American Journal of Dermatopathology最新文献

Abstract: Comparing studies of molecular ancillary diagnostic tests for difficult-to-diagnose cutaneous melanocytic neoplasms presents a methodological challenge, given the disparate ways accuracy metrics are calculated. A recent report by Boothby-Shoemaker et al investigating the real-world accuracy of the 23-gene expression profile (23-GEP) test highlights this methodological difficulty, reporting lower accuracy than previously observed. However, their calculation method-with indeterminate test results defined as either false positive or false negative-was different than those used in previous studies. We corrected for these differences and recalculated their reported accuracy metrics in the same manner as the previous studies to enable appropriate comparison with previously published reports. This corrected analysis showed a sensitivity of 92.1% (95% confidence interval [CI], 82.1%-100%) and specificity of 94.4% (91.6%-96.9%). We then compared these results directly to previous studies with >25 benign and >25 malignant cases with outcomes and/or concordant histopathological diagnosis by ≥3 dermatopathologists. All studies assessed had enrollment imbalances of benign versus malignant patients (0.8-7.0 ratio), so balanced cohorts were resampled according to the lowest common denominator to calculate point estimates and CIs for accuracy metrics. Overall, we found no statistically significant differences in the ranges of 23-GEP sensitivity, 90.4%-96.3% (95% CI, 80.8%-100%), specificity, 87.3%-96.2% (78.2%-100%), positive predictive value, 88.5%-96.1% (81.5%-100%), or negative predictive value, 91.1%-96.3% (83.6%-100%) between previous studies and the cohort from Boothby-Shoemaker et al with this unified methodological approach. Rigorous standardization of calculation methods is necessary when the goal is direct cross-study comparability.

Abstract: Cutaneous larva migrans (CLM) is an ectoparasitic infestation predominantly caused by nematodes, specifically Ancylostoma braziliense and Ancylostoma caninum, found in tropical and subtropical regions. Although follicular involvement by the parasite is a rare manifestation, with approximately 20 cases reported in the English literature, its pathogenesis remains underexplored. The present study reports 2 cases of CLM presenting with follicular involvement in patients with pruritic lesions following travel to subtropical areas. The first of them is a 32-year-old woman who developed an abdominal skin lesion subsequent to a trip to Thailand and the second is a 28-year-old woman who exhibited a knee lesion after a volunteer mission in Senegal. Histologic examination revealed characteristic features of CLM, such as nematode larvae traversing the hair follicle. The hookworm larvae were observed creating tunnels within the external root sheath. In addition, they were interfacing with the vitreous layer, sparing the perifollicular connective tissue sheath and the Henle layer, and approaching the vicinity of the hair bulb. The application of skin ultrasound to guide the biopsy facilitated the visualization and identification of the parasite within the follicle in the latter case. This study not only underscores follicular involvement in CLM but also provides insights into its anatomopathological presentation and spread through the hair follicle.

Abstract: Anetoderma is an uncommonly reported dermatosis clinically characterized by discrete skin lesions resulting from elastic fiber loss within the dermis. Although primary anetoderma has been considered idiopathic, a range of associated disorders, particularly prothrombotic abnormalities, have been reported. We present a 79-year-old woman with a heterozygous Factor V Leiden mutation who developed anetoderma shortly after COVID-19 infection complicated by a thromboembolic event. Our patient adds to the literature on the occurrence of anetoderma in the setting of infection and/or a prothrombotic disorder.

Abstract: Primary cutaneous sarcomatoid squamous cell carcinoma can show significant histologic overlap with other malignant spindle cell tumors, posing a diagnostic challenge. Even with a wide array of immunohistochemical markers, the exact line of differentiation can be a challenge to identify in some cases. The picture is further complicated by the aberrant expression of myofibroblastic markers [such as smooth muscle actin (SMA)] by these neoplasms, along with a concomitant loss of conventional epithelial markers. The histologic differential diagnoses of primary cutaneous sarcomatoid squamous cell carcinoma include desmoplastic melanoma, leiomyosarcoma, and spindle cell atypical fibroxanthoma/pleomorphic dermal sarcoma (AFX/PDS). A retrospective analysis of 16 cases of PCSSCCs with SMA expression, obtained from large academic institutions, was performed and is summarized below. The tumors were in the scalp (6 cases), arm (4 cases), leg (2 cases), face (2 cases), hand (1 case), and neck (1 case). Immunohistochemical studies were performed in all cases with the following antibodies: AE1/AE3, CAM 5.2, MNF-116, p63, p40, CK5/6, S-100, SOX10, SMA, desmin, calponin, H-caldesmon, CD10, CD68, CD163, and CD34. Histopathologically, all cases were classified as high-grade malignant poorly differentiated neoplasms. Tumors were characterized by an infiltrative neoplasm that involved the entire reticular dermis and, in 7 cases, the subcutaneous fat. Three cases were associated with a well-differentiated squamous cell component. The neoplasms were composed of atypical spindle and epithelioid cells arranged in long and intersecting fascicles. All neoplasms were positive for epithelial markers (at least 1 marker), and all cases were strongly positive for SMA. Our data emphasize the diagnostic utility of multiple epithelial markers as a first screening tool in the detection and workup of malignant cutaneous sarcomatoid neoplasms. Awareness of SMA expression in these tumors can complicate its diagnosis, and it is important to recognize this aberrant immunophenotype to facilitate definitive diagnosis and avoid misdiagnosis.

Abstract: Nail involvement in Langerhans cell histiocytosis is rarely reported in the literature. According to the reported cases, it is believed that the involvement of nails has a poor prognosis because of multisystem involvement. Performing a nail bed biopsy might be challenging for children. We report a child in whom nail bed biopsy served as the sole clue to the diagnosis of Langerhans cell histiocytosis in absentia of skin clue on a background of advanced multisystem involvement.

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.

Background: Being one of the largest dermatology groups in the country with an in-house pathology laboratory, we have seen a significant increase in the number of adhesive-based pigmented lesion assays (ABPLAs) in addition to biopsies and excisions following a moderate-risk or high-risk result with this test.

Objective: To report our clinical experience and independently confirm that our results with this ABPLA (Pigmented lesion assay, DermTech. San Diego, CA) are consistent with the results of the validation studies completed by the test manufacturer.

Methods: A retrospective review of our electronic medical records for results of ABPLAs, corresponding histopathologic results and available clinical follow-up, along with their statistical analysis was completed.

Results: After reviewing our electronic medical records, we found that 893 ABPLAs for pigmented lesions concerning for melanoma were obtained in a period of 14 months. Of the 893 ABPLAs completed, 161 biopsies and excisions were performed after the initial results of these assays. Additional clinical follow-up data were recorded and used for the statistical analysis of the performance and accuracy of this test.

Limitations: The small number of lesions reported as low risk for melanoma with corresponding histopathologic results limits our evaluation of the performance of this test. In addition, there may have been some melanomas that were not identified because the duration of the clinical follow-up was insufficient or because some patients were lost to follow-up.

Conclusion: In our experience this ABPLA has a sensitivity of 92.0%, a specificity of 79.5%, a positive predictive value of 16.9%, and a negative predictive value of 99.5% for the detection of melanoma.

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: 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.