American Journal of Dermatopathology最新文献

Abstract: The conventional morphological characteristics of Wnt-activated deep penetrating/plexiform melanocytomas/nevi (DPN) are those of large spindled or epithelioid melanocytes with distinctive voluminous amphophilic cytoplasm, fine pigmented granules, and surrounding melanophages. The central molecular hallmark is the activation of the Wnt-pathway predominantly driven by mutations in the beta-catenin ( CTNNB1 ) gene. Although typically lacking a junctional component, a lesser-known superficial variant with a junctional component has been identified, which could potentially lead to diagnostic challenges. This study presents a cohort of 11 such cases displaying a junctional component of DPN from 10 patients (5 women and 5 men; age range: 27-78 years; median age: 51 years). The nevi were distributed as follows: 1 conjunctival, 1 scalp, 2 lower limb, and 6 truncal lesions. Eight cases were combined with a conventional nevus, 2 cases displayed pure DPN cytology exhibiting only a junctional element, and 9 cases exhibited some degree of lentiginous architecture. All cases demonstrated a low mitotic index (<1 mitosis/mm 2 ). Immunohistochemistry revealed positive BRAF V600E staining in 8 cases (8/11), whereas all cases tested (11/11) were PRAME negative. Nuclear beta-catenin and LEF1 staining was consistently strong and diffuse with DPN cytology (11/11), along with robust cyclin D1 staining in all cases tested (11/11). By contrast, all 9 conventional nevi showed an absence of nuclear beta-catenin staining (0/9) and weaker, mosaic-type LEF1 and cyclin D1 staining was observed. This study emphasizes the diagnostic challenge these nevi can pose in the absence of a conventional, deeper DPN component, which can potentially be misdiagnosed as melanoma.

Abstract: We present the histopathology of 12 skin biopsies from 6 patients with vacuoles, enzyme E1, X-linked, autoinflammatory, somatic syndrome and review the literature. The age of these 6 men ranges from 62 to 83 years (median of 70 years). UBA1 mutation was documented in all 6 patients. Multiple organ systems were involved with constitutional symptoms noted in 4 of 6 patients (67%), cutaneous involvement in 6 of 6 patients (100%), hematologic abnormalities in 6 of 6 patients (100%), pulmonary involvement in 4 of 6 patients (67%), musculoskeletal abnormalities in 3 of 6 patients (50%), vascular thrombosis in 2 of 6 patients (33%), ocular involvement in 2 of 6 patients (33%), and gastrointestinal involvement in 5 of 6 patients (83%). Of the 6 presented patients, neutrophilic dermatosis was seen in 3 biopsies, histiocytoid neutrophilic dermatosis in 1 biopsy, neutrophilic dermatosis with vasculitis in 1 biopsy, neutrophilic and granulomatous dermatitis in 2 biopsies, septal panniculitis consistent with erythema nodosum in 2 biopsies, and nonspecific patterns in 3 biopsies. In summary, neutrophilic dermatosis, small-vessel vasculitis, and panniculitis are frequent histopathologic patterns noted in decreasing frequency in skin biopsies of the patients with vacuoles, enzyme E1, X-linked, autoinflammatory, somatic syndrome. However, the histopathologic findings can be diverse, nonspecific in some instances, and varied among different biopsies obtained from the same patient.

Background: Cellulitis is a significant public health burden and lacks a gold standard for diagnosis. Up to 1/3 of patients are incorrectly diagnosed. The skin biopsy has been proposed as the gold standard.

Objective: In this study, we evaluate the histopathologic characteristics and tissue culture positivity of biopsies in patients diagnosed with cellulitis seen by our inpatient dermatology consultation service.

Methods: This retrospective cohort study examined patients who were hospitalized with a skin and soft tissue infection at our institution between 2011 and 2020 and underwent a skin biopsy.

Results: Those with a positive tissue culture were more likely to die within 30 days compared with those with negative tissue cultures (26% vs. 6%, P = 0.048). Patients who died within 30 days were more likely to have acute interstitial inflammation as a feature on histopathology (38%, P = 0.03).

Limitations: Single institutional design, unintentional exclusion of patients with organism-specific diagnosis, and selection for a medically complex patient population because of the nonroutine collection of biopsies.

Conclusion: Positive tissue cultures and histopathology showing acute interstitial space inflammation on skin and soft tissue infection (SSTI) biopsies are associated with increased mortality and thus may serve as indicators of poor prognosis.

Abstract: We report the case of a 72-year-old man with bilateral testicular involvement by mycosis fungoides (MF). The patient was diagnosed with MF 6 months prior, and testicular involvement was found upon staging. The rare behavior of MF, with early visceral involvement and no hematolymphoid organs affected, had a poor prognosis with patient death 14 months after the original diagnosis despite surgery and chemotherapy. The neoplastic cells showed a phenotypic switch from a CD4 + /CD8 - profile in the skin to a CD4 - /CD8 - in the testis and the same clone, confirmed with T-cell receptor gene rearrangement studies, making this the third reported case of MF affecting the testis and the first with clonality studies to confirm it. The clinical evolution may be related to its distinctive biology showcased in the neoplastic cell's switch to a more aggressive CD4 - /CD8 - profile and the early extension of the disease to an uncommon visceral site.

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: Paratesticular mesothelioma (malignant mesothelioma arising from the tunica vaginalis of the testis) represents a small proportion of mesothelial neoplasms, and cutaneous involvement by paratesticular mesothelioma is very rare. Cutaneous involvement can manifest as scrotal subcutaneous nodules from regional spread, distant metastasis, or direct extension through surgical scars. Mesothelioma has 3 histopathologic classifications that include epithelioid, biphasic, and sarcomatoid, which is rarely seen in paratesticular mesothelioma. Given the rarity of this condition, cutaneous mesothelioma may be misdiagnosed as histologic mimics, such as metastatic adenocarcinoma or adnexal neoplasms; thus, appropriate immunohistochemical workup and clinical correlation are required to make an accurate diagnosis. In this case, a 75-year-old man with a history of paratesticular mesothelioma, status postorchiectomy, presented with right-sided scrotal swelling, erythema, and subcutaneous nodules. These nodules were identified as local recurrence with cutaneous involvement by paratesticular mesothelioma on histopathologic examination. This case highlights the clinical and histopathologic features of this diagnosis and underscores the importance of dermatopathologists being aware of this condition to ensure accurate diagnosis.

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.