Primary splenic carcinosarcoma with local invasion of chest wall: a rare case

Inhibition of chemotherapy-related breast tumor EMT by application of redox-sensitive siRNA delivery system CSO-ss-SA/siRNA along with doxorubicin treatment

Metastasis is one of the main reasons causing death in cancer patients. It was reported that chemotherapy might induce metastasis. In order to uncover the mechanism of chemotherapy-induced metastasis and find solutions to inhibit treatment-induced metastasis, the relationship between epithelial-mesenchymal transition (EMT) and doxorubicin (DOX) treatment was investigated and a redox-sensitive small interfering RNA (siRNA) delivery system was designed. DOX-related reactive oxygen species (ROS) were found to be responsible for the invasiveness of tumor cells in vitro, causing enhanced EMT and cytoskeleton reconstruction regulated by Ras-related C3 botulinum toxin substrate 1 (RAC1). In order to decrease RAC1, a redox-sensitive glycolipid drug delivery system (chitosan-ss-stearylamine conjugate (CSO-ss-SA)) was designed to carry siRNA, forming a gene delivery system (CSO-ss-SA/siRNA) downregulating RAC1. CSO-ss-SA/siRNA exhibited an enhanced redox sensitivity compared to nonresponsive complexes in 10 mmol/L glutathione (GSH) and showed a significant safety. CSO-ss-SA/siRNA could effectively transmit siRNA into tumor cells, reducing the expression of RAC1 protein by 38.2% and decreasing the number of tumor-induced invasion cells by 42.5%. When combined with DOX, CSO-ss-SA/siRNA remarkably inhibited the chemotherapy-induced EMT in vivo and enhanced therapeutic efficiency. The present study indicates that RAC1 protein is a key regulator of chemotherapy-induced EMT and CSO-ss-SA/siRNA silencing RAC1 could efficiently decrease the tumor metastasis risk after chemotherapy.

Primary Carcinosarcoma of the Spleen: A Rare Case Report of Incidental Finding after Splenic Trauma

Primary carcinosarcoma of the spleen is a rare, aggressive splenic malignancy. To date, seven cases have been reported in the literature. We report a first case of primary carcinosarcoma of the spleen in France. A 75-year-old woman with a medical history of hysterectomy for uterine adenocarcinoma presented with left hypochondrium pain following blunt abdominal trauma. A splenic mass was noted on computed tomography (CT) scan. A splenectomy was performed by laparotomy. Histology revealed a malignant mixed Mullerian tumor. The PET scan allowed us to confirm that it was a primary lesion of the spleen. She is currently undergoing adjuvant chemotherapy despite the tumor progression. The interest of this case lies in the rarity of primary carcinosarcomas of the spleen and the circumstances of its diagnosis.

Primary extragenital mixed malignant Mullerian tumour presenting as a painful splenic mass: A case report and review of the literature

BACKGROUND

Mixed malignant Mullerian tumours (MMMTs) are highly aggressive cancers that present at a late stage and are associated with a poor long-term prognosis. They are characterised by the presence of both epithelial and sarcomatous tissue types on histological examination and hence are known as biphasic tumours or carcinosarcomas. MMMTs almost always arise in the female genital tract (most commonly the uterus) but extragenital sites are also possible. Treatment options are limited and usually consists of surgery and adjuvant chemotherapy.

CASE SUMMARY

A 74-year-old woman presented with a 1-wk history of worsening left upper quadrant abdominal pain and a perisplenic mass on computed tomography (CT) scan. Features on imaging raised the possibility of a malignant process but were not diagnostic. Splenectomy was performed and histology confirmed the presence of a mixed malignant Mullerian tumour. A subsequent pelvic ultrasound identified another heterogenous cystic mass in the Pouch of Douglas without evidence of primary pathology in the uterus or adnexa. A second operation was performed for this with curative intent but previously-unknown widespread metastases were encountered at laparotomy. A biopsy of the pelvic mass confirmed it was also a MMMT with identical histological features to the perisplenic mass. There was no clinical or histological evidence of the MMMT having arisen primarily from the female genital tract. The patient subsequently suffered multi-organ failure and was palliated, succumbing to death on the 19^th post-operative day.

CONCLUSION

Primary extragenital MMMT arising from the spleen or peritoneum represents an atypical form of an already rare gynaecological tumour.

Mesenchymal Stem Cells: Miraculous Healers or Dormant Killers?

Mesenchymal Stem Cells (MSCs) are a heterogeneous population of fibroblast-like cells which maintain self-renewability and pluripotency to differentiate into mesodermal cell lineages. The use of MSCs in clinical settings began with high enthusiasm and the number of MSC-based clinical trials has been rising ever since. However; the very unique characteristics of MSCs that made them suitable to for therapeutic use, might give rise to unwanted outcomes, including tumor formation and progression. In this paper, we present a model of carcinogenesis initiated by MSCs, which chains together the tissue organization field theory, the stem cell theory, and the inflammation-cancer chain. We believe that some tissue resident stem cells could be leaked cells from bone marrow MSC pool to various injured tissue, which consequently transform and integrate in the host tissue. If the injury persists or chronic inflammation develops, as a consequence of recurring exposure to growth factors, cytokines, etc. the newly formed tissue from MSCs, which still has conserved their mesenchymal and stemness features, go through rapid population expansion, and nullify their tumor suppressor genes, and hence give rise to neoplastic cell (carcinomas, sarcomas, and carcino-sarcomas). Considering the probability of this hypothesis being true, the clinical and therapeutic use of MSCs should be with caution, and the recipients' long term follow-up seems to be insightful.