American Journal of Dermatopathology最新文献

Abstract: Several cutaneous neurovascular stromal lesions are clinically and pathologically ill-defined entities. They are known by different nomenclatures, often unrecognized, misinterpreted, and confused with other skin lesions. Reports have documented cases of palmar and oral lesions in both children and adults. There is uncertainty regarding their true prevalence, clinicopathologic characteristics, and classification. Our aim is to highlight the salient histopathologic, histochemical, and immunohistochemical features of acral nodular tumors showing perineuriomatous differentiation. We found 3 teenagers (0.2%) [2 females, 1 male, average age: 13 years] with hand nodules out of 1331 patients with cutaneous and oral polypoid lesions. They were isolated, asymptomatic, nontraumatic, subcentimetric, palmar, digital nodules with an average duration of 5 years. They demonstrated dermal-based anomalous growths composed of thick tortuous neurovascular bundles and collagenous fibrovascular stroma. Masson trichome demarcated micronodular and plexiform neurovascular bundles showing concentric onion-bulb whorls ensheathed in collagenous fibrovascular stroma. Elastic fibers were absent. Alcian blue demonstrated intraneural mucinous alteration and loose interstitial myxoid mesenchyme. CD31, ERG, and smooth muscle actin highlighted small intraneural capillary-sized, and larger venous and arteriolar interstitial vasculatures. CD34 decorated the interstitial mesenchyme. S100, SOX10, and neurofilament revealed sparse neural components, whereas EMA and GLUT1 highlighted prominent perineurial components within the neurovascular bundles and onion-bulb micronodules. The findings suggest that cutaneous intraneural pseudoperineurioma nodules may represent a distinct clinicopathologic entity among traumatic neuromas, resembling cutaneous intraneural perineurioma. Further validation studies are necessary because of the small size of the case series and the lack of molecular genetic studies.

Introduction: Leprosy is a neglected infectious disease caused by Mycobacterium leprae and Mycobacterium lepromatosis and remains a public health challenge in tropical regions. Therefore, the development of technological tools such as machine learning (ML) offers an opportunity to innovate strategies for improving the diagnosis of this complex disease.

Objective: To validate the utility of different ML models for the histopathological diagnosis of Hansen disease.

Methodology: An observational study was conducted where 55 H&E-stained tissue slides from leprosy patients and 51 healthy skin controls were analyzed using microphotographs captured at various magnifications. These images were categorized based on histopathological findings and processed using the Cross-Industry Standard Process for Data Mining methodology for designing and training ML models. Five types of ML models were evaluated using standard metrics such as accuracy, sensitivity, and specificity, emphasizing data normalization as a fundamental step in optimizing model performance.

Results: The artificial neural network (ANN) model demonstrated an accuracy of 70%, sensitivity of 74%, and specificity of 65%, demonstrating its ability to identify leprosy cases with moderate precision. The receiver operating characteristic curve of the ANN model showed an area under the curve of 0.71. Conversely, models such as decision trees, logistic regression, and random forests showed similar accuracy results but with slightly lower sensitivity, potentially indicating a higher risk of false negatives in detecting leprosy-positive cases.

Conclusion: The ANN model emerges as a promising alternative for leprosy detection. However, further refinement of these models is necessary to enhance their adaptability across different clinical settings and participation in patient care.

Abstract: Hidradenocarcinoma (HAC) is a rare malignant neoplasm originating from eccrine sweat glands, often presenting diagnostic challenges because of its resemblance to other malignancies, particularly breast cancer when occurring in the chest region. This report describes 2 cases of HAC with axillary lymph node metastasis, both initially misinterpreted clinically. The first case involved a 63-year-old woman with a sternal mass, near the right breast, initially suspected to be a sebaceous cyst. Histologic examination revealed a solid-cystic epithelial tumor with features suggestive of HAC, confirmed by immunohistochemical analysis. The second case concerned an 81-year-old woman with a subcutaneous growth in the sternal area, also diagnosed as HAC after histopathologic and immunohistochemical assessment. Both cases demonstrated strong estrogen receptor positivity, leading to the recommendation of hormonal therapy. A systematic review of the literature identified 21 similar cases of HAC in the chest wall, highlighting the diagnostic complexities and the potential for these tumors to mimic breast carcinoma. This review underscores the need for careful histologic and immunohistochemical evaluation to differentiate HAC from other malignancies, particularly in the breast region. Given the rare and the potential aggressive nature of HAC, early and accurate diagnosis is crucial for guiding appropriate therapeutic strategies and improving patient outcomes.

Abstract: Primary cutaneous anaplastic large cell lymphoma (pcALCL) is a CD30 + lymphoproliferative disorder with generally favorable outcomes and infrequent extracutaneous spread, usually limited to local lymph nodes. However, there may be extensive histologic overlap with more aggressive CD30 + lymphomas, such as large cell transformation of mycosis fungoides or secondary skin involvement by anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma. Definitive diagnosis relies on clinicopathologic correlation. We report on a 26-year-old woman who presented to our institution with progressive lower extremity wounds for several months, previously treated with antibiotics and vacuum-assisted closure dressings. Consultation with dermatology and 2 separate biopsies eventually led to the diagnosis of pcALCL. Subsequent imaging revealed stage IV disease with innumerable intensely fluorodeoxyglucose (FDG)-avid subcutaneous, intramuscular, and visceral foci, but paucity of lymph node involvement. The patient's condition deteriorated, and she died during her hospitalization. This case reviews the clinicopathologic findings of pcALCL, emphasizes the importance of clinicopathologic correlation in differentiating between CD30 + lymphoproliferative disorders, highlights the extremely rare phenomenon of systemic intramuscular and visceral disseminated disease occurring in pcALCL, and discusses implications for prognosis.

Abstract: Peripheral nerve sheath tumors can include neurofibroma, schwannoma, and perineurioma, with hybrid nerve sheath tumor (HNST) being rare. We describe 3 HNST cases with epithelioid schwannoma and neurofibroma features, an uncommon manifestation of hybrid schwannoma/neurofibroma. The 3 cases involved the upper back, forearm, and thigh. Histopathologically, the tumors were located in the subcutis or dermis and subcutis. The epithelioid schwannoma component showed nests/cords of epithelioid cells with round nuclei and abundant cytoplasm. In contrast, the neurofibroma component showed spindle cell proliferation within myxoid stroma. The 3 cases showed variable proportions of both components. Immunohistochemically, the epithelioid schwannoma components were positive for S100 protein and negative for CD34, whereas the neurofibroma component showed partial S100 immunoreactivity and contained abundant CD34-positive cells with a fingerprint pattern. Epithelial membrane antigen and GLUT1 revealed the perineurial capsules. In conclusion, our cases expand the morphologic spectrum of HNST and underscore the importance of recognizing this variant.

Abstract: Cutaneous vasculitis, either as a single organ or part of systemic vasculitis, can take various forms. Granulomatosis with polyangiitis (GPA) is characterized by necrotizing granulomatous inflammation in the respiratory tract and vasculitis affecting small- to medium-sized blood vessels. Skin-limited GPA, an uncommon presentation, poses diagnostic challenges and may result in delayed diagnosis. We describe a 32-year-old man with painful ulcers and black eschars on both lower limbs, evolving from purpura. Despite lacking typical anti neutrophil cytoplasmic antibodies and systemic involvement, histopathology revealed granulomatous vasculitis. Treatment with prednisolone and methotrexate led to complete symptom resolution within 8 months. Skin-limited GPA, often without anti neutrophil cytoplasmic antibody positivity, warrants clinical suspicion, early intervention, and increased awareness to enhance patient outcomes.

Abstract: The diagnosis of systemic amyloidosis is decided through histologic materials from biopsy from different organs. This is a retrospective study from the institutional database of our hospital and consisted of patients to being judged to need skin biopsy for the purpose of diagnosing systemic amyloidosis visiting dermatology between April 2005 and August 2022. A total of 30 patients underwent the skin biopsy of dermis and fatty tissue on abdominal wall without rash and a total of 36 specimens were obtained. A total of 14 of these specimens showed amyloid deposition histologically. Among the 14 specimens, amyloid immunoglobin light chain amyloidosis in 8 samples (57.1%) was the most diagnosed, the others being wild-type amyloid transthyretin amyloidosis in 5 samples (35.8%) and amyloid A amyloidosis in 1 sample (7.1%). The skin biopsy has an 87.5% (14 of 16) sensitivity and 100% (20 of 20) specificity, with 12.5% (2 of 16) false negatives and 0% (0 of 20) false positives in diagnosis of systemic amyloidosis. Skin biopsy from normal abdominal wall skin to evaluate dermis and fatty tissue is a safe, sensitive, and specific procedure to the diagnosis of systemic amyloidosis.