of 0.73 (0.63; 0.82).

LIMITATIONS

This study was performed in the settings of French tertiary referral hospitals.

CONCLUSION

This study shows that in real-life RCM can be integrated into the workflow of a public private network, which enables a less invasive diagnostic procedure for patients.

Skin and Syntax: Large Language Models in Dermatopathology

This literature review introduces the integration of Large Language Models (LLMs) in the field of dermatopathology, outlining their potential benefits, challenges, and prospects. It discusses the changing landscape of dermatopathology with the emergence of LLMs. The potential advantages of LLMs include a streamlined generation of pathology reports, the ability to learn and provide up-to-date information, and simplified patient education. Existing instances of LLMs encompass diagnostic support, research acceleration, and trainee education. Challenges involve biases, data privacy and quality, and establishing a balance between AI and dermatopathological expertise. Prospects include the integration of LLMs with other AI technologies to improve diagnostics and the improvement of multimodal LLMs that can handle both text and image input. Our implementation guidelines highlight the importance of model transparency and interpretability, data quality, and continuous oversight. The transformative potential of LLMs in dermatopathology is underscored, with an emphasis on a dynamic collaboration between artificial intelligence (AI) experts (technical specialists) and dermatopathologists (clinicians) for improved patient outcomes.

BioMEL: a translational research biobank of melanocytic lesions and melanoma

INTRODUCTION

Diagnosing invasive cutaneous melanoma (CM) can be challenging due to subjectivity in distinguishing equivocal nevi, melanoma in situ and thin CMs. The underlying molecular mechanisms of progression from nevus to melanoma must be better understood. Identifying biomarkers for treatment response, diagnostics and prognostics is crucial. Using biomedical data from biobanks and population-based healthcare data, translational research can improve patient care by implementing evidence-based findings. The BioMEL biobank is a prospective, multicentre, large-scale biomedical database on equivocal nevi and all stages of primary melanoma to metastases. Its purpose is to serve as a translational resource, enabling researchers to uncover objective molecular, genotypic, phenotypic and structural differences in nevi and all stages of melanoma. The main objective is to leverage BioMEL to significantly improve diagnostics, prognostics and therapy outcomes of patients with melanoma.

METHODS AND ANALYSIS

The BioMEL biobank contains biological samples, epidemiological information and medical data from adult patients who receive routine care for melanoma. BioMEL is focused on primary and metastatic melanoma, but equivocal pigmented lesions such as clinically atypical nevi and melanoma in situ are also included. BioMEL data are gathered by questionnaires, blood sampling, tumour imaging, tissue sampling, medical records and histopathological reports.

ETHICS AND DISSEMINATION

The BioMEL biobank project is approved by the national Swedish Ethical Review Authority (Dnr. 2013/101, 2013/339, 2020/00469, 2021/01432 and 2022/02421-02). The datasets generated are not publicly available due to regulations related to the ethical review authority.

TRIAL REGISTRATION NUMBER

NCT05446155.

Blasts with folded nuclei: A histopathologic finding in myeloid leukemia cutis with NPM1 and FLT3 mutations

Leukemia cutis is a term used to describe cutaneous manifestations of leukemic infiltration of the skin and portends a poor prognosis. Cutaneous involvement by hematopoietic/lymphoid tumors can occur before, concurrently, or after the initial diagnosis. Early involvement of dermatologists and timely biopsies play a crucial role in achieving a prompt diagnosis. Prior reports of acute myeloid leukemia have revealed a strong association between the cup-like nuclear morphology observed in bone marrow specimens and concurrent mutations of NPM1 and FLT3-ITD. In cutaneous tissue sections of leukemia cutis, folded or indented nuclei may represent the "cup-like" counterpart previously described in bone marrow specimens. Recognizing this morphological feature could aid in identifying this molecular subtype of leukemia cutis. In this study, we present a case of leukemia cutis in a 63-year-old female with AML and NPM1 and FLT3-ITD mutations, demonstrating scattered indented/folded nuclei.

Pembrolizumab-Induced Rupioid Psoriasis Treated by Apremilast Without Interrupting the Ongoing Antineoplastic Treatment

We report the case of a 77-year-old man affected by a poorly differentiated metastatic pulmonary adenocarcinoma who, after the first course of therapy with cisplatin-pemetrexed-pembrolizumab treatment, developed rupioid psoriasis. We decided to discontinue pembrolizumab for four weeks until lesions improved and to start therapy with apremilast (an oral small molecule phosphodiesterase (PDE)4 inhibitor) in combination with systemic methylprednisolone 16 mg/day with consequent tapering until discontinuation in a few weeks. After accomplishing three months of treatment with apremilast, the patient gained complete remission of the rupioid lesions. Pembrolizumab therapy was reintroduced, and cycles were carried out without exacerbating the clinical picture. During the fourth month of therapy with apremilast, it was attempted to stop the treatment despite continuing the therapy with pembrolizumab. As a result, there was a relapse of the erythematous scaling plaques. After the subsequent reintroduction of apremilast, a new remission of the clinical picture occurred despite the absence of interruption of pembrolizumab. As far as we know, this is the second case of rupioid psoriasis induced by immunotherapy with pembrolizumab. Still, while the previous case was undergoing therapy with acitretin and methylprednisone, our patient is the first case treated with apremilast with excellent and rapid remission even after discontinuation and re-administration of pembrolizumab without exacerbation of dermatitis. In addition, the appearance of psoriasis during immunotherapy can be properly treated, which does not contraindicate the continuation of the antineoplastic treatment.

Rapidly Growing and Aggressive Squamous Cell Carcinoma of the Forearm: A Report of Successful Treatment With Mohs Surgery and Complex Reconstruction With Rhombic Triple Z-Plasty

Reconstruction of complex post-surgical wounds requires functional and aesthetic considerations. We present a case of a complex radial-dorsal forearm defect in a patient who underwent Mohs surgery for an aggressive and rapidly growing squamous cell carcinoma. Following complete tumor excision, we utilized a modified rhombic flap for complete wound coverage with long-term conservation of extensor function. The rhombic flap modification included three Z-plasties at the flap base to add rotational components to the flap transposition. Long-term follow-up showed acceptable cosmesis, preserved extensor tendon function, and no evidence of tumor recurrence.

PRAME Is an Effective Tool for the Diagnosis of Nevus-Associated Cutaneous Melanoma

(1) Background: Nevus-associated cutaneous melanoma (CM) is relatively common in the clinical practice of dermatopathologists. The correct diagnosis and staging of nevus-associated cutaneous melanoma (CM) mainly relies on the correct discrimination between benign and malignant cells. Recently, PRAME has emerged as a promising immunohistochemical marker of malignant melanocytes. (2) Methods: PRAME immunohistochemistry (IHC) was performed in 69 cases of nevus-associated CMs. Its expression was evaluated using a score ranging from 0 to 4+ based on the percentage of melanocytic cells with a nuclear expression. PRAME IHC sensitivity, specificity, positive predictive values, and negative predictive values were assessed. Furthermore, the agreement between morphological data and PRAME expression was evaluated for the diagnosis of melanoma components and nevus components. (3) Results: PRAME IHC showed a sensitivity of 59%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 71%. The diagnostic agreement between morphology and PRAME IHC was fair (Cohen's Kappa: 0.3); the diagnostic agreement regarding the benign nevus components associated with CM was perfect (Cohen's Kappa: 1.0). PRAME was significantly more expressed in thick invasive CMs than in thin cases (p = 0.02). (4) Conclusions: PRAME IHC should be considered for the diagnostic evaluation of nevus-associated CM and is most useful in cases of thick melanomas. Pathologists should carefully consider that a PRAME-positive cellular population within the context of a nevus could indicate a CM associated with the nevus. A negative result does not rule out this possibility.

White Fibrous Papulosis of the Neck in a 70-Year-Old Female: A Case Report

White fibrous papulosis of the neck (WFPN) manifests through the presence of numerous solid, persistent, and asymptomatic yellowish-white papules, displaying a distinctive asymmetrical distribution primarily localized on the neck and antecubital fossa. This case report describes the clinical presentation of a 70-year-old female diagnosed with WFPN, highlighting the significant finding of collagen fiber thickening upon histopathological analysis. Despite its predilection for specific anatomical sites, the elusive pathogenesis of WFPN adds diagnostic complexity, emphasizing the need for further research in this unique condition that generally follows a benign course.

A Case of Pleomorphic Dermal Sarcoma: Giant Exophytic Tumor of the Medial Canthus

We present the case of a 99-year-old Caucasian female who was referred for treatment of a painless, 8.0 cm × 7.8 cm exophytic, pedunculated, ulcerated tumor of the left medial canthus. Pathology showed spindled, oval, and polygonal cells with pleomorphic nuclei. Many multinuclear giant cells and mitotic figures were also noted. The tumor was highlighted with CD10, showed focal positivity with actin, desmin, and CD68, and had increased Ki67 immunohistochemical staining. The tumor was negative for pancytokeratin, CK5/6, p63, MART-1/MelanA, S100, Sox10, p40, CD34, and CD23. Based on clinicopathologic correlation, the diagnosis of pleomorphic dermal sarcoma (PDS) was made. Pleomorphic dermal sarcoma (PDS) refers to a deep, histologically high-grade tumor that often resembles other tumors clinically and histologically. As PDS is frequently aggressive and related to adverse outcomes, it is important to recognize its distinguishing features in comparison to other similar entities, including atypical fibroxanthoma (AFX) and pleomorphic leiomyosarcoma (PLMS). To our knowledge, there is only one other reported case in the literature of PDS occurring on the eye. By reviewing and understanding characteristic etiologies, locations of presentation, histopathological features, and management techniques, pathologists can make a more accurate diagnosis and dermatologists can provide more effective patient care in a timely manner.