Postoperative peritoneal inflammatory granuloma mimicking peritoneal metastasis in a patient with breast cancer: a case report.

Am J Transl Res 2023;15(10):6247-6254 www.ajtr.org /ISSN:1943-8141/AJTR0152815 Case Report Postoperative peritoneal inflammatory granuloma mimicking peritoneal metastasis in a patient with breast cancer: a case report Young Jin Choi1, Sungmin Park1, Seung-Myoung Son2, Hae-Won Seo3, Jihye Hwang3, Se Joon Jung3, Young Duck Shin3 Department of Surgery, Chungbuk National University Hospital, Chungbuk National University College of Medicine, 1 Chungdae-ro, Seowon-gu, Cheongju 28644, South Korea; 2Department of Pathology, Chungbuk National University Hospital, Chungbuk National University College of Medicine, 1 Chungdae-ro, Seowon-gu, Cheongju 28644, South Korea; 3Department of Anesthesiology and Pain Medicine, Chungbuk National University Hospital, Chungbuk National University College of Medicine, 1 Chungdae-ro, Seowon-gu, Cheongju 28644, South Korea 1 Received August 8, 2023; Accepted September 22, 2023; Epub October 15, 2023; Published October 30, 2023 Abstract: Peritoneal metastasis from breast cancer is a relatively rare life-threatening condition. The gold standard for diagnosing peritoneal metastasis is a direct peritoneal biopsy. In this report, we describe an interesting case of peritoneal inflammation mimicking peritoneal metastasis in a patient with breast cancer, as confirmed by laparoscopic peritoneal biopsy. A 45-year-old woman with a history of right breast cancer presented with a peritoneal wall mass seen on an abdominal computed tomography (CT) in routine follow-up. She underwent right skin-sparing mastectomy with sentinel lymph node biopsy with direct to implant reconstruction 6 years prior and underwent right salpingo-oophorectomy 2 years before. Positron emission tomography-computed tomography (PET-CT) and abdominopelvic CT showed multiple enhancing nodules in small bowel mesentery and right peritoneal wall with a small amount of ascites, which led to a strong suspicion of peritoneal metastasis. After a multidisciplinary conference, the possibility of peritoneal seeding became doubtful. Laparoscopic biopsy was performed, and peritoneal wall mass biopsy was subsequently performed. Pathologic results showed no evidence of peritoneal metastasis of breast cancer. The peritoneal biopsy specimen revealed postoperative fibrosis and inflammation with some meal content. Although rare in breast cancer, peritoneal metastasis can produce a devastating outcome if left undiagnosed. Despite the imaging findings strongly suggesting metastasis, biopsy confirmation for the suspected lesion was necessary. This not only verifies true metastasis but also determines the treatment options available for the patient and thus unnecessary treatment can be avoided. Keywords: Breast carcinoma, peritoneal inflammation, peritoneal metastasis, acute peritonitis, laparoscopic biopsy Introduction Breast cancer is the most common malignancy found in women worldwide, and in Korea, it is the second most common cancer among women [1]. Although the incidence of locally advanced breast cancer has decreased and early breast cancer cases have increased, the incidence of metastatic breast cancer has not changed. Additionally, although there are advancements in multimodal therapies including intensive local treatment, chemotherapy, endocrine therapy, and targeted therapy, these have not produced significant changes in the prognosis of patients with breast cancer accompanied by distant metastasis [2]. The common sites of breast cancer metastasis are the bone, lung, liver, and brain, while metastasis to the peritoneal cavity is relatively rare. The reported incidence rates are 0.7-2.7% [3, 4]. Usually, peritoneal metastasis affects patients with gastrointestinal and gynecologic malignancies [5]. Most peritoneal metastasis Peritoneal granuloma mimicking metastasis versity Hospital, Republic of Korea. The patient provided informed consent for her treatment and agreed to the publication of the figures and data in this report. Case report A 45-year-old woman with a history of right breast cancer at the age of 40 years presented with a peritoneal wall and omental mass on CT image in routine follow-up. The CT scans of the abdomen and pelvis showed newly appeared Figure 1. Abdomen pelvis computed tomography findings (A-D) showed mulmultiple enhancing nodules in tiple enhancing nodules in the small bowel mesentery and the right peritoneal wall with a minimal amount of ascites and a suspicious rim-enhancing the small bowel mesentery nodular lesion in the right salpingo-oophorectomy site. That was suggestive and the right peritoneal wall of peritoneal metastasis. with a minimal amount of ascites and a suspicious rimfrom breast cancer is associated with metastaenhancing nodular lesion in the right salpingoses in other organs, and single metastasis to oophorectomy site. This was suggestive of the peritoneal cavity from breast cancer is unperitoneal metastasis (Figure 1). A PET-CT common [3]. It is reported that the peritoneal showed multiple hypermetabolic nodular lesimetastasis from breast cancer is developed ons in the left upper quadrant of the abdominal late and this late onset may be associated with mesentery, wall of the descending colon, right true delayed metastasis or late metastasis paracolic gutter, right pelvic cavity, and cul de detection [3-6]. This might not be associated sac (SUVmax = 8.4), suggesting peritoneal seedwith any specific symptom, and imaging modaliing. No gross hypermetabolic lesion was noted ties including computed tomography (CT) are in both breasts and axillae. Chest CT scan and limited in their ability to visualize localized peribone scan also showed no evidence of abnortoneal metastasis since they have low sensitivmality suggesting breast cancer recurrence ity for small-volume disease. Additionally, posi(Figure 2). tron emission tomography-computed tomograThe patient underwent right skin-sparing masphy (PET-CT) has a high rate of false positives tectomy with sentinel lymph node biopsy with in detecting peritoneal metastasis associated direct to implant reconstruction 68 months with tissue inflammation following diverse before the consultation. The tumor was diagmedical and surgical approaches [6]. The gold nosed as a well-differentiated invasive lobustandard in diagnosing peritoneal metastasis lar carcinoma, measuring 5.5 cm in diameter is direct peritoneal visualization, either by lapa(Figure 3A). On immunohistochemistry, the turotomy or laparoscopy. The peritoneal metastamor tested positive for the estrogen receptor sis from breast cancer shows a dismal progno(2+, 95%) and progesterone receptor (2+, 75%) sis, and early accurate detection is critical to and negative for C-erb-B2. The Ki67 proliferaavoid a life-threatening condition [3, 4]. tion index was 10%. Out of 5 sentinel lymph In this report, we describe an interesting case nodes sampled, one was revealed to have a of peritoneal inflammation with granulomas 3 mm macrometastasis on permanent patholmimicking peritone (...truncated)