Late superinfection of postsurgical lymphocele

Clinical History

A middle-aged woman with history of radical hysterectomy, bilateral adnexectomy, omentectomy, lumboaortic and pelvic lymph node dissection for endometrioid ovarian carcinoma 9 months earlier was hospitalized because of recurrent fever (up to 39°C temperature) during three weeks. She denied associated symptoms and had no significant abnormalities found at physical examination.

Imaging Findings

After having completed adjuvant systemic chemotherapy, the patient was currently considered free from neoplastic disease. Previous medical history recorded the postoperative sonographic detection of bilateral small-sized (approximately 2 cm) pelvic fluid collections consistent with lymphoceles.
After empiric antibiotic treatment with minimal symptomatic relief, laboratory tests disclosed mild leukocytosis and increased C-Reactive Protein (120 mg/L). Considering the abnormal acute phase reactants without clear organ signs or symptoms, abdomino-pelvic CT was requested to investigate possible deep-seated infections. Multiplanar CT images (Fig. 1) revealed a bilobated fluidlike collection with thickened enhancing wall adjacent to a metallic surgical clip in the site of previously dissected obturator lymph node. The thickened inhomogeneously enhancing ipsilateral obturator internus muscle suggested contiguous infectious involvement. Venous filling defects indicating iliaco-femoral thrombosis are excluded.
The clinical and imaging diagnosis of infected lymphocele was confirmed by prompt regression of clinical, laboratory and imaging abnormalities after intensive antibiotic treatment.

Discussion

A well-known postoperative complication, lymphoceles are cyst-like collections of lymphatic fluid surrounded by a fibrotic wall without any epithelial lining, which result from iatrogenic injury to the lymphatic system during pelvic surgery. Uni- or bilateral lymphoceles are detected in up to 40% of patients after renal transplantation and surgical treatment of genitourinary, rectosigmoid or gynaecologic tumours, particularly when extensive lymph node dissection is performed for staging purposes [1-3].
Usually detected shortly (within 2 weeks) after operation, variable-sized lymphoceles are mostly asymptomatic and incidentally found on cross-sectional imaging, generally resolve spontaneously, and may occasionally (in nearly 20% of patients) persist up to one year after surgery. Sometimes associated with ipsilateral lower limb oedema and pain, lymphoceles may rarely become complicated by leg thrombosis, bladder compression or superinfection. As reported in sporadic case reports, delayed infection of pelvic lymphoceles is heralded by fever, low abdominal pain, and leukocytosis of uncertain origin regardless of the time elapsed since surgery. Infection is confirmed by increased leukocyte count and Gram-positive bacteriologic cultures from aspirated fluid [2-7].
As from the 2013 World Society of Emergency Surgery guidelines for management of intra-abdominal infections, early cross-sectional imaging, mostly with CT, is commonly requested to investigate suspected deep-seated and/or postoperative infections [8]. The CT or MRI imaging hallmark of an uncomplicated lymphocele includes a roundish or ovoid fluid-like collection adjacent to the blood vessels along the lymphatic course, characterized by thin regular walls and by the presence of metallic surgical clips. As this case exemplifies, superinfection is suggested by enlargement of a known lymphocele, by appearance of septations, internal inhomogeneity or by an abscess-like appearance with thickened enhancing walls [4-7].
Generally, lymphoceles require treatment only in a minority (6%) of cases. Currently, complicated or symptomatic lymphoceles may be successfully treated by percutaneous imaging-guided aspiration, catheter drainage with or without sclerotherapy. Alternatively, open surgical or laparoscopic drainage and internal marsupialisation may be sometimes performed [2, 7-9].

Differential Diagnosis List

Final Diagnosis

Superinfected pelvic lymphocele

URL:	https://www.eurorad.org/case/11670
DOI:	10.1594/EURORAD/CASE.11670
ISSN:	1563-4086