Actimomycosis is a rare chronic bacterial infection of the central nervous system, and subdural actinomycoma is extremely rare. This case report brings to bear an uncommon association between subdural actinomycosis with chronic subdural hematoma. Subdural actinomycoma may present as a diagnostic conundrum and could be mistaken radiologically for either a subdural hematoma or an empyaema.

Hepatic actinomycosis with abdominal wall invasion was found by computed tomography (CT) in a 44-year-old woman. Occlusion of the main and right portal veins by the actinomycoma causing cavernous transformation was proven by angiography. Duodenobiliary reflux and communication between the biliary tree and the abscess were demonstrated by upper gastrointestinal radiography, percutaneous transhepatic cholangiogram, and CT. The imaging studies reflected the pathologic process of this disease. The unique feature of this case is that infection ascended through the duodenobiliary reflux; this should be considered one of the routes for the transmission of hepatic actinomycosis.

Actinomyces species are rare but treatable causes of CNS infection. Differentiation of actinomycosis from nocardiosis is crucial to the selection of appropriate antimicrobial therapy. A review of 70 cases of CNS actinomycosis was conducted in an effort to characterize clinicopathologic features and identify patients with a high risk of death from infection. Types of lesions included brain abscess (67%), meningitis or meningoencephalitis (13%), actinomycoma (7%), subdural empyema (6%), and epidural abscess (6%). Most infections developed from distant sites (lung, 19 cases; abdomen, four; pelvis, three) or contiguous foci (ear, sinus, and cervicofacial region, 21 cases). For nonmeningitic infection, signs and symptoms were generally those of a space-occupying lesion and were indistinguishable from the manifestations of other pyogenic infections except for a longer interval before diagnosis. Risk factors included dental caries; dental infection; recent tooth extraction; head trauma; gastrointestinal tract surgery; chronic otitis, mastoiditis, or sinusitis; chronic osteomyelitis; tetralogy of Fallot; and actinomyces infection of an intrauterine device. Optimal management combined adequate surgical drainage with prolonged antibiotic therapy (mean duration, 5 months). Overall mortality from treated infection was 28%; 54% of survivors had neurologic sequelae. Features correlated with a poor prognosis were disease onset greater than 2 months before diagnosis and treatment, no antibiotic treatment, no surgery, and needle aspiration drainage of abscess lesions.

A rare case of actinomycotic osteomyelitis with an intracranial granuloma is presented. The computerized tomography findings are probably the first of their kind. Both the site of osteomyelitis and clinical presentation are unusual. The pertinent literature is reviewed.

Six months of gastrointestinal embarrassment in a 31-year old male patient were coped with by transversostomy and subsequent anti-tumour drug and irradiation treatment. However, histology tests of a pseudotumour removed from the abdominal cavity proved the presence of actinomycosis (actinomycoma). Once adequate treatment had been started, the intraabdominal process began to recede thus permitting the transversostomy to be discontinued.

In vitro studies showed that ristomycin was the most active against actinomycetes causing actinomycosis as compared to benzylpenicillin, ampicillin, methicillin and lincomycin. The growth of the test microbes was inhibited by ristomycin in concentrations of 61--122 mg/ml. Since ristomycin was the most active against actinomycetes, its levels in the blood, parenchymatous organs, capsule and pus of actinomycomas of 5 rabbits infected wtih actino nycosis in the submaxillary area were determined. In the control healthy rabbit, the ristomycin levels were determined in the blood and organs. Ristomycin was administered intravenously in a single dose of 7000 mg/kg. Its concentrations in the animals were determined in 2.5 hours. The results of the experiments showed that ristomycin penetrated in therapeutic concentrations into the connective tissue capsule of actinomycoma. As for the other antibiotics tested earlier, they failed to penetrate this barrier. In 3 infected rabbits, ristomycin penetrated even the pus contained in actinomycoma. Ristomycin provides therapeutic concentrations in the disease focus and may produce a satisfactory therapeutic effect in treatment of actinomycosis.

Primary actinomycoma of the third ventricle has been reported to be a very rare form of central nervous system actinomycosis. Others have demonstrated actinomycotic-like colonies in colloid cysts of the third ventricle. We have confirmed these structures (HLS) in five colloid cysts and have demonstrated by various histochemical stains that they consist of desoxyribose nucleic acid, base protein and phospholipid. Ultrastructurally, they consist of amorphous to granular electron dense material, probably deposited on a lamellar substructure. On the basis of the available information, we believe that the lesions, previously reported as primary actinomycomas, are actually colloid cysts containing degenerative HLS. The possible origin of the hyphal-like structures is discussed.