Psoas/iliacus muscle invasion from mucinous appendiceal neoplasm. Radiologic appearance and outcome of treatment in 3 patients

Pseudomyxoma retroperitonei secondary to appendiceal mucinous adenocarcinoma disguised as psoas abscess - A case report

INTRODUCTION AND IMPORTANCE

Appendiceal cancers are rare tumors, with mucinous cystadenocarcinoma accounting for 58 % of malignant appendiceal tumors. Mucinous cystadenocarcinomas are typically low grade but may lead to pseudomyxoma peritonei, causing accumulation of gelatinous material in the abdomen, often referred to as 'jelly belly'. In rare instances, the tumor may perforate into the retroperitoneal cavity leading to the phenomenon described as pseudomyxoma retroperitonei or extraperitonei.

CASE PRESENTATION

We describe the case of a young man presenting with a psoas abscess, initially treated with antibiotics. When the abscess failed to resolve, further testing was undertaken and revealed a diagnosis of mucinous adenocarcinoma with pseudomyxoma retroperitonei. The patient underwent a right hemicolectomy with debridement of the psoas abscess cavity. This case illustrates the need for a high index of suspicion for malignancy in the setting of recurrent or atypical psoas abscess.

CLINICAL DISCUSSION

Appendiceal mucinous neoplasms are found in <2 % of appendectomy cases. Due to the rarity of the pathology, they are often misdiagnosed as was in this scenario as a psoas abscess. Being in a tuberculosis-endemic area further complicated the diagnosis. Imaging and colonoscopy play a crucial in the proper, early diagnosis of these neoplasms that may present as a psoas abscess.

CONCLUSION

Appendiceal tumors initially presenting as psoas abscess can be misguiding, leading to dismissal of the underlying diagnosis. An appropriate diagnostic workup should be considered early in the disease course for prompt treatment of the condition.

Prevention of radiation enteritis by interposition of an intra-abdominal spacer before irradiation of an appendiceal tumour abscess drainage route

The initial presentation of a mucinous adenocarcinoma of the appendix can be a peri-appendicular abscess. The abdominal wall muscles can be invaded during radiological or surgical drainage. The management of such a tumour is complex. The resection of a drainage route can be uncertain and R1. In this case, further treatment with adjuvant radiotherapy may be necessary. One possible deleterious side effect of radiotherapy on the abdominal wall is radiation injury to the bowel. As a preventive measure, a spacer (here a breast prosthesis) can be interposed.

Mucinous Appendiceal Adenocarcinoma Penetrated the Quadratus Lumborum Muscle Posteriorly and Presented as Gluteal Abscess Managed Aggressively with Drainage Followed by Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Combined with Intraoperative Radiotherapy. a Case Report and Review of the Literature

Appendiceal mucinous adenocarcinoma is a term that was given for invasive appendiceal tumors. It is always present with pseudomyxoma peritonei which is a complex disease. These tumors have the tendency to surround the primary tumor then extend primarily and extensively all over the peritoneal cavity as the primary site of metastases. The invasion through the abdominal wall muscles is rare but the penetration and passing through these muscles to the subcutaneous tissue are extremely rare. A 62-year-old male patient known to have pseudomyxoma peritonei presented with gluteal abscess. After 2 weeks from the abscess drainage, the patient underwent cytoreductive surgery (CRS) combined with intraoperative radiotherapy (IORT) and hyperthermic intraperitoneal chemotherapy (HIPEC). He tolerated the operation well and discharged home in a good condition. Even with extensive appendiceal mucinous neoplasms presented with the penetration of the abdominal wall muscles, still aggressive management should be considered.