Objectives: To examine and summarize the current literature on serologic methods for the detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: A literature review was performed using searches in databases including PubMed, medRxiv, and bioRxiv. Thirty-two peer-reviewed papers and 23 preprints were examined. Results: The studies included lateral flow immunoassay, enzyme-linked immunosorbent assay, chemiluminescence immunoassay, and neutralizing antibody assays. The use of all major SARS-CoV-2 antigens was demonstrated to have diagnostic value. Assays measuring total antibody reactivity had the highest sensitivity. In addition, all the methods provided opportunities to characterize the humoral immune response by isotype. The combined use of IgM and IgG detection resulted in a higher sensitivity than that observed when detecting either isotype alone. Although IgA was rarely studied, it was also demonstrated to be a sensitive marker of infection, and levels correlated with disease severity and neutralizing activity. Conclusions: The use of serologic testing, in conjunction with reverse transcription polymerase chain reaction testing, was demonstrated to significantly increase the sensitivity of detection of patients infected with SARS-CoV-2. There was conflicting evidence regarding whether antibody titers correlated with clinical severity. However, preliminary investigations indicated some immunoassays may be a surrogate for the prediction of neutralizing antibody titers and the selection of recovered patients for convalescent serum donation.

Immunohistochemistry for estrogen receptor may be used to distinguish metastatic breast cancers from adenocarcinomas of other sites, including those of the lung. The estrogen receptor exists as 2 subtypes, alpha and beta. Estrogen receptor alpha is the predominant subtype expressed by more than two-thirds of human breast cancers. Adenocarcinomas of lung origin may also express estrogen receptor, primarily the beta subtype. Human estrogen receptor alpha is highly homologous to estrogen receptor beta and consequently, antibodies used to detect estrogen receptor alpha in breast carcinomas may detect estrogen receptor beta in pulmonary adenocarcinomas. We investigated the immunohistochemical expression of estrogen receptor in proven primary lung adenocarcinomas using 3 anti-estrogen receptor alpha antibodies: mouse monoclonal 1D5, 6F11, and rabbit monoclonal SP1. Ninety-two pulmonary adenocarcinomas (53 women and 39 men) confirmed by clinical presentation and positive immunohistochemistry for thyroid transcription factor-1 (TTF-1) were included in this study. There were 19 incisional biopsies and 73 excisional specimens. Immunohistochemistry for estrogen receptor using antibodies 1D5, 6F11, and SP1 was performed on formalin-fixed, paraffin-embedded tissue following antigen retrieval. Any nuclear reactivity for estrogen receptor was considered a positive result. Focal positive nuclear reaction for estrogen receptor was detected in 7 (7.6%) cases of primary pulmonary adenocarcinoma using antibody 1D5, 13 (14.1%) using 6F11, and 25 (27.2%) using SP1. The differences in reactivity for estrogen receptor in pulmonary adenocarcinomas between SP1 and 1D5, and between SP1 and 6F11 were statistically significant (P<0.001). Positive cases showed only a focal pattern of staining with each of the 3 antibodies. There was no significant difference in reactivity for estrogen receptor in pulmonary adenocarcinomas of men and women. Positive staining was highest in nonmucinous bronchioloalveolar adenocarcinomas for all of the antibodies, and for SP1, variation by histologic subtype was significant (P<0.001). SP1 has a significantly higher detection rate for the expression of estrogen receptor in pulmonary adenocarcinomas when compared with either 1D5 or 6F11. Caution should therefore be exercised in the use of this antibody alone in distinguishing a metastatic breast from a primary pulmonary adenocarcinoma.

Gestational trophoblastic disease occurs in less than 1 per 1200 pregnancies in the United States. The spectrum of this disease ranges from benign hydatidiform mole to trophoblastic malignancy (placental-site trophoblastic tumor and choriocarcinoma). Benign gestational trophoblastic disease generally occurs in women of reproductive age and is extremely rare in postmenopausal women. To our knowledge, our case represents only the third description in the world literature of a benign complete hydatidiform mole in a woman with a history of amenorrhea greater than 1 year. We describe the case of a 61-year-old postmenopausal woman who underwent an emergent total abdominal hysterectomy due to uncontrollable vaginal bleeding associated with an increased serum β-human chorionic gonadotropin level. The resected uterus contained an endometrial, cystic, grapelike tumor. Microscopic examination demonstrated hydropic degenerated villi with a circumferential trophoblastic cell proliferation and moderate atypia, consistent with a complete hydatidiform mole. The morphologic and immunophenotypic characteristics are presented, as well as the results of a literature review.

Background/Objectives: Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer, with a lifetime risk of 14–20% that is rising every year. Although prognosis for cSCC is generally good, certain high-risk features of cSCC portend increased rates of nodal and distant metastasis, recurrence, and disease-specific mortality. One such high-risk factor is perineural invasion (PNI), which is broadly defined as the invasion of cancer into and around nerves. Compared to other high-risk factors, PNI presence is associated with the highest risk for locoregional and distant metastasis. Still, the mechanisms underlying the pathogenesis of PNI remain poorly understood. Recent studies suggest the migration and invasion of tumors into nerves is a result of complex molecular crosstalk within the tumor-nerve microenvironment, wherein the milieu of signaling molecules simultaneously promote neuronal growth and tumor cell invasion. Methods: Understanding the molecular and cellular mechanisms that promote PNI will lead to future developments of targeted therapies that may improve locoregional control and survival. Results/Conclusions: In our article, we aim to provide a comprehensive review of recent findings about the pathogenesis of PNI, clinical implications of PNI-positive disease in cSCC, available treatment modalities, and potential future therapeutic targets.

Perineural invasion (PNI) is a well-recognized histopathologic feature in multiple malignancies; however, its significance in breast cancer remains relatively underexplored. This review provides a synopsis of the current knowledge on PNI in breast cancer, discussing its histopathologic features, molecular mechanisms, diagnostic challenges, and clinical relevance. PNI is most frequently observed in high-grade invasive ductal carcinoma (IDC), particularly in triple-negative and HER2-positive subtypes. It is also seen in special histological subtypes such as mixed, metaplastic, and invasive micropapillary carcinomas. Mechanistically, PNI involves tumor–neural interactions, including neurotrophic factor signaling and epithelial–mesenchymal transition, contributing to tumor progression and potential locoregional recurrence (LRR). While PNI is linked to adverse prognosis in other tumors, its independent role remains unclear in breast cancer due to limited large-scale studies. Therefore, further investigation into its prognostic significance and potential therapeutic implications is needed. Future research should focus on refining diagnostic criteria and assessing targeted therapies to mitigate PNI-associated progression. This review summarizes the current knowledge on perineural invasion (PNI) in breast cancer, addressing its histological features, molecular mechanisms, diagnostic challenges, and clinical implications.