American Journal of Dermatopathology最新文献

Abstract: Syphilis is a sexually transmitted disease that can present a wide variety of clinical and histopathological manifestations. We present the case of a 75-year-old patient with a persistent maculopapular rash on the trunk and extremities, in which the biopsy showed an exclusively perifollicular granulomatous infiltrate. In the immunohistochemical staining with anti- Treponema pallidum antibodies, spirochetes scattered within the perifollicular inflammatory infiltrate were identified. These findings together with the serological analysis allowed the diagnosis of secondary syphilis. Folliculotropic nonalopecic syphilis is rare, and the pathogenic mechanisms that cause this specific tropism are unknown. On the other hand, granulomatous inflammation is a pattern typically described in tertiary syphilis but also occasionally found in secondary syphilis. We present a case of secondary syphilis with the combination of both histopathological findings, an uncommon constellation for dermatopathologists to consider.

Abstract: Primary cutaneous spindle B-cell lymphoma is an uncommon subtype of cutaneous lymphoma characterized by a distinct spindled cytology of neoplastic B cells. Despite sharing clinical, histopathological, and phenotypical similarities with primary cutaneous follicle center lymphoma, an indolent form of B-cell lymphoma, it also exhibits certain features akin to primary cutaneous diffuse large B-cell lymphoma. Notably, in rare instances, a more aggressive clinical course has been observed. This report details a rare case of primary cutaneous spindle cell B-cell follicle center lymphoma, manifested as a prolonged solitary plaque of cicatricial alopecia. In addition, we provide a comprehensive review of existing cases documented in the literature.

Abstract: Poromas are benign adnexal neoplasms of eccrine origin, believed to arise from the outer layer of acrosyringia and upper dermal eccrine ducts, with a predilection for glabrous skin. They typically present as a pink or red papule with a surrounding thin moat on the palms and soles. We report a case of poroma with histopathologic features reminiscent of syringocystadenoma papilliferum (SCAP). A 70-year-old woman presented with a 2.0 cm pedunculated nodule on the left suprapubic abdomen. Histopathologically, the lesion predominantly displayed features of a conventional poroma but also included areas with endophytic invaginations lined by large, plump epithelioid cells with abundant eosinophilic cytoplasm and occasional decapitation secretion, alongside a stroma rich in plasma cells-characteristics suggestive of SCAP. However, definitive bilayers with myoepithelial cells were not observed. Immunohistochemical studies revealed that the tumor cells were positive for TRPS1 (particularly around SCAP-like areas) and CEA (indicating ductal differentiation), but negative for BRAF V600E and NUT. The diagnosis of poroma with apocrine differentiation mimicking SCAP was favored. This unusual morphologic variation in poromas is rare, with fewer than 5 cases documented in the literature. These SCAP-like features likely represent a variation within the morphologic spectrum of poromas rather than the presence of 2 synchronous tumors. Our case highlights the importance of recognizing such variations in poroid neoplasms to ensure accurate diagnosis.

Case presentation: We report a case of erythematoviolaceous cutaneous plaques in an uncommon location (abdomen and dorsum) in a patient with rheumatoid arthritis and without other disorders such as atherosclerotic disease, macromastia and smoking.

Discussion and conclusion: It is believed that ischemia or inflammation creates local hypoxia, leading to an increase in pro-angiogenic cytokines with subsequent endothelial proliferation and neovascularization. We report a case of a patient with rheumatoid arthritis (autoimmune disease) who presented with an asymptomatic cutaneous violaceous and roundish lesion in the trunk that may be related to diffuse dermal angiomatosis.

Abstract: Silicone granulomas, or "siliconomas," are the common foreign-body inflammatory responses to injected silicone material. In rare cases, siliconomas develop remotely from the original site of injection, secondary to silicone migration. If a history of silicone injection is not noted, such lesions risk misdiagnosis (possibly as infection or malignancy). Intraocular silicone oil is commonly used in retinal detachment surgery, with occasional reports of granulomatous responses after its application in this context. Here, we report a 66-year-old man who developed a periocular silicone granuloma years after scleral buckle surgery for a detached retina and summarize the literature of similar reports of migratory siliconoma.

Abstract: Squamomelanocytic tumor is a poorly defined term that indicates co-occurrence of malignant melanoma and squamous cell carcinoma within the same lesion. We present an unusual case of squamomelanocytic tumor in which both intermingling components showed predominantly spindle cell morphology and were confirmed with double staining for SOX-10 and AE1/AE3.

Abstract: The standard treatment of choice for pleomorphic dermal sarcoma (PDS), a relatively uncommon soft tissue sarcoma and 1 morphologically similar to atypical fibroxanthoma, is wide local excision with close clinical follow-up. Studies regarding management of advanced/metastatic PDS with immune checkpoint inhibitors are limited as most STSs have historically been viewed as being immunologically inert. Contradicting this belief, in this report, we describe 2 cases of PDS with a robust host response. Histopathology of both cases revealed a dermal neoplasm comprising mitotically active, pleomorphic, spindled-to-ovoid cells, which were immunohistochemically negative for keratinocytic, melanocytic, and smooth muscle markers. An unusual feature in both cases was the presence of a brisk host response. Additional workup of the infiltrating lymphocyte population revealed an abnormal CD4:CD8 ratio in both cases, with the proportion of CD8 + lymphocytes surpassing (case 1) and equaling (case 2) that of the CD4 + T-lymphocyte population. The increased proportion of CD8 + lymphocytes prompted the additional workup of TCR gene rearrangement, which revealed a clonal population of T lymphocytes in both cases. The robust and clonal T-lymphocyte host response in both of our cases suggests that PDS appears to fit the classic model of an inflammatory-type tumor and may be a candidate for checkpoint inhibition. Future work includes additional reports of cases of PDS with an infiltrating clonal T-lymphocyte population and detailing the function and specificity of the infiltrating T lymphocytes to ascertain whether they have the potential to recognize and lyse the tumors they colonize.

Background: In contrast to early-onset dysplastic nevi, late-onset atypical nevi of the elderly are more often precursors to distinctive nevoid melanomas. PReferentially expressed Antigen in MElanoma (PRAME) immunohistochemistry was applied to delineate the nevoid aspect of late-onset oncogenic nevoid pathway. Inducible Skin-Associated Lymphoid Tissue, regulatory T-cell mesenchymal hubs, has emerged as a translational tool and was used to define nevoid oncogenesis within a dynamic meta-analytic pathway.

Methods: PRAME immunohistochemistry was applied after designating a histopathologic diagnosis. Late-onset atypical nested lentiginous nevus, lentiginous nested melanoma, and hypercellular nested nevoid melanoma were the diagnostic categories. A positive PRAME for melanoma was set at 75% percentage labeling.A wide-ranging published evidence-based database was incorporated to develop a meta-analytic framework for oncogenic nevogenesis. This combined inducible Skin-Associated Lymphoid Tissue incorporating the pleiotropic functions of regulatory T cells regulating immunity and gene regulatory epigenetics as principal modulators.

Results: Concordant-negative PRAME expression was present in 64 of 81 (79%) atypical nested lentiginous nevi, concordant-positive PRAME expression occurred in 54 of 75 (72%) nevoid lentiginous and nested melanomas, and 18 of 23 (78%) nevoid hypercellular nested melanomas.

Conclusions: PRAME expression confirmed the existence of a late-onset oncogenic nevoid pathway that can be defined by histopathology. Subsequent meta-analysis data linked to the meta-analytic framework revealed that PRAME is an epigenetic surrogate antigen expressed because of repression of retinoic acid receptor signaling, preventing ligand-induced retinoic acid cellular differentiation, growth arrest, and apoptosis, and promoting melanoma growth and survival for melanomas. PRAME is only a single antigen within a highly complex dynamic framework that governs nevoid oncogenesis. Significantly, the retinoic acid/retinoic acid receptor complex has been shown to modulate the immunosuppressive arm of regulatory T cells underpinning immune tolerance and is pertinent to the broad framework but is not linked to PRAME expression in this arm.

Abstract: Primary cutaneous gamma delta T-cell lymphoma (PCGDTCL) is a rare type of non-Hodgkin lymphoma accounting for <1% of primary cutaneous T-cell lymphomas. The exact cause of PCGDTCL is not known, however, it is thought that chronic antigen exposure in the skin may lead to immune dysregulation at the site, resulting in abnormal proliferation of mature, post-thymic cytotoxic gamma delta T cells. Mutations are the most common genetic alteration seen in PCGDTCL, while structural abnormalities such as gene fusions are not common. We report a case of PCGDTCL with atypical immunophenotypic features, including expression of CD5 with lack of cytotoxic marker expression, and a structural alteration leading to FYN deletion at exon 8. Recently, it was described that a deletion of the area between FYN exon 8 and TRAF3IP2 intron 2 results in a novel FYN::TRAF3IP2 fusion in peripheral T-cell lymphoma, not otherwise specified. We describe our patient's clinical course, differential diagnosis, and potential implications of FYN deletion on disease pathogenesis. To our knowledge, this is the first report of an FYN structural alteration to be described in PCGDTCL.