American Journal of Dermatopathology最新文献

Abstract: Although CD20 expression is typically scarce in mycosis fungoides (MF), it is more commonly associated with T-cell lymphomas. Nevertheless, isolated instances of CD20-positive MF have been documented infrequently. Here, we present a unique case of CD20-positive MF in a 30-year-old man who manifested with a hypopigmented patch on the anterior chest. Histopathological examination revealed epidermotropic infiltrates of small- to medium-sized lymphocytes with hyperchromatic and cerebriform nuclei aligned along the basal and low-mid layers of the epidermis. Immunophenotypic analysis demonstrated neoplastic T cells expressing CD4+, CD8+, and CD3+ with the loss of CD7. Intriguingly, a notable subset of the neoplastic T cells exhibited CD20 expression. This case contributes to the sparse literature on CD20-positive MF and underscores its diagnostic and clinical ramifications. The role of B cells has been more thoroughly characterized in T-cell lymphomas other than MF. However, its significance in MF remains unclear due to the scarcity of reported cases. Some hypotheses propose that the B cells' expression might indicate immune dysregulation or complex interactions within the tumor microenvironment. Another perspective suggests it could signify a progression of the disease towards a more aggressive lymphoma phenotype. Further investigation and documentation of similar cases is imperative to elucidate the clinical features, prognosis, and optimal therapeutic strategies. The long-term prognosis and outcomes in patients with hypopigmented MF and CD20 positivity remain ambiguous, underscoring the necessity for continued research and scrutiny of analogous cases.

Abstract: Cutaneous deciduosis is an extremely rare condition that clinically presents as a nodular lesion in the skin as a scar or neoplasm. Histologically, this may pose a diagnostic challenge simulating malignant epithelioid neoplasms including sarcoma. Histologically, a nodular growth pattern of large monomorphic epithelioid cells is observed. The epithelioid cells in deciduosis can appear atypical with considerable nuclear pleomorphism, mimicking a malignancy. These features can be misinterpreted as a primary cutaneous or metastatic malignancy by dermatopathologists who are not familiar with gynecologic pathology. Failure to correctly diagnose this condition may result in unnecessary diagnostic studies for the patient. In this article, we report a case of cutaneous deciduosis in a 35-year-old woman with a cesarean scar. Histological examination revealed nodular proliferation of large epithelioid cells with pale eosinophilic cytoplasm and large nuclei with prominent nucleoli. Compressed atrophic slit-like glands resembling endometrial glands were present in some areas. Histopathological features of decidual cells, along with appropriate immunohistochemical studies, help establish the diagnosis and rule out other neoplastic mimics of deciduosis.

Abstract: Spitz melanocytic neoplasms exhibit frequent chromosomal rearrangements leading to recurring gene fusions, such as ALK fusions. TPM3 and DCTN1 emerge as the predominant fusion partners of ALK , although less common partners such as NPM1 , TPR , CLIP1 , GTF3C2 , MLPH , EEF2 , MYO5A , and KANK1 have also been documented. Although ALK fusions are primarily associated with Spitz nevi or atypical Spitz tumors, instances of Spitz melanoma with ALK fusions documented in the English literature are exceedingly rare. Here, we present a case of Spitz melanoma harboring SLC20A1::ALK fusion, highlighting a novel fusion transcript not previously reported in Spitz melanocytic neoplasms, including Spitz melanomas. In addition, the tumor exhibits multiple aberrant chromosomal alterations characteristic of melanoma, along with a somatic mutation in GRM3 .

Abstract: Extramammary Paget disease (EMPD) is a rare cutaneous malignancy, typically presenting as eczema-like lesions in areas rich in apocrine glands such as the perineum. Here, we report a case of EMPD presenting as a prominent pedunculated neoplasm in a 65-year-old woman. Despite initial misdiagnosis and treatment, biopsy confirmed EMPD infiltration. Following surgical excision, the patient developed brain metastases, indicating a poor prognosis. EMPD's pathogenesis remains unclear, but distinguishing primary from secondary forms is crucial for prognosis and treatment. Our case underscores the importance of recognizing atypical EMPD presentations for timely intervention and improved outcomes.

Abstract: Adrenocortical carcinoma is a very rare oncologic condition with poor prognosis that usually metastasizes to the lungs, liver, local lymph nodes, and peritoneum at initial presentation. However, skin metastasis is very uncommon and has rarely been reported even in advanced stages of the disease. We present a case of a 41-year-old man with a known history of adrenocortical carcinoma of the right adrenal gland that presented with an arm mass. The histopathologic sections showed a multinodular necrotic malignant neoplasm in dermis and subcutaneous fat composed of atypical epithelioid cells with ample granular cytoplasm and pleomorphic vesicular nuclei with frequent intranuclear inclusions and atypical mitoses. The immunohistochemical stains showed tumor cells that were strongly positive for synaptophysin and inhibin, only focally positive for Melan-A, and negative for AE1/AE3. The histopathologic features and the immunohistochemical profile confirmed the diagnosis of metastatic carcinoma consistent with adrenal cortical origin. The diagnosis can be difficult (especially when no clinical data are provided), and an immunohistochemical battery is often useful in distinguishing this tumor from other tumors with similar cytomorphological features.

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: 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.