In this case report, we report a case of isolated hepatic actinomycosis (IHA) occurring in a 75-year-old female with no predisposing factors. Along with a eview of the literature, we will define the risk factors, clinical characteristics, diagnostic methods, and treatment of this infection.

Case presentation
A 75-year-old Caucasian woman of northern European descent presented with a 3-month history of night sweats, fevers (101-102°F nightly), chills, abdominal bloating, anorexia with 60 lb weight loss and early satiety. Her past medical history included hypertension, hypothyroidism, gastroesophageal reflux disease, diverticulitis, polymyalgia rheumatica, and a laparoscopic cholecystectomy in 1997. Current medications included hydroDIURIL,Toprol XL, Diovan, Synthroid, Prilosec, Plaquinil, and calcium supplementation. She denied any abdominal pain, nausea, vomiting, diarrhea or constipation and was able to tolerate per os diet despite her early satiety.

Physical examination revealed an elderly female who did not appear to be in any acute distress. Vital signs: temperature 100.7°F, pulse 54/bpm, respirations 20/min, blood pressure 116/56 mm/Hg, oxygen saturation 98% on room air. Abdominal exam revealed no palpable hepatosplenomegaly, guarding or rebound with normoactive bowel sounds. The rest of her exam was unremarkable. Laboratory studies demonstrated a leukocytosis of 12.8 103/mcL (4.0-10.0) and an absolute neutrophil count of 10.9 103/mcL (1.7-1.6). Hemoglobin level, hematocrit, platelet count and mean corpuscular volume were 8.2 gm/dL (12.0-16.0), 23.9% (36-48), 341 103/mcL (140-450) and 85 FL (82-100) respectively. The following liver chemistries were normal; serum glutamic oxaloacetic transaminase 17 IU/L (15-41), serum glutamic pyruvic transaminase 15 IU/L (10-15), total ilirubin 0.6 mg/dL (0.0-2.0) and direct bilirubin 0.2 mg/dL (0.0-0.8). Prothrombin time and international normalized ratio were 14.9 sec (8.0-12.5) and 1.30 respectively. There was an increase in alkaline phosphotase to 270 IU/L (27-120), tumor marker CA19-9 was 49.6 U/mL (0-35) and alpha fetoprotein was elevated to a level of 7.3 IU/mL (< 5.5). Albumin was low at a level of 1.8 gm/dL (3.2-4.8) as was serum protein 5.0 gm/dL (6.1-7.6). C-reactive protein, a marker of inflammation, was elevated to a level of 10.8 mg/dL (< 0.5).

The patient underwent imaging with an ultrasound of the liver and a CT of the abdomen. Both demonstrated a lesion in the posterior right lobe of the liver near the dome, measuring 6.9 x 7.4 cm, concerning for abscess and malignancy (Figure 1). This area was further characterized as not appearing fluid-like nor did it contain gas that would have allowed for confirmation of abscess. The patient was started on ciprofloxacin and flagyl for treatment of a potential abscess. Neoplasia remained a concern at this point, as several 1 cm. nodules were visualized at the lung bases and were concerning for metastatic disease. Gastroenterology, as well as infectious disease consults were obtained and the patient subsequently underwent liver core biopsy and aspiration. These tests revealed normal hepatocytes and organizing abscess respectively and both were negative for neoplasm. Unfortunately the specimens recovered from the core biopsy and aspiration were not stained for actinomycetes or sulfur granules, which could have lead to earlier diagnosis. Taking into consideration the patient’s presenting symptoms, multiple lung nodules and lack of positive tissue diagnosis, malignancy could not be ruled out. For definitive diagnosis the patient was to undergo a video-assisted thoracic surgical (VATS) lung biopsy to btain frozen section for culture and histochemical staining. The lung biopsy revealed fibrotic granulomata and were non-diagnostic for malignancy. A general surgeon then performed a laparotomy with biopsy of the liver. The liver specimen revealed neutrophilic microabscesses (Figure 2) containing gram-positive, filamentous, radially oriented bacteria in Brown and Brenn stained sections, consistent with actinomycosis (Figure 3). Characteristic sulfur granules were demonstrated on frozen section as well (Figure 4). The patient tolerated these procedures well and continued on a course of intravenous clindamycin for 15 days with transition to oral dosing lasting for a total of 6 months. She fully recovered and later imaging with CT demonstrated complete resolution of the liver abnormality.