American Journal of Dermatopathology最新文献

Abstract: Ambiguous melanocytic lesions/tumors (AMLs) can be simply described as melanocytic neoplasms that cannot be differentiated as either a melanoma or a nevus. Preferentially expressed antigen in melanoma (PRAME) is a novel antibody that can help differentiate between nevi and melanomas. However, its usefulness remains controversial in AMLs. The aim of this study was to demonstrate the importance of PRAME and diagnostic auxiliary antibodies (Ki-67, p16, HMB-45) in the diagnosis of melanocytic lesions, especially in AMLs. This study included 52 ambiguous melanocytic lesions, 40 nevi, and 40 melanomas. All immunohistochemical studies were performed automatically using the Universal Alkaline Phosphatase Red Detection Kit. Different analytic approaches were used for each antibody based on the literature. Statistically, the multinomial forward stepwise elimination logistic regression analysis was used to create a statistical model to predict the diagnosis of melanocytic lesions based on clinical, morphological, and immunohistochemical data. PRAME positivity was very strong and diffuse in the melanoma group and statistically significantly higher than that of the AML and nevus groups. There was no statistically significant difference between the nevus and AML groups. The Ki-67 proliferation index and HMB-45 staining pattern provided valuable indications for distinguishing between these 3 groups. The P16 antibody was limited in supporting the differential diagnosis. Our statistical model showed that a high mitosis count, central pagetoid spread, and PRAME positivity increased the probability of melanoma against an AML diagnosis. This study showed the advantages of evaluating the PRAME antibody together with morphological features and other immunohistochemical markers (Ki-67 and HMB-45) in the differential diagnosis of melanocytic lesions.

Abstract: Microsatellitosis is well established as a prognostic factor in malignant melanoma. Its identification leads to subsequent upstaging with implications for further management. We describe 6 cases in which immunohistochemical staining for PReferentially expressed Antigen in MElanoma facilitated detection of small foci of micrometastasis on scanning magnification, which may be potentially missed in routine sections.

Abstract: Dermatofibrosarcoma protuberans (DFSP) is a neoplasm of intermediate malignancy with high local recurrence rates. The sclerosing variant is characterized by the presence of sclerotic areas in more than 50% of tumors and is rarely reported. In this report, we describe a case of sclerosing DFSP with areas histopathologically resembling sclerotic fibroma, where the initial biopsy tissue presented a diagnostic challenge. A 77-year-old man presented with a 2-cm firm, erythematous nodule on the chest. A punch biopsy revealed plywood-like sclerosis and spindle cells with a vaguely storiform pattern. The tumor cells were positive for CD34. Sclerotic fibroma and DFSP were considered differential diagnoses. Subsequent excisional biopsy revealed that the tumor comprised 3 different histopathological areas: classic DFSP, sclerotic fibroma-like, and giant cell fibroblastoma-like. This report highlights the importance of reevaluating the clinical context and excision for further characterization.

Abstract: Coma blisters are epidermal and subepidermal bullous lesions that can arise throughout the body after a prolonged impairment of consciousness. Coma blister-like lesions have been well-documented in adults after barbiturate-induced intoxication. More recently, other drugs and substances have been associated with the development of these bullae, which has broadened the scope of medications that put patients at risk of developing coma blister-like lesions. We present a unique case of a noncomatose patient who developed coma blister-like lesions after trazodone misuse. This case illustrates the need to further investigate the mechanism behind drug-induced coma bullae-like lesions so that clinicians can better identify and discontinue drugs that precipitate such lesions.

Abstract: We present the case of a 61-year-old male patient with a history of intracranial IDH-wildtype glioblastoma with an isolated cutaneous metastasis within the previous surgical site scar. The cytomorphology of the cutaneous deposits was reminiscent of metastatic melanoma, which is a differential diagnostic pitfall. The tumor molecular characteristics are described, as these have become essential diagnostic criteria for many central nervous system tumors, along with a discussion of the role of immunohistochemical markers and potential pitfalls in the differential diagnosis of melanoma and poorly differentiated carcinoma. We discuss the biology of metastatic glioblastoma and provide a focused literature review of previous glioblastomas with tumor cell seeding within prior surgical scars.