Prevalence of mesothelin expression in peritoneal disease from colorectal and appendiceal cancers.

BACKGROUND: Mesothelin is a cell surface glycoprotein overexpressed in 28%-58% of colorectal cancer (CRC). We hypothesized that CRC mesothelin expression contributes to peritoneal spread and that it is selectively overexpressed in those with peritoneal metastasis versus distant metastasis. METHODS: This case-controlled study involved mesothelin immunohistochemistry staining of tumor specimens from patients with metastatic CRC/appendiceal cancers between 2017 and 2019. Staining reactivity was graded from trace to 4+ (low ≤1+; high >1+). Staining patterns were characterized on global (focal/patchy/diffuse) and cellular (apical/cytoplasmic) levels. Immunostaining of normal mesothelial cells served as internal control. RESULTS: Thirty-one patients were identified: 11 peritoneal (study) and 20 distant metastasis (control). The control group did not include appendiceal cancers. The study group had greater proportion of high staining reactivity (55% vs. 5%; odds ratio [OR] = 20.4, 95% confidence interval [CI] 1.96-211.8). The study group had more diffuse (36% vs. 0%; OR = 22.2, 95% CI 1.1-465.3) and cytoplasmic staining patterns (73% vs. 28%; OR = 6.9, 95% CI 1.3-37.2). CONCLUSION: Mesothelin expression is higher in CRC/appendiceal cancers with peritoneal metastasis than those with distant metastasis. Immunohistochemistry staining patterns suggestive of propensity towards peritoneal metastasis include diffuse and cytoplasmic staining. Mesothelin may be a potential target for novel treatments of CRC/appendiceal carcinoma with peritoneal involvement.

New observation of microcystic macular edema as a mild form of cystoid macular lesions after standard phacoemulsification: Prevalence and risk factors.

We present the new observations of postoperative microcystic macular edema (MME) as a mild form of cystoid macular lesions (CMLs) after standard phacoemulsification.To report the incidence, risk factors, and pathophysiology of MME compared to conventional concept of pseudophakic cystoid macular edema (CME), we retrospectively reviewed patients' records. Pseudophakic CMLs were defined as any cystic fluid collections that were newly formed after cataract surgery, confirmed by preoperative and postoperative optical coherence tomography (OCT) examinations. CMLs were classified into 2 groups, which are CME and MME, according to the change the central retinal thickness. The dataset consisted of 316 patients (mean age, 67.52 ±â€Š12.95 years; range, 42-87 years). Topical nonsteroidal anti-inflammatory drug (NSAID) were administered in 197 eyes during the perioperative period; 147 eyes were not treated. CMLs were present in 22 out of 344 (6.39%) eyes. Six of 344 eyes (1.74%) had CME and 16 of 344 eyes (4.65%) had MME. The incidence of MME significantly decreased in the group of patients treated with topical NSAIDs (P = .039), while the incidence of CME was not different in both groups (P = .408). All of the patients with MME were experienced improvement with only topical NSAIDs. However, 67% (4/6) of patients with CME did not improve with topical NSAIDs alone and needed additional treatments. Pseudophakic MMEs were more likely to have a history of diabetic retinopathy, epiretinal membrane, and eyes were not treated with topical NSAID.This study showed a wide clinical spectrum of CMLs. MME has not been included in the conventional definition of pseudophakic CME. Topical NSAIDs could decrease the CML incidence. People with risk factors for CML should use topical NSAIDs and undergo regular follow-up OCT examinations.