Recurrent desmoid tumor arising from latissimus dorsi flap: A case report

We report a case of recurrent desmoid tumor arising from latissimus dorsi flap after lumpectomy for breast carcinoma. To our knowledge, this is the first case of desmoid tumor arising from the latissimus dorsi flap. Despite its benignity, desmoid tumor is often locally aggressive, therefore timely diagnosis and proper management are very important. Imaging and pathological diagnosis as well as treatment management are discussed. High clinical suspicion and multidisciplinary approach are essential for prompt diagnosis and management. Wide surgical resection is required, but there is no consensus regarding treatment due to limited data.

This study sought to highlight specific characteristics of breast and chest wall desmoid tumours on long-term follow-up by sequential MRI scans.Thirty-two breast MRI scans from six patients with chest wall or breast desmoid tumours followed up for up to 6 years were retrospectively reviewed. All patients underwent breast surgery prior to the development of the desmoid tumour. Five of the patients had reconstruction or augmentation using silicone implants. Two desmoids were treated primarily with surgery, three with medical means and one is under wait-and-see approach. On MRI, tumours appeared either oval and lobulated (chest wall) or spiculated with architectural distortion (breast). Chest wall desmoids demonstrated both an enhancing high-T2-signal component and a non-enhancing low-T2- signal component. The histologically defined phases during the course of desmoid tumours (progression, regression, residual disease) could be demonstrated by corresponding MRI changes in each of the components. Magnetic resonance imaging delineates the complex infiltrative features of chest wall and breast desmoid tumours. In tumours with a bright cellular enhancing and dark collagenous non-enhancing component, treatment response may be predicted by changes on serial T2-weighted sequences, beyond the tumour-dimension-based RECIST assessment alone.

To identify differential clinical and imaging findings between intra-abdominal desmoid tumors and peritoneal seeding that developed after surgery for colorectal cancer. 8 patients (9 desmoid tumors) and 11 patients (13 peritoneal seeding masses) were enrolled in our retrospective study. In patients with a desmoid tumor, initial T-stage, initial N-stage, and level of CEA at the time of surgery for intra-abdominal tumor were lower than in patients with peritoneal seeding (p=0.027, p=0.033, and p=0.017). The desmoid tumors were frequently located in the small bowel mesentery (p=0.018) and were larger at detection (p=0.041). Round or ovoid shapes on CT images were more frequently observed with the desmoid tumors (p=0.035). Stage of colorectal cancer, CEA level, and location, size, and shape of new intra-abdominal tumors can be helpful for differentiating between intra-abdominal desmoid tumors and peritoneal seeding in patients with a history of colorectal cancer surgery.

Objective of our study was to evaluate the treatment outcomes of extra abdominal fibromatosis in patients who were treated in our setup and determine the recurrence patterns. It is retrospective cohort of 15 patients that were treated in section of Orthopaedics, department of surgery, Aga Khan University hospital, Karachi from January 1990 to December 2015. It included all adult patients of age >18 years with biopsy proven extra abdominal aggressive fibromatosis. Out of 15 patients, there were 7 males (46.7%) and 8 females (53.3%). Median age was 22 years. Majority of patients [10 (66.6%)] had upper limb lesion. On initial biopsy we had 11 (73.3%) cases of primary fibromatosis while 2 (13.3%) were recurrent and 2 (13.3%) were spindle cell carcinoma. The median (IQR) follow-up time of the participants was 3 (2-3) months. Complications occurred in 8 (53.3%) patients. A significant difference was observed in the haemoglobin levels before and after surgery with a mean difference of 2.74 (p-value<0.001). Recurrence of disease occurred in 4 (26.7%) patients and all of these patients who had recurrence underwent 2nd surgery versus 1 of the participants who had second surgery without recurrence and this was a significant difference (p value <0.004). Extra abdominal fibromatosis is commonly found among younger age groups, affecting females more as compared to males. Less than half of the patients had recurrence of disease in our study and intra-operative and postoperative complications are common surgical outcomes and our study results are compatible with previously reported literature.

Gain-of-function mutations in the beta-catenin gene (CTNNB1) drive genomic instability within different cancers. However, it is unclear whether alterations in beta-catenin signaling can still lead to chromosomal rearrangements in neoplasms without metastatic potential. Here, we report a unique case, whereby a desmoid tumor of the scalp contains a missense mutation in CTNNB1. This mutation is located at the T41 phosphorylation site—previously reported to be necessary for proper beta-catenin degradation. Online database analysis then revealed that our mutation is likely causative of many different cancers and also absent in the healthy public. Karyotyping of the desmoid tumor cells then showed complex chromosomal changes in 16 out of 20 cells examined. To treat this patient, we surgically removed both the neoplasm and underlying calvarium and then successfully reconstructed the skull and scalp. Taken together, our data suggest that increased beta-catenin signaling can lead to genomic instability in the absence of metastatic potential.

Three distinct mutations involving the CTNNB1 (beta-catenin) gene have been identified in the vast majority of desmoid-type fibromatosis tumors, which cause activation of the Wnt signaling pathway and impact prognosis. This study examines whether the different CTNNB1 mutants (T41A, S45F) occurring in DTF tumors differentially affect Wnt signaling activity, which might explain the different disease course between DTF patients harboring different CTNNB1 mutations. Real-time polymerase chain reaction (RT-PCR) on 61 formalin fixed paraffin embedded DTF samples with known CTNNB1 status was used to measure the relative mRNA expression level of Wnt target genes AXIN2, DKK1 and CCND1. Additionally, publicly available mRNA expression data retrieved from the Gene Expression Omnibus of 128 DTF samples were used for an unsupervised cluster analyses based on the expression of a selection of Wnt targets. No statistically significant difference in relative expression levels of Wnt target genes AXIN2, DKK1 and CCND1 was identified between either CTNNB1 wild-type, S45F or T41A mutated DTF samples. Moreover, the hierarchical cluster analyses using selected Wnt targets did not discriminate between different CTNNB1 mutation types. No differences in the expression levels of Wnt target genes were observed between the different CTNNB1 mutation types in DTF tumors. Further studies are needed to decipher the mechanism accounting for the diverse disease courses between DTF patients with different CTNNB1 variants.