No abstract

A 46-year-old woman with giant chondrosarcoma of the sternum underwent wide full-thickness resection of the anterior chest wall, which included the pericardium and lung. The free rectus abdominus musculocutaneous flap was transplanted onto prosthetic meshes placed in two layers. While stability and esthetic effect were both good, the subsequent infection in the space between the two meshes prolonged for one month. As a result, the space was closed with an omentum flap. As a consequence, we recommend one-stage omentopexy to prevent the space problem between the two meshes.

Ciliated muconodular papillary tumor/bronchiolar adenoma (CMPT/BA) is a benign tumor with a high frequency of BRAF or EGFR mutations. It remains unclear whether CMPT/BA is associated with a speci c type of lung cancer. Thus, we studied the clinicopathological and genetic characteristics of cases with coexisting CMPT/BA and primary lung cancer to explore this relationship. Among 1945 patients with resected stage 0-III primary lung cancer between 2015-2018, we identi ed eight patients with concurrent CMPT/BA (lung cancer associated with CMPT/BA; LCCM). We compared the gene mutation status of each lesion according to the target sequence using macro-dissected formalin-xed para n-embedded specimens. Whole-exon sequencing (WES) was performed for six lung cancer cases. The LCCM cohort was male-dominant (male:female = 6:2); the median age was 72 years (range 66-81); and most were smokers (six smokers). The most common histological type corresponding to LCCM was adenocarcinoma; however, two squamous cell carcinomas and one small cell carcinoma were also detected. CMPT/BA lesions in LCCM showed a median size of 0.5 cm (range 0.3-1.1). The mutational test revealed no shared mutations between CMPT/BA and lung cancer, except for one invasive mucinous adenocarcinoma (IMA) harboring an HRAS mutation (I46N, c.137T > A). HRAS (I46N) is a rare variant, and all tumors showed an approximately 50% variant allele frequency, suggesting a single nucleotide polymorphism. Other driver gene alterations in lung cancer included EGFR (InDel, n = 2), BRAF (V600E) (n = 1), KRAS (n = 2), GNAS (n = 1), and TP53 (n = 2) mutations. BRAF (V600E) was the most frequent mutation in CMPT/BA. In contrast, lung cancer showed no speci c trend in driver gene mutations. In conclusion, our study revealed differences in the gene mutation pro les of CMPT/BA and lung cancer in coexisting cases, suggesting a mostly independent tumorigenesis of CMPT/BA from lung cancer, except for one IMA with a rare HRAS SNV.

Invasive mucinous adenocarcinoma (IMA) of the lung shares some clinicopathological features with mucinous carcinoma of other organs, such as the ovary. Sarcoma-like lesions, called mural nodules, have been reported in the cystic walls of ovarian mucinous tumors. In this study, we analyzed 213 surgically resected cases of IMA of the lung to determine whether similar mural nodule-like lesions were present. We considered abrupt discrete lesions composed of dedifferentiated tumor cells as mural nodule-like lesions. Of 213 IMAs, we identified 11 tumors with mural nodule-like lesions that were histologically categorized into three subtypes similar to those in the ovary. The sarcomatoid and anaplastic carcinoma-like nodules were composed of spindle cell proliferations and polygonal undifferentiated carcinoma, respectively. Sarcoma-like lesions mimicked sarcomatoid nodules, but the spindle cell proliferations were considered a fibroblastic reaction to the scattered, isolated clusters of tumor cells. Molecular analysis of the components of differentiated IMAs and mural nodule-like lesions revealed a clonal relationship, suggesting a spectrum of tumors with different histology. Clinicopathologically, an older age, the male sex, and smokers were significantly associated with IMAs with mural nodule-like lesions. Notably, patient outcomes were unaffected by the presence or absence of these lesions. Our findings demonstrated that IMA of the lung rarely develops mural nodule-like lesions (11 of 213, 5%). Despite a histological impression of clinical aggressiveness, there was no clear trend in patient outcomes, suggesting that pathologists should avoid overstating this mural nodule-like lesion.