Nonsclerotic Lichen Sclerosus: Definition of a Concept and Pathologic Description.

OBJECTIVE: Nonsclerotic lichen sclerosus (NSLS) refers to the clinicopathologic situation of examination findings consistent with lichen sclerosus (LS) but without dermal sclerosis on microscopy. This review aims to describe the features of NSLS and provide a classification framework. METHODS: The International Society of the Study of Vulvovaginal Diseases tasked the Difficult Pathologic Diagnoses Committee with development of consensus documents for conditions with problematic histopathology. The Difficult Pathologic Diagnoses Committee reviewed the literature on NSLS and formulated descriptions and diagnostic criteria, then approved by the International Society of the Study of Vulvovaginal Diseases membership. RESULTS: Nonsclerotic LS may be categorized into 4 histopathologic subtypes: lichenoid dermatitis, hypertrophic lichenoid dermatitis, dermal fibrosis without acanthosis, and dermal fibrosis with acanthosis. Each has a pathologic differential diagnosis of 1 or more entities, so clinical correlation is required for final diagnosis of LS. There is no evidence to support a reliable association between absent sclerosis and clinical appearance, duration, or oncogenic potential of LS. CONCLUSIONS: Pathologists and clinicians should be familiar with the concept of NSLS and its implications for patient management. Use of the term "early LS" to indicate a lack of sclerosis in presumed LS should be abandoned. Clinical correlation is required to confirm LS from among the differential diagnoses.

A Rare Case of Monomorphic T-Cell Posttransplant Lymphoproliferative Disorder Presenting as Primary Cutaneous Anaplastic Large Cell Lymphoma, ALK Negative.

ABSTRACT: Posttransplant lymphoproliferative disorders are a serious complication of hematopoietic and solid organ transplants secondary to iatrogenic immunosuppression. Most cases present as B-cell proliferations which are often Epstein-Barr virus positive; however, ∼10% of cases are T/NK cell and are less commonly associated with Epstein-Barr virus. Of these, cutaneous T/NK-cell lymphomas are exceedingly rare. We report a case of a 69-year-old male, liver transplant recipient who presented with a tender, bright red papule on the left arm during his annual skin cancer screening. Histopathologic evaluation revealed pleomorphic cells with enlarged nuclei, vesicular chromatin, and frequent mitotic figures, intercalating through the dermis. The tumor formed single strands and small cords without epidermal involvement. A patchy mild mixed inflammatory infiltrate was associated with the tumor. Tumor cells were CD2(+), CD4(+), CD30(+), CD3(-), CD20(-), ALK-1(-), and EBER(-). Molecular studies revealed a monoclonal T-cell receptor gamma gene rearrangement by polymerase chain reaction (PCR); ALK gene rearrangement was negative by fluorescence in situ hybridization (FISH). Taken together, the findings were consistent with an ALK-negative anaplastic large cell lymphoma involving skin, which, given the history of liver transplant, qualified as a monomorphic T-cell posttransplant lymphoproliferative disorder. Follow-up imaging studies showed no evidence of systemic disease, supporting an interpretation of primary cutaneous anaplastic large cell lymphoma.

Cutaneous Actinomycosis of the Perineum in an Immunocompetent Man.

ABSTRACT: We present a case of primary cutaneous actinomycosis of unclear pathogenesis. A 30-year-old-man with no significant medical or surgical history presented to the emergency department with a 2-week history of a tender perineal mass. The patient denied trauma or perforating injury to the area. Examination of the area revealed an indurated, nonfluctuant, erythematous papulonodule located 2 cm from the anus. The lesion was unresponsive to oral and topical antibiotics and was therefore excised. The excision specimen revealed a dense mixed infiltrate partially filling the reticular dermis and extending into the subcutaneous fat. The infiltrate surrounded grains of basophilic material with an outer rim of eosinophilic radiating Splendore-Hoeppli material. Within the grains, filamentous bacteria were highlighted with Periodic acid-Schiff and Grocott's methenamine silver. The organisms were gram-positive and acid-fast negative. Given the clinical and histopathologic findings, actinomycosis was diagnosed. Two weeks later, the patient reported resolution of symptoms. The patient was lost to follow-up. This case highlights an unusual presentation of actinomycosis and the crucial role histopathology plays in diagnosis.

Diagnostic Criteria for Differentiated Vulvar Intraepithelial Neoplasia and Vulvar Aberrant Maturation.

OBJECTIVE: The aim of the study was to describe the features required for diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN) and vulvar aberrant maturation (VAM). MATERIALS AND METHODS: The International Society of the Study of Vulvovaginal Diseases tasked the difficult pathologic diagnoses committee to develop consensus recommendations for clinicopathologic diagnosis of vulvar lichen planus, lichen sclerosus, and dVIN. The dVIN subgroup reviewed the literature and formulated diagnostic criteria that were reviewed by the committee and then approved by the International Society of the Study of Vulvovaginal Diseases membership. RESULTS: Differentiated vulvar intraepithelial neoplasia is the immediate precursor of human papillomavirus (HPV)-independent vulvar squamous cell carcinoma and shows a spectrum of clinical and microscopic appearances, some overlapping with HPV-related neoplasia. The histopathologic definition of dVIN is basal atypia combined with negative or nonblock-positive p16 and basal overexpressed, aberrant negative, or wild-type p53. The most common pattern of dVIN is keratinizing with acanthosis, aberrant rete ridge pattern, and premature maturation. The morphologic spectrum of keratinizing dVIN includes hypertrophic, atrophic, acantholytic, and subtle forms. A few dVIN cases are nonkeratinizing, with basaloid cells replacing more than 60% of epithelium. Vulvar aberrant maturation is an umbrella term for lesions with aberrant maturation that arise out of lichenoid dermatitis and lack the basal atypia required for dVIN. CONCLUSIONS: Evaluation of women at risk for dVIN and VAM requires a collaborative approach by clinicians and pathologists experienced in vulvar disorders. Close surveillance of women with lichen sclerosus and use of these recommendations may assist in prevention of HPV-independent squamous cell carcinoma through detection and treatment of dVIN and VAM.

Vulvar Neoplasms, Benign and Malignant.

Cutaneous vulvar neoplasms are commonly encountered at gynecology visits, with 2% of women having a benign vulvar melanocytic nevus and 10% to 12% of nevi being vulvar. High-grade squamous intraepithelial lesions (vulvar intraepithelial neoplasia 2 or 3) occurs in 5 per 100,000 women, with increasing incidence in the past 30 years. The recognition of these lesions and differentiation between benign, premalignant, and malignant stages are crucial for adequate diagnosis, clinical monitoring, and treatment. The presentation, diagnosis, and management of benign and malignant vulvar proliferations are discussed with focus on practical aspects of clinical care.