Ciliated muconodular papillary tumor (CMPT), recently categorized under bronchiolar adenoma (BA), is a rare benign peripheral lung lesion. Due to its mucin-rich nature and radiological appearance, it frequently mimics invasive mucinous adenocarcinoma (IMA), leading to potential over-treatment. While its indolent nature is known, quantitative data regarding its growth kinetics, specifically tumor volume doubling time (VDT), are lacking. We present a case of CMPT/BA with a 3-year observation period and evaluate its diagnostic utility via VDT calculation. A 72-year-old female with a history of smoking and treated cecal adenocarcinoma presented with an enlarging 1.2 cm irregular, cavitary nodule in the right middle lobe. The lesion had been monitored for 3 years, showing a gradual growth of approximately 0.3 mm every 6 months. Suspecting primary lung cancer or metastasis, a diagnostic resection was performed. Intraoperative findings showed a glistening, mucinous lesion suggestive of IMA, prompting a right middle lobectomy. However, histopathology revealed a tri-layer epithelial composition including ciliated columnar, mucinous, and basal cells. Immunohistochemistry confirmed a continuous basal cell layer (p63/p40 positive) and thyroid transcription factor-1 positive surface epithelium, diagnostic of CMPT/BA. Retrospective 3-dimensional computed tomography volumetry determined the VDT to be 2526 days. CMPT/BA poses a significant diagnostic challenge as a radiological and intraoperative mimic of IMA. In this case, the VDT (2526 days) was markedly longer than the reported mean for IMA (approximately 440 days). Identifying such prolonged doubling times through serial imaging and volumetry can assist clinicians in suspecting benign entities like CMPT/BA, potentially facilitating appropriate treatment strategies.

Follicular thyroid carcinoma (FTC) makes up about 10% of all thyroid cancers and remains a diagnostic challenge due to its striking similarities to follicular thyroid adenoma (FTA). Both conditions share overlapping histopathological features, including vascular and capsular invasion, which complicates accurate diagnosis and often results in unnecessary surgical procedures. These interventions, while precautionary, can impose significant physical, emotional, and financial burdens on patients. As a result, identifying molecular biomarkers that can reliably differentiate between FTC and FTA is essential to improving diagnostic accuracy and optimizing patient care. MicroRNAs (miRNAs) have emerged as promising candidates for this purpose. These small, non-coding RNAs are key regulators of gene expression and are frequently dysregulated in cancer. In this study, we examined the expression of miR-221/222, miR-224, and miR-339 in formalin-fixed, paraffin-embedded (FFPE) tissue samples obtained from 48 patients, including 16 cases each of FTC, FTA, and multinodular goiter (MNG) as controls. Using quantitative real-time PCR (qRT-PCR), we found significant overexpression of miR-221/222 and miR-224 in FTC and FTA compared to MNG samples (p < 0.05). Although miR-339 expression was higher in FTC than in FTA, the difference was insignificant. Receiver operating characteristic (ROC) curve analysis demonstrated that these miRNAs have the potential to serve as reliable biomarkers, with strong sensitivity and specificity in distinguishing malignant from benign thyroid nodules. Our findings emphasize the role of miRNAs as powerful diagnostic tools that could transform the current approach to thyroid nodule management. By incorporating miRNA profiling into clinical workflows, it may be possible to reduce unnecessary surgeries, improve patient outcomes, and effectively tailor treatment strategies. To fully realize the potential of miRNAs in thyroid cancer diagnostics, further research involving larger sample sizes and diverse tissue types is needed. Such efforts could pave the way for their integration into routine clinical practice and open new avenues for targeted therapies.