Incipient Intracholecystic Papillary Neoplasm of the Gallbladder Without Dysplasia.

Intracholecystic papillary neoplasm (ICPN) of the gallbladder is a rare tumor described as a mucosal exophytic neoplastic lesion that projects into the gallbladder lumen. In regards to the size, lesions that did not make the arbitrary 1cm cutoff are described as "incipient" ICPN. Not much is known about these incipient ICPNs, as they are often excluded in ICPN studies, given the attempted adherence to the traditional 1cm cutoff.

Trigeminal trophic syndrome: A systematic review.

Objectives: To systematically report and document Trigeminal Trophic Syndrome (TTS), characterize its clinical presentation, diagnostic tests performed, outline management strategies, outcomes; and highlight the role of otolaryngologists in the tissue diagnosis of this rare syndrome.

Data Sources: PubMed/Medline, Scopus, and Cochrane databases.

Review Methods: PubMed/Medline, Scopus, and Cochrane databases were systematically reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify all cases of TTS published with an English translation from inception to December 2020.

Primary Cutaneous Ewing Sarcoma of the Scalp With Metastasis to the Lung: An Unusual Manifestation During Pregnancy.

A 32-year-old G2P1L1 (5 months pregnant) woman presented with a 3-month history of a slow-growing cystic lesion on her scalp vertex. Similar lesions in the exact location were excised twice in the past with a diagnosis of trichilemmal carcinoma (TC). A biopsy of the scalp lesion showed morphology and immunoprofile consistent with previously diagnosed TC.

Isolated leukemia cutis as extramedullary relapse of acute myeloid leukemia.

Acute myeloid leukemia (AML) arises from clonal expansion of malignant hematopoietic precursor cells in the bone marrow. In rare instances, AML can recur with prominent extramedullary manifestations (i.e.

Histopathologic features of inverse psoriasis.

Background: Inverse psoriasis represents a less commonly described form of psoriasis in intertriginous areas. The pathologic findings of inverse psoriasis are typically grouped in with those of plaque psoriasis, as the histopathologic features specific to inverse psoriasis have not received significant investigation.

Methods: A single institution, retrospective cohort study was performed to review biopsy slides for psoriasis occurring in typical intertriginous areas.

A Case of Primary Myelofibrosis With Transformation to Leukemia Cutis.

We report an extraordinary case of primary myelofibrosis with transformation to leukemia cutis. A 64-year-old Caucasian man with a history of JAK2-positive primary myelofibrosis presented with erythematous papulonodules on his right lower extremity. A punch biopsy revealed a normal epidermis with an underlying diffuse dermal infiltrate composed of medium-to-large-sized myeloid cells and leukocytes.

Chronic myeloid leukemia-leukemia cutis mimicking a neutrophilic panniculitis-like leukemia cutis: Report of a rare case.

While drug-induced panniculitis is not uncommon in chronic myeloid leukemia (CML) patients on tyrosine kinase inhibitor therapy, it is rare for CML to initially present as a leukemic panniculitis. We present the case of a 45-year-old male with no relevant prior medical history presenting with 6 months of migratory nodules, 2 months of drenching night sweats, and a 20 pound weight loss. Physical examination showed firm subcutaneous nodules with overlying ecchymoses present on the right lateral thigh and left lower back.

Multifocal Langerhans Cell Histiocytosis: A Unique Presentation of Eosinophilic Granuloma with Intracranial Extension, Massive Lymphadenopathy, and Epstein-Barr Viral Infection in an Adolescent Female.

We report the case of an otherwise healthy 17-year-old female who presented for surgical removal of an enlarging "atypical cyst" on her scalp. During subtotal excision, only friable serosanguinous translucent ribbons of tissue were found. A histopathologic diagnosis of Langerhans cell histiocytosis (LCH) was rendered and imaging studies revealed extradural invasion of the tumor.

The Role of IL-13, IL-15 and Granulysin in the Pathogenesis of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis.

Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) are Severe Cutaneous Adverse Reactions (SCARS) characterized by fever and mucocutaneous lesions leading to necrosis and sloughing of the epidermis. Conjunctival lesions are reported in 85% of patients. The pathogenesis of SJS/TEN/SCARS is not completely understood.

A Rare Case of Lichen Planus-Like Atopic Dermatitis Involving the Hands.

Lichen planus-like atopic dermatitis clinically mimics lichen planus and can pose a diagnostic challenge. We report a case of a 55-year-old African American woman who developed intensely pruritic papules and plaques on bilateral hands. Histological examination demonstrated acute spongiotic dermatitis with lymphocyte exocytosis into the epidermis.

Pembrolizumab-Induced Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis in a Patient With Metastatic Cervical Squamous Cell Carcinoma: A Case Report.

We present a rare case of a pembrolizumab-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). A 55-year-old woman with a history of metastatic cervical squamous cell carcinoma presented with a widespread mucocutaneous rash. Seventeen days after receiving her first cycle of pembrolizumab, she presented with fever, difficulty breathing, watery eyes, and painful oral ulcers.

The Conundrum of Diagnosing Cutaneous Composite Lymphoma in the Molecular Age.

Introduction: Cutaneous composite lymphoma (CCL) is extremely rare. When 2 potentially distinct lymphoid lesions occur at one skin site, distinguishing between one neoplastic clone and a secondary reactionary lymphoid response versus a second neoplasm is difficult. In this study, we describe a unique case of CCL along with a review of reported cases in literature to identify clues and discuss issues that are relevant to the diagnosis of CCL.

Is melanocyte density our last hope? Comparison of histologic features of photodamaged skin and melanoma in situ after staged surgical excision with concurrent scouting biopsies.

Differentiating melanocytic hyperplasia (MH) on photodamaged skin from junctional lentiginous melanocytic proliferations (JLMP), early evolving melanoma in situ (MIS), or the periphery of a lesion of MIS on staged excision can be challenging. Although previous cross-sectional studies have elucidated important criteria for distinguishing MH on photodamaged skin from more concerning lesions, this study highlights a technique to treat JLMP and MIS with staged mapped excision and baseline scouting biopsies of adjacent nonlesional photodamaged skin to assist in determination of surgical margin clearance. Additionally, we compare the lesional and photodamaged control biopsies from the same patient to evaluate relevant histologic criteria that may be used to distinguish MH in photodamaged skin from JLMP/MIS, while minimizing confounding factors.

Gene expression profiling of lichenoid dermatitis immune-related adverse event from immune checkpoint inhibitors reveals increased CD14 and CD16 monocytes driving an innate immune response.

Background: Cancer patients receiving antibodies abrogating immune checkpoint pathways may develop a diverse array of immune-related adverse events (irAEs), of which lichenoid dermatitis (LD) is the most common. The mechanism driving the emergence of these irAEs remain understudied, underscoring a critical need to determine the unique gene expression profiles and immune composition in LD-irAE.

Methods: LD-irAE (n = 3) and benign lichenoid keratosis (BLK) control (n = 3) were profiled with NanoString nCounter PanCancer Immune Profiling Panel interrogating the mRNA levels of 770 genes.

Clonal highlights: Clonal seborrheic keratoses often demonstrates p16 expression.

Background: At times, distinguishing Bowen disease (BD) and benign seborrheic keratosis (SK) is histologically challenging, especially when SK shows clonal features (clonal seborrheic keratosis [CSK]). While p16 is often reported as positive in BD and negative in SK, p16 expression in CSK is rarely studied. Here we investigate p16 immunohistochemistry in CSK, SK, and BD.

Perianal extramammary Paget disease treated with topical imiquimod and oral cimetidine.

Extramammary Paget disease (EMPD) is a rare intraepithelial adenocarcinoma. The current mainstay of treatment is wide local excision. We present the case of a 56-year-old woman with perianal EMPD that recurred 4 years after initial treatment with wide local excision with Mohs micrographic surgery tissue processing of marginal tissue.

Cutaneous Cytomegalovirus Infection in an Immunocompetent Patient: Innocent Bystander or Culprit?

We present a rare case of cutaneous cytomegalovirus (CMV) infection in a nonimmunocompromised patient. A 74-year-old woman with a history of diabetes presented with an ulcer on the right lateral tibia that occurred at the site of a nerve core biopsy. Subsequent biopsy of the ulcer edge showed granulation tissue with neutrophilic inflammation.

The microenvironment in primary cutaneous melanoma with associated spontaneous tumor regression: evaluation for T-regulatory cells and the presence of an immunosuppressive microenvironment.

Spontaneous tumor regression, regression in the absence of therapeutic intervention, can be identified histologically in over 25% of primary cutaneous melanomas at initial diagnosis. A unique subset of T lymphocytes found in areas of regression can be histologically distinguished from tumor-infiltrating T lymphocytes (TIL) found in areas of tumor progression. We call this unique subset of T lymphocytes regression-associated T lymphocytes (RATs).

Changing Dermatopathology Protocols for Processing Small Skin Biopsies: Decreases in Slide Quantity Does Not Affect Patient Care and Allows for Optimal Efficiency.

In dermatopathology, no standard protocol exists for processing small biopsy specimens. In our original protocol, 2 routine initial slides per biopsy were prepared. For 1003 biopsies, we noted how often the second slide helped in diagnosis or eliminated the need for additional deeper sections.

BRAF inhibitor therapy-associated melanocytic lesions lack the BRAF V600E mutation and show increased levels of cyclin D1 expression.

Newly appearing or changing melanocytic lesions (MLs) are a recently reported toxicity of BRAF inhibitor (BRAFi) therapy. Morphologically, MLs associated with BRAFi therapy (BRAFi-MLs) may demonstrate alarming features of melanoma with an epithelioid cell phenotype with notable cytologic atypia. We sought to characterize the clinicopathological and molecular features of BRAFi-MLs.

A Rare Case of a 15-Year-Old Boy with Two Accessory Nipples: One in the Forearm and One in the Milk Line.

A 15-year-old male presented for evaluation of a volar forearm mass that he noticed four years before. The mass was not painful and his main concern was cosmesis. The mass was two centimeters in diameter with a pinpoint central sinus and scant drainage.