American Journal of Dermatopathology最新文献

Abstract: Pulse granulomas are unusual foreign body reactions to exogenous plant material, featuring the presence of hyaline ring structures and granulomatous inflammation. Pulse granulomas have been reported to occur in the oral cavity, gastrointestinal tract, and respiratory tract. Cutaneous pulse granulomas are exceedingly rare. All reported cases have been closely associated with underlying pathology such as chronic inflammatory conditions, trauma, or surgical procedures which likely facilitated implantation of exogenous plant material. We report a novel case of a cutaneous pulse granuloma presenting in the perianal region of an otherwise healthy man. The authors propose that the source of the exogenous plant material is plant-derived baby wipes, which the patient had been using daily to the perianal region.

Abstract: Malignant proliferating pilar tumors (MPPTs) are rare, unique cutaneous adnexal tumors. Sarcomatous transformation in MPPTs is even rarer (4 previous cases reported). Here, we report an extraordinary case of a MPPT with sarcomatous transformation occurring on the scalp of a 63-year-old man with an in-depth molecular profile along with histologic, immunohistochemical, and follow-up data. Shared mutations in the epithelial and sarcomatous components included a loss-of-function TP53 mutation. An inactivating TP53 mutation was only identified in the epithelial component, and an inactivating CDKN2A mutation was only identified in the sarcomatous component. Copy number variations previously reported in MPPT were also identified, including 6p21.1 loss, 6q arm loss, and 15q21.1-q26.3 gain [epithelial], and 6p22.2-p22.3 loss [sarcoma]. Histologically, the tumor demonstrated juxtaposed areas of proliferating pilar tumor, carcinoma with clear cell change, and sarcomatous areas that did not stain for AE1/AE3, p40, CD34, S100 protein, and smooth muscle actin  by immunohistochemistry. The patient is alive at 2 years without evidence of recurrence or metastasis.

Abstract: Clinical correlation is essential to accurate and efficient diagnosis and differential diagnosis in dermatopathology. Poor-quality clinical information can lead to failures and delays in patient care. Some clinicians use the term "unlikely" when submitting a specimen. How frequently the "unlikely" clinical diagnosis correlates with the final pathologic diagnosis is unknown. We studied 203 dermatopathology reports from December 8, 2020, to July 1, 2021, that included the qualifier "unlikely" on the requisition sheet. Samples were stratified into either an inflammatory or neoplastic cohort based on final histopathologic diagnosis, with the neoplastic cohort being further stratified into pigmented and nonpigmented cohorts. Statistical analyses were conducted. The "unlikely" diagnosis in the clinical differential diagnosis and the final histologic diagnosis were the same in 7.9% of the 203 samples studied. This occurred in 8.5% of the inflammatory cohort and 7.6% of the neoplastic cohort. We concluded that the use of the qualifier "unlikely" is not helpful. We acknowledge the limitations of our study because of a small sample.

Abstract: Pseudolipoblastic perineurioma is a very uncommon variant of extraneural perineurioma, with only a limited number of cases documented in the medical literature. The most remarkable histopathologic characteristic is the existence of vacuolated cells that closely resemble lipoblasts; besides the presence of small, spindle shaped, or epithelioid perineurial cells. In this study, we present another case of pseudolipoblastic perineurioma, predominantly characterized by the presence of vacuolated "pseudolipoblastic" cells. The immunohistochemical expression of EMA, Glut-1, claudin-1, collagen type IV, and laminin as well as S-100 negativity is essential for the diagnosis to support the perineurial origin. Simple excision is the best treatment option for these benign tumors that do not recur or metastasize. It is crucial to recognize this rare entity to differentiate it from many other tumors characterized by prominent intracytoplasmic vacuoles.

Abstract: The presence of multiple cutaneous vascular lesions in infancy can signal the possibility of visceral involvement. Dermatopathologists must appreciate how the differential diagnosis includes entities that have distinct therapeutic and prognostic implications. Fortunately, these rare entities can be distinguished histopathologically with the help of clinicopathologic correlation and immunohistochemistry. In this article, we discuss congenital disseminated pyogenic granuloma, multifocal infantile hemangioma, and multifocal lymphangioendotheliomatosis with thrombocytopenia. Subtle morphologic and immunophenotypic features permit their distinction, which in turn is important for identifying extracutaneous manifestations and effective treatments. We present a case of a 3-week-old infant with congenital disseminated pyogenic granuloma involving the skin and the liver whose lesions regressed without therapeutic intervention over 6 months of close follow-up. We review the literature on these rare, overlapping entities and present an approach to resolving the differential diagnosis.

Abstract: Cervical cancer stands as one of the most common gynecologic malignancies in developing countries; however, cutaneous metastasis from cervical cancer is a rare occurrence. In this study, we present a case involving a 44-year-old woman diagnosed with International Federation of Gynecology and Obstetrics stage IIA gastric-type endocervical adenocarcinoma. Two years later, after undergoing radical hysterectomy and chemoradiation therapy, she exhibited cutaneous metastasis in the vulvar region.

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.