Splenic actinomycosis mimicking malignant lymphoma - A rare case of abdominal actinomycosis

ABSTRACT

BACKGROUND: Splenic Actinomycosis is a rare entity which usually presents as a difficult diagnostic case. It is a chronic granulomatous infectious disease, caused by Actinomyces which is commonly associated with history of abdominal surgery and manipulation. Majority of cases would present as an enlarging abdominal mass often mimicking malignant tumors.CASE PRESENTATION This paper presents a rare case of splenic actinomycosis in a 24-year-old Filipino female presenting as multiple splenic abscesses leading to gradual progressive ascites initially thought to be due to a malignant lymphoma. On physical examination, massive ascites and splenomegaly were the only abnormality appreciated. Initial radiologic imaging (x-ray, ultrasound, CT scan) revealed presence of multiple splenic nodules associated with extensive mediastinal and retroperitoneal lymphadenopathy as well as peritoneal extension/carcinomatosis (Figure 1 and 2). Splenic biopsy revealed presence of actinomyces (Figure 3).TREATMENT AND OUTCOME: Patient was started on amoxicillin 2.0 g per day for 24 months which led to a significant resolution of her massive ascites. Subsequent abdominal ultrasound showed gradual reduction in the hepatic and splenic size with resolution of splenic foci. Patient is currently on frequent follow-up.CONCLUSION: Splenic actinomycosis although extremely rare should be included as a differential diagnosis when presented with an unusual splenic mass or abscess on CT scan. Majority would mimic different forms of malignancy hence early histologic biopsy is usually needed to prevent unnecessary extensive and invasive surgical procedures. Radiologic and biochemical test are usually non-specific and not helpful with the establishment of the diagnosis. Although surgery remains to be the cornerstone for its management, prolonged antibiotic therapy might show promising results due to intensive closer follow up and accessibility to monitoring modalities for treatment response.