Congenital Unilesional Cutaneous Langerhans Cell Histiocytosis: A Case Report
Abstract: Langerhans cell histiocytosis (LCH) is a clonal proliferation of bone-marrow-derived cells, which normally reside as epidermal and mucosal dendritic cells involved in antigen presentation. It is a rare disease more common in children than adults, that is believed to be neoplastic in most cases. The diagnosis is based on clinical and radiological findings in combination with histopathologic, immunophenotypic, or ultrastructural analyses. LCH have a broad spectrum of clinical manifestations, ranging from benign cutaneous lesions to malignant multisystem disease. Based on the extent of involvement at diagnosis, ...
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Fungating Areolar Mass in a Woman With No Medical History: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

Persistent Arcuate Annular Rash: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

Firm Nodule on the Right Upper Medial Arm: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

Unilateral Acral Keratotic Papules and Punctate Pits: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

Melanocytic Hyperactivation Simulating an Acral Lentiginous Melanoma in a Patient With Parkinson Disease Treated by Levodopa
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Letters to the Editor Source Type: research

Cutaneous Endothelial Dysfunction and Complement Deposition in COVID-19
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Letters to the Editor Source Type: research

It has the Erythema of a Lichen Planopilaris, it has the Hyperkeratosis of a Lichen Planopilaris, but it is Not a Lichen Planopilaris: About the “Lichen Planopilaris-Like” Form of Folliculitis Decalvans
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Letters to the Editor Source Type: research

Fungating Areolar Mass in a Woman With No Medical History: Answer
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Answer Source Type: research

Persistent Arcuate and Annular Rash: Answer
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Answer Source Type: research

Firm Nodule on the Right Upper Medial Arm: Answer
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Answer Source Type: research

Unilateral Acral Keratotic Papules and Punctate Pits: Answer
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Answer Source Type: research

Secondary Syphilis With Elastophagocytosis: An Unusual Histologic Finding
In this report, we present a unique case of secondary syphilis. (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Primary Cutaneous Desmoplastic Melanoma With Collagen Rosettes and Pseudoglandular Features
Abstract: Primary cutaneous desmoplastic melanoma (DM) is a group of rare melanocytic tumors arising on severely sun-damaged skin, histologically characterized by the proliferation of spindled melanocytes in a prominent desmoplastic stroma, with a range of morphological presentations. In this article, we report a unique case of primary cutaneous DM composed of a nodular proliferation of highly pleomorphic spindled and epithelioid cells, pseudoglandular structures, clear cell change, and unusual collagen rosettes. Immunohistochemical analysis showed a strong and diffuse positivity for S-100 protein, SOX-10, nestin, p75 ...
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

S100/CD34-Positive Spindle Cell Mesenchymal Neoplasm Harboring KIAA1549-BRAF Fusion
Abstract: Mesenchymal neoplasms with oncogenic kinase activity due to genomic alterations in receptor tyrosine kinase genes are a morphologically heterogeneous group with a variable biologic potential. A subset of these neoplasms are characterized by immunophenotypic property of dual S100 protein/CD34 expression, histopathological resemblance to lipofibromatosis or peripheral nerve sheath tumors, and often alterations in neurotrophic tropomyosin-related kinase genes. In this article, we present a case of an S100 protein/CD34-positive spindle cell neoplasm harboring a rare BRAF gene rearrangement (KIAA1549-BRAF fusion) ...
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Hypopigmented Mycosis Fungoides Mimicking Vitiligo
Abstract: Hypopigmented mycosis fungoides (HMF) is a clinical variant of MF with a presentation similar to other hypopigmented diseases, especially vitiligo. In this article, we report an adult case of HMF mimicking vitiligo. A 53-year-old man presented with an asymptomatic well-defined focal and hypopigmented patch with erythematous to brownish macules on the flank which had been developing over several months without other cutaneous findings. He had no past medical or trauma history. Skin biopsy from the hypopigmented patch indicated a slightly band-like, superficial dermal infiltrate of lymphocytes with mild cytolog...
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Epithelioid Kaposi Sarcoma: A New Histological Variant
We report on a 56-year-old Peruvian man who had been diagnosed with classical KS on the right foot 2 years before the present episode. He presented in our clinic with new lesions on the left foot. Histopathological findings included areas showing epithelioid cells with moderate pleomorphism, growing in solid sheets. Immunohistochemistry showed strong nuclear staining with a granular nuclear staining pattern for human herpesvirus 8 in the epithelioid cells. A diagnosis of epithelioid Kaposi sarcoma was made, which should be considered a new histological variant. (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Kikuchi–Fujimoto Disease Triggered by Systemic Lupus Erythematosus and Mycoplasma pneumoniae Infection—A Report of a Case and a Review of the Literature
Abstract: Kikuchi–Fujimoto disease (KFD) is a necrotizing histiocytic lymphadenitis that was described for the first time in 1972 in Japan. Its etiology is still not fully understood. It has been reported in association with many different agents, diseases, and triggering factors without any conclusive result. To the best of our knowledge, we report for the first time a case of KFD with systemic lupus erythematosus in a child in association with a polymerase chain reaction (PCR)-positive throat swab for Mycoplasma pneumoniae. Although difficult to prove, the acute M. pneumoniae infection might have served as a tr...
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Review Article Source Type: research

Proliferating Pilar Tumors: Can Immunohistochemistry Differentiate Benign and Malignant Forms?
Conclusions: Our study includes the largest group of patients in whom image analysis of p53, Ki67, and p27 has been used to try to separate benign from malignant lesions. Although there were no significant differences regarding Ki67 and p53, malignant lesions have a statistically lower expression of p27. Further studies may be needed to determine the clinical usefulness of image analysis in this differential diagnosis. (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Original Study Source Type: research

Differentiation of Basal Cell Carcinoma and Trichoepithelioma: An Immunohistochemical Study
This study was divided into 2 parts. First, 17 cases of BCC and 14 cases of TE were stained with androgen receptor and bcl-2. Then, 27 cases of borderline/equivocal of BCC and 13 cases of borderline/equivocal TE were stained with the same protocol. Sensitivity and specificity were calculated for each individual immunomarker and for the combination of them. Androgen receptor positivity was 100% specific for BCC and borderline/equivocal BCC, whereas bcl-2 diffuse staining pattern demonstrated a sensitivity of 82.4% for BCC and 88.9% borderline/equivocal BCC. When both immunomarkers were combined, the sensitivity for BCC decr...
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Original Study Source Type: research

Mitotically Active Nevus and Nevoid Melanoma: A Clinicopathological and Molecular Study
In this study, we performed cytogenetic testing on a cohort of 25 mitotically active melanocytic proliferations resembling common melanocytic nevus from 25 patients. Based on cytogenetic findings, the lesions were classified as “nevoid melanoma” (n = 13) or “mitotically active nevus” (n = 12). Subsequently, we compared the clinicopathological features between these 2 groups. Nevoid melanomas occurred in older patients (P = 0.007); however, there were no significant differences in gender, size, or anatomical distribution between the 2 groups. Histologically, deep/marginal mitoses (P = 0.006), lack of...
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Original Study Source Type: research

Sebaceous Tumors of the Skin: A Study of 145 Lesions From 136 Patients Correlating Pathologic Features and DNA Mismatch Repair Staining Pattern
Abstract: Sebaceous neoplasms occur sporadically or in the setting of Muir–Torre syndrome. The data regarding the correlation of pathologic features and DNA mismatch repair (MMR) staining pattern in sebaceous tumors of the skin are very scanty and based on relatively small series of patients. The goal of this study was to correlate MMR staining pattern with selected morphological features in a series of 145 sebaceous neoplasms (sebaceous adenoma, sebaceoma, and extraocular sebaceous carcinoma) from 136 patients. Cystic change, intratumoral mucin deposits, squamous metaplasia in the absence of keratoacanthoma-like...
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: Original Study Source Type: research

Osteoclast-Like Giant Cells: Focus on Entities Relevant to Dermatopathology and Underlying Pathogenesis
Abstract: Osteoclast-like giant cells (OLGCs) resemble osteoclasts with their abundant cytoplasm and well-developed organelles. OLGCs are characteristic features of giant cell tumor of the tendon sheath and giant cell tumor of soft tissue but they have also been described in numerous other cutaneous conditions. The diagnostic and prognostic significance of the presence of OLGCs is unknown. Here, we summarize the clinical entities that can exhibit these cells to avoid a histological overlap, affecting diagnosis and management. (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - February 24, 2021 Category: Pathology Tags: CME Article Source Type: research

Caruncular Dacryops After Cataract Surgery With Histopathological Characterization
Abstract: Caruncular dacryops is a rare cyst of lacrimal tissue most commonly found in the palpebral lobe of the lacrimal gland. The exact cause of dacryops is unclear, although it may be congenital or associated with trauma, infection, or inflammation. The pathophysiology and histology of a caruncular dacryops of the left lacrimal gland in a 68-year-old woman is reported. The patient presented 3 months after a cataract surgery with symptoms of irritation and pruritus of the left eye. A 6- × 6-mm clear cyst of the lacrimal gland prolapsing into the lateral fornix was noted on physical exam. Histological examinati...
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Clear Cell Hidradenoma—Basal Cell Carcinoma Collision
Abstract: A 91-year-old man presented with a tumor on the left temporal area, clinically suspicious of basal cell carcinoma. The histopathologic study showed a central solid-cystic tumor composed by 3 different types of cells (clear or finely granular cells, polygonal cells, and squamoid cells). It had a sclerotic stroma. At the periphery, another tumor composed by smaller interconnected nests was evident. Some nests were separated from the stroma by clefts. The stroma of this second tumor was highly cellular. There was a sharp delimitation between both tumors, with no transitional area. Immunochemistry demonstrated th...
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Unilateral Maculopapular Eruption in a Child: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

Elderly Man With Progressive Nail Atrophy: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

An Elderly Man With a Firm Bluish Papule on the Dorsal Forearm: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

Erythematous Plaques in a Patient With Lung Cancer: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

Dermatologic Oncology and Histopathology at a Secondary Care Centre During the Coronavirus Disease 2019 Pandemic
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Letters to the Editor Source Type: research

Dendritic Cell Neurofibroma With Pseudorosettes: A Variant of Neurofibroma?
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Letters to the Editor Source Type: research

The Clinical Implication of Incidental Epidermodysplasia Verruciformis
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Letters to the Editor Source Type: research

Unilateral Maculopapular Eruption in a Child: Answer
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Answer Source Type: research

An Elderly Male With Progressive Nail Atrophy: Answer
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Answer Source Type: research

An Elderly Man With a Firm Bluish Papule on the Dorsal Forearm: Answer
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Answer Source Type: research

Erythematous Plaques in a Patient With Lung Cancer: Answer
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Clinical Pathologic Challenge Answer Source Type: research

Pilomatrical Tumor of Low Malignant Potential: A Tumor Between Pilomatricoma and Pilomatrical Carcinoma
We report a case of pilomatrical tumor showing intermediate histological features between pilomatricoma and pilomatrical carcinoma. The lesion recurred twice with the same histological features. Similar cases were was probably called aggressive or proliferating pilomatixoma; we think that the term pilomatrical tumor of low malignant potential is more suitable for this lesions. Excision with wide free margins and follow-up are recommended. (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Coronavirus (COVID-19) Infection–Induced Chilblains: A Brisk Perieccrine Inflammatory Response
We present the second case of biopsy-proven COVID-19 infection–induced chilblains (pernio) in a paucisymptomatic patient with a brisk perieccrine lymphocytic response. Based on an antecedent pathological study, we know coronavirus particles have been seen in the eccrine gland associated with a brisk peri-inflammatory response. The prominent perieccrine inflammation is helpful in the diagnosis of COVID-19 infections. Currently, nonischemic pathological findings correlate with a good prognosis based on the paucisymptomatic or asymptomatic nature of their disease courses. Patients presenting with suspected COVID-19 infe...
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Case of Bullous Grover Disease
Abstract: Grover disease is an acquired acantholytic dermatosis affecting middle-aged men, with pruritus being the most commonly associated symptom. Grover disease tends to wax and wane and can last between several months to several years. Although Grover disease is usually papular, we report here a patient who presented with mainly vesicular and bullous lesions on his back originally concerning for folliculitis, contact dermatitis, or disseminated herpes simplex viral infection. Skin biopsy demonstrated acantholysis, suprabasal blisters, and a predominantly lymphocytic dermal infiltrate. Tzanck preparation for giant c...
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Atypical BCL6/GATA3+ Primary Cutaneous Acral CD8-Positive T-Cell Lymphoma: A Diagnostic Challenge
We present a 53-year-old woman with an indolent solitary nodule on her right leg, which histopathologically showed features of CD8-positive T-cell lymphoma, although with some peculiarities, including epidermotropism, absence of CD68 expression, and positivity for GATA3 and Bcl6 in neoplastic cells. This case could contribute to better define the spectrum of this rare cutaneous lymphoma. (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Intravascular Cutaneous Disorders. A Clinicopathologic Review
Abstract: Intravascular proliferations of the skin are clinically heterogeneous and may present with a wide range of clinical features, including violaceous papules, nodules, plaques, or other unspecific cutaneous lesions. Histopathologically, these conditions are characterized by proliferation of different cell types within the lumina of dermal vessels and endothelial cell hyperplasia. Immunohistochemistry is the best tool to identify the nature of the intravascular proliferating cells and the type of involved vessel. In this review, we analyzed the clinicopathologic and immunohistochemical characteristics of intravas...
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Review Article Source Type: research

Psoriasis With Eczematous Features: A Retrospective Clinicopathologic Study
Conclusion: This study offers insights into the clinically and histopathologically challenging diagnosis of psoriasis vulgaris with eczematous changes and offers the diagnostic term “eczematized psoriasis” to describe these patients. The presence of allergic contact dermatitis should be considered in these patients. (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Original Study Source Type: research

Histopathological Spectrum and Immunophenotypic Characterization of Symmetrical Drug-Related Intertriginous and Flexural Exanthema
Conclusions: SDRIFE is characterized histologically by a vacuolar interface dermatitis induced by cytotoxic T lymphocytes and neutrophilic granulocytes. This pattern may be obscured by accompanying spongiotic, psoriasiform, or pustular features combined with a mixed superficial and sometimes deep dermal infiltrate. (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Original Study Source Type: research

Twenty-Eight Cases of Extraocular Sebaceous Carcinoma: A Correlative Clinicopathological and Immunohistochemical Analysis of Extraocular Sebaceous Carcinomas and Benign Sebaceous Gland Tumors
Abstract: Extraocular sebaceous carcinoma (ESC) is a rare appendiceal skin tumor. In contrast to ocular sebaceous carcinoma, information about the exact cellular architecture of these lesions is scarce and the histogenesis of ESC is unknown. Here, we extend our previous study and investigate 28 extraocular carcinomas in comparison to 54 benign sebaceous tumors and 8 cases of normal sebaceous glands using a broad spectrum of antibodies against p63, several keratins, adipophilin, EMA, Ki67, androgen receptor, and mismatch repair proteins. This observational study demonstrates that p63- and K5/14-positive basaloid cells a...
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: Original Study Source Type: research

Acneiform Presentations of Folliculotropic Mycosis Fungoides
Conclusion: We present these cases to expand the clinical and histopathologic spectrum of FMF that may strikingly resemble acneiform disorders and to highlight the importance of diagnostic reconsideration with histopathologic evaluation. (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - January 28, 2021 Category: Pathology Tags: CME Article Source Type: research

Penile Necrosis as a Presenting Sign of Purpura Fulminans Mimicking Fournier's Gangrene
We report the case of a 63-year-old white man who, 3 days after stent removal of endoscopic drainage of pancreatic cysts, developed a penile necrosis due to purpura fulminans (PF) that has been misdiagnosed as Fournier's gangrene. Penile necrosis was rapidly followed by a lethal multiorgan failure due to disseminated intravascular coagulopathy (DIC), triggered by the subsequent development of a severe acute pancreatitis. PF describes a rare syndrome involving intravascular thrombosis and hemorrhagic infarction of the skin. Although reports of penile necrosis secondary to various causes are documented in the literature, pen...
Source: The American Journal of Dermatopathology - December 24, 2020 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Case of Generalized Tumor-Type Rosai–Dorfman Disease With Sarcoidosis-Like Histological Features and IgG4-Positive Plasma Cells
We presented a case of a 55-year-old man with varying sizes of many dark red nodules and lumps over the face, trunk, and limbs for approximately 1 year but without systemic involvement. The results of the laboratory evaluations were notable for an increased level of serum IL-6 and serum IgG4. Histopathological examination showed a diffused dense nodular infiltration of “nude” epithelioid histiocytes with infiltration of minimal lymphocytes and plasm cells around the epithelioid nodules. Immunohistochemistry identified nodular histiocytes being stained strongly positive for S-100 and CD68 but negative for CD1a. ...
Source: The American Journal of Dermatopathology - December 24, 2020 Category: Pathology Tags: Extraordinary Case Report Source Type: research

Asymptomatic, Red-Brown Macules Symmetrically Distributed on Trunk and Arms of Adult Male: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - December 24, 2020 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

Left Ear Nodule: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - December 24, 2020 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research

Nonhealing Right Lower Leg Ulcer: Challenge
No abstract available (Source: The American Journal of Dermatopathology)
Source: The American Journal of Dermatopathology - December 24, 2020 Category: Pathology Tags: Clinical Pathologic Challenge Source Type: research