A Case of Superficial Papular Neuroma: A Rare Neural Neoplasm.

ABSTRACT: A case of 67-year-old male patient with superficial papular neuroma (SPN) on the occiput is reported. This is the second report of SPN and the first with clinical images. Histologically, in the superficial dermis and periadnexa, the specimen exhibits a nodule of bland spindle cells with an S-shaped and spindle nucleus, surrounded by eosinophilic collagen fibers and scattered mast cells, which forms focally peripheral nerve-like structures. Lichen simplex chronicus-like changes are observed. Immunostaining result revealed that the tumor cells are positive for S-100, neurofilament, collagen IV, and CD34 but negative for Melan A, epithelial membrane antigen, and glial fibrillary acidic protein. Histological differential diagnosis includes prurigo nodularis, neurotized nevus, benign peripheral nerve sheath tumor, such as neurofibroma or schwannoma, a type of neuroma, such as traumatic neuroma, mucosal neuroma, and palisaded encapsulated neuroma, or a type of neural hamartoma. A careful histological investigation will enable dermatopathologists to make a diagnosis of SPN.

Alopecia - New building blocks.

Hair loss is devastating to the patient, but the diagnosis and treatment of alopecia are also difficult for primary care providers and even dermatologists. Given recent advances in the field, there has never been a more pressing time to reevaluate and improve upon the significant clinical skills needed to accurately diagnose and treat our patients with hair loss. This CME activity on alopecia is designed to (1) educate dermatologists in a simple, succinct fashion on the identification of, and the distinction between, the diverse types of hair loss and (2) discuss how to manage them.

Superficial temporal artery pseudoaneurysm: Report of two cases and review.

Superficial temporal artery pseudoaneurysm is a rare complication of arterial injury developing on the forehead following blunt trauma. There is little written on this entity in the dermatopathology literature. We describe two cases of superficial temporal artery pseudoaneurysm in two men aged 53 and 25 years, one of whom had a recent history of head trauma. This report reviews the classic histopathologic findings of STA pseudoaneurysm and highlights ways to distinguish it from other entities in the differential diagnosis.

Sebaceous gland atrophy in seborrheic dermatitis of the scalp; a pilot study.

BACKGROUND: Sebaceous gland (SG) atrophy is well-documented in scalp lesions of psoriasis and has been considered as an important clue to psoriatic alopecia. However, its specificity for psoriasis has been questioned over the years. We hypothesize that SG atrophy is not specific for psoriasis and looked for its presence in biopsies of seborrheic dermatitis of the scalp. METHODS: We conducted a retrospective study of biopsy specimens of clinically suspected and histopathologically proven seborrheic dermatitis of the scalp for changes in SGs between January 1, 2014 and August 6, 2021. RESULTS: SGs lobules were smaller and narrower in five of the six cases of seborrheic dermatitis, and SG atrophy was present in four out of six cases. CONCLUSIONS: SG atrophy is observed in seborrheic dermatitis and is not specific for psoriasis or psoriatic alopecia.

Early Erythema Migrans: Do Not Count on Plasma Cells.

ABSTRACT: Three hundred thousand new cases of Lyme disease are diagnosed annually in the United States. The earliest manifestation of the disease, erythema migrans, occurs earlier than serologic conversion, and skin biopsies can be very helpful in suggesting the diagnosis. Histopathologic findings vary depending on where in the lesion the specimen is taken, but typically consist of a superficial and deep perivascular and interstitial lymphocytic infiltrate with eosinophils centrally and with histiocytes and plasma cells at the periphery. Rare cases with interstitial histiocytes and rare-to-sparse plasma cells exist. We present a 67-year-old man whose skin biopsy, taken on day 2 of his eruption, demonstrated a subtle perivascular and interstitial infiltrate of histiocytes without plasma cells. Dermatopathologists need to be aware of this pattern and consider the diagnosis of erythema migrans, despite negative initial serologic testing.

Exogenous Ochronosis as an Elastotic Disease: A Light-Microscopic Approach.

BACKGROUND: Exogenous ochronosis (EO) is a deposition disease associated with application of hydroquinone-containing preparations. Characteristic ochronotic bodies (OBs) arise from endogenous connective tissues, most often reported as collagen. We highlight a significant role for elastic fibers as a precursor tissue. OBJECTIVE: To evaluate elastic tissue pathology in EO, specifically as it relates a precursor role in ochronotic body formation. METHODS: In this retrospective observational study, a literature review using PubMed/MEDLINE database was conducted to ascertain the most commonly ascribed precursor connective tissue. Eleven histopathologic cases of EO were identified. Patient demographics and clinical characteristics were recorded. Slides were reviewed for the presence and grade of solar elastosis (SE), the relationship of OBs to elastotic material, the presence of elastotic fibers transitioning to OBs, and positivity of bodies with Verhoeff-van Gieson elastic tissue stain. RESULTS: Elastic fibers are uncommonly reported as the major precursor tissue of OBs. SE was uniformly present in our cases, and the majority demonstrated heavy/high-grade elastosis. Elastotic fibers transitioning to OBs were observed in all cases, and the bodies demonstrated Verhoeff-van Gieson positivity. LIMITATIONS: Small sample size. CONCLUSIONS: Ochronotic body formation is associated with SE, and bodies appear to arise from damaged elastic fibers.

Amelanotic melanoma arising within a lesion of disseminated superficial actinic porokeratosis: An unusual presentation leading to a novel therapeutic approach.

Disseminated superficial actinic porokeratosis (DSAP) is the most common variant of porokeratosis with a potential for malignant transformation. Its association with malignant melanoma, however, is exceedingly rare. Treatment of DSAP is often ineffective. We report a unique case of amelanotic melanoma arising within a lesion of DSAP. The melanoma was managed surgically, and her DSAP were treated successfully with a novel approach utilizing 5-fluorouracil chemowraps.

Histologic features of chronic cutaneous lupus erythematosus of the scalp using horizontal sectioning: Emphasis on follicular findings.

BACKGROUND: Chronic cutaneous lupus erythematosus (CCLE) often affects the scalp resulting in scarring alopecia. While histopathologic findings of CCLE have been well described, there is little written on the morphologic changes to the hair follicles in this condition. OBJECTIVE: We aim to determine the histopathologic findings of hair follicles in CCLE of the scalp. METHODS: We conducted a retrospective study of 33 transversely sectioned skin biopsy specimens of CCLE of the scalp at the Skin Pathology Laboratory at Boston University between April 2005 and March 2015. RESULTS: New findings include basaloid follicular epithelium lacking hair follicles at deep levels, follicular miniaturization, increased catagen/telogen hair follicles, and pigment casts. Two histopathologic patterns could be discerned, an alopecia areatalike pattern and a lichen planopilarislike pattern. LIMITATIONS: Generalizability of a single-center experience may be limited. CONCLUSION: Follicular findings in CCLE of the scalp are reported. We hypothesize that the basaloid aggregates are remnants of hair follicles that are no longer actively cycling.

Permanent alopecia in patients with breast cancer after taxane chemotherapy and adjuvant hormonal therapy: Clinicopathologic findings in a cohort of 10 patients.

BACKGROUND: Anagen effluvium with reversible scalp alopecia is a known side effect of chemotherapy. However, there are an increasing number of reports in the literature documenting permanent alopecia in patients treated with taxanes. OBJECTIVE: We sought to describe the clinicopathologic features in breast cancer patients who underwent treatment with taxanes and adjuvant hormonal chemotherapy. METHODS: We reviewed the clinical and histopathologic information of a cohort of 10 patients treated with taxanes and adjuvant hormonal chemotherapy. RESULTS: We have observed 3 types of clinical patterns of alopecia (types A, B, and C), and have validated the histopathologic features showing alopecia areata-like and female pattern hair loss. LIMITATIONS: The study was based on a small sample size and retrospective retrieval of clinical information and histopathologic review of posttreatment slides. CONCLUSIONS: We hypothesize a clinicopathologic model of hair follicle cycle disruption in response to the chemoinflammatory and hormonal insults to the hair follicles resulting in permanent alopecia. Clinicopathologic correlation is paramount to the understanding of the morphobiologic pathways in chemotherapy-induced alopecia caused by taxanes and adjuvant hormonal treatment.

Cutaneous involvement in luteinized thecomas with sclerosing peritonitis (LTSP)-A new finding in a rare syndrome.

Luteinized thecomas with sclerosing peritonitis (LTSP) is a rare disease characterized by ovarian luteinized thecomas and associated fibrosing peritonitis. Cutaneous involvement has never been reported. We report a case of classical LTSP with skin involvement, outlining the clinical and histopathologic features of this novel presentation of a rare syndrome.

Benign and malignant hybrid adnexal tumors in a patient with epidermodysplasia verruciformis.

Epidermodysplasia verruciformis (EV) is a genodermatosis characterized by overgrowth of flat warts, pityriasis versicolor-like lesions and an increased propensity for developing cutaneous squamous cell carcinomas due to abnormal susceptibility to infection with beta-human papilloma viruses. Adnexal tumors are not typically associated with EV. Here we report a spectrum of hybrid adnexal tumors with divergent eccrine and folliculosebaceous differentiation, and cytologic features ranging from benign to frankly atypical, in a patient with inherited EV.

Hyperkeratotic and hypertrophic lichen nitidus.

Lichen nitidus typically presents as shiny pin-head sized papules on the trunk and extremities, often affecting children and young adults. In this prototypical form, it rarely presents a diagnostic challenge being characterized by distinctive clinical and histopathologic findings. We describe a rare variant of lichen nitidus, which we term "hyperkeratotic and hypertrophic lichen nitidus."

Dermatopathologic manifestations of intravenous drug use.

BACKGROUND: The rate of intravenous drug use (IVDU) has been increasing nationally; however, cutaneous manifestations of IVDU have infrequently been investigated. We report a series of the clinicopathological correlation of IVDU in the skin. METHODS: A search of surgical pathology files between the years 2000 and 2014 was performed for cutaneous specimens from patients with a reported history of IVDU for which the histopathological findings could not be attributed to another etiology. Ten cases for which slides were available were included in the study. RESULTS: Patients had an average age of 39.7 years and had active or recent history of IVDU. Clinical impressions included ulcer, granulomatous dermatitis, vasculitis, pyoderma gangrenosum and hyperpigmentation at injection sites. Histopathology revealed leukocytoclastic vasculitis (n = 2), dermal pigment deposition (n = 3), non-specific ulceration/scarring (n = 4) and necrobiosis lipoidica-like dermatitis (n = 1). No infectious etiology or polarizable foreign material was identified in any case. CONCLUSIONS: Cutaneous manifestations of IVDU should be considered in the differential as an etiology for dermatopathologic findings in high-risk patients. We report histopathological findings beyond the scope of those most commonly associated with IVDU. We aim to raise awareness of the cutaneous manifestations of IVDU to improve clinicopathological correlation and patient management in light of the ongoing epidemic.

Incidental simultaneous finding of intravascular histiocytosis and reactive angioendotheliomatosis: a case report.

Reactive angioendotheliomatosis (RAE) is a rare cutaneous vascular disorder characterized by intravascular hyperplasia of endothelial cells, sometimes with a vascular proliferation. Intravascular histiocytosis (IH) is a similar vascular disorder characterized by the presence of dilated vessels containing aggregates of mononuclear histiocytes (macrophages) within their lumina. Although their pathogenesis remains uncertain, there has been speculation about the possible relationship between IH and RAE. We report a case of coexistence of RAE and IH in a patient who underwent a wide reexcision of a metastatic malignant melanoma. The excision specimen did not show any residual melanoma but exhibited an intravascular collection of CD-68-positive histiocytes admixed with CD-31-positive endothelial cells and fibrin surrounded by D2-40-positive vascular wall. The presence of intravascular cells initially raised concern of intravascular invasion by melanoma. As there was no clinical lesion and immunohistochemical stains for melanocytic makers were negative, we interpret this as an incidental finding. Knowledge of this benign vascular disorder is important because the histologic changes may be mistaken for intravascular invasion of a malignant neoplasm.

Pseudocarcinomatous hyperplasia involving the ear from gout: a diagnostic pitfall.

The ear is a characteristic location for deposition of uric acid in patients with gout. Pseudocarcinomatous hyperplasia has not been described in this location. We report three patients with tophaceous gout on the ear whose biopsies exhibited epidermal hyperplasia mimicking squamous cell carcinoma, in order to call attention to this potential diagnostic pitfall.

Extraocular sebaceous carcinoma in situ: report of three cases and review of the literature.

Extraocular sebaceous carcinoma is a rare neoplasm. Purely in situ extraocular sebaceous carcinoma is extremely rare and somewhat controversial. Review of the literature reveals only three reported cases, two of which involved the head and neck and one the arm. The ones on the head and neck arose in association with an actinic keratosis. We report three cases of extraocular sebaceous carcinoma in situ and describe the first report of immunoperoxidase screening for mismatch repair proteins in such tumors.

Quantification of mast cells in central centrifugal cicatricial alopecia.

Background: Mast cells (MCs) have recently been implicated in lymphocytic scarring alopecias, which may share a common pathogenesis. MCs in central centrifugal cicatricial alopecia (CCCA) have not been studied. Objective: We looked for the presence of MCs in CCCA using 2 different stains to see if their numbers correlated with the number of hair follicles, the degree of inflammation and perifollicular fibrosis, disease duration and severity, and patient symptoms. Methods: We performed a retrospective review of biopsies of patients diagnosed with CCCA, tabulated MC counts and correlated them with histopathologic and clinical findings. Results: MC counts were significantly greater using immunoperoxidase staining with CD117 than Giemsa stain, and more were present when the isthmus level was included with the infundibulum. MC counts with CD117 immunostain significantly correlated with the degree of inflammation. MC counts with both stains were significantly associated with the degree of fibrosis independently and after controlling for other factors. Limitations: The study was limited by insufficient tissue remaining in a small number of the transversely cut blocks. Conclusion: Our findings may have therapeutic implications for CCCA and other types of lymphocytic scarring alopecia.