Actinomycosis: CT findings in six patients

Appendiceal actinomycosis mimicking malignant tumor: a rare case report

Introduction

Actinomycosis is an uncommon bacterial infection caused by Actinomyces bacteria that typically progresses slowly and leads to the formation of masses. Although it commonly affects the cervicofacial area, about 20% of cases occur in the abdominopelvic region. Because the disease can be mistaken for a tumour due to its infiltrative mass-like nature on imaging, over 90% of cases are only diagnosed following surgery and histological confirmation. This report describes a case of an appendicular mass, initially suspected to be a malignant tumour, but eventually diagnosed as appendiceal actinomycosis.

Presentation of case

Upon initial presentation, a 53-year-old woman with type II diabetes mellitus and no prior surgical history, displayed abnormal appendiceal uptake during a PET-computed tomography (CT) scan conducted for a suspected spinal tumour. Colonoscopy did not indicate any notable observations, and the patient chose to defer immediate action. Several months later, a CT scan revealed an increased mass-like appearance of the appendix compared to the previous PET-CT scan. After multidisciplinary discussions, a right laparoscopic hemicolectomy was recommended due to suspected malignancy. However, histological staining on microscopy confirmed actinomycosis originating from the appendix.

Discussion

Chronic appendicitis with radiologic features similar to appendiceal carcinoma, or abdominal masses located in the ileocecal area, in patients with or without a previous surgical history should raise suspicion of actinomycosis.

Conclusion

Appendiceal actinomycosis should be considered in the differential diagnosis in the aetiology of chronic appendicitis mimicking appendiceal carcinoma. Awareness and accurate diagnosis of appendiceal actinomycosis can prevent unnecessary extended surgery as was performed in this case.

Actinomycotic Abscess of Thyroid Gland in a 3-Year-Old Child

Actinomycosis is an atypical cause of infection in the head and neck area, especially in children. A rare incidence of actinomycosis, its nonspecific clinical signs that mimic other pathological conditions, as well as a complicated identification of microorganism lead to diagnostic delays in clinical practice. Besides an accurate diagnosis, it is of an utmost importance to pinpoint relevant predisposing factors, which might result in the infection. We present a clinical case of actinomycotic infection of the thyroid gland in the pediatric patient at our department.

Abdominopelvic actinomycosis: spectrum of imaging findings and common mimickers

BACKGROUND

Actinomycosis is a rare suppurative disease that may mimic other inflammatory conditions on imaging. Its invasive nature may lead to mass formation and atypical presentation thus making accurate diagnosis quite difficult.

PURPOSE

To describe the different aspects of abdominopelvic actinomycosis on cross-sectional imaging and indicate discriminative findings from other inflammatory or neoplastic diseases.

MATERIAL AND METHODS

In our study we analyzed 18 patients (15 women, 3 men; age range, 25-75 years; mean age, 50 years) with pathologically proved abdominopelvic actinomycosis. Contrast-enhanced abdominal computed tomography (CT) had been performed in all patients. Eleven patients had a history of using intrauterine contraceptive devices. Bowel site, wall thickness and enhancement degree, inflammatory infiltration, and features of peritoneal or pelvic mass were evaluated at CT.

RESULTS

The sigmoid colon was most commonly involved. Most patients showed concentric bowel wall-thickening, enhancing homogenously and inflammatory infiltration of pericolonic fat was mostly diffuse. In 11 patients, one or more pelvic abscesses were revealed, while a peritoneal or pelvic mass adjacent to the involved bowel segment was seen in three cases. Infiltration into the abdominal wall was seen in three cases while in one case there was thoracic dissemination.

CONCLUSION

Actinomycosis is related not only to long-term use of intrauterine contraceptive devices and should be included in the differential diagnosis when cross-sectional imaging studies show concentric bowel wall-thickening, intense contrast enhancement, regional pelvic or peritoneal masses, and extensive inflammatory fat infiltration with abscess formation.

Laryngeal actinomycosis

Actinomyces odontolyticus, a component of normal human flora, has been implicated in cervicofacial actinomycosis, which most commonly involves the perimandibular soft tissues and is characterized by slowly progressive abscess and sinus tract formation. Actinomycosis has rarely been reported to involve the larynx, and the imaging findings of laryngeal involvement have not been reported. We present a case of laryngeal actinomycosis with findings on computed tomography, magnetic resonance imaging, and positron emission tomography.

[The multiple thoracic actinomycosis in immunocompetent subjects]

L′actinomycose est une affection bactérienne granulomateuse, suppurative, étendue et chronique provoquée par la bactérie anaérobique gram positif Actinomyces israelii . La localisation thoracique est rare, elle peut simuler une pathologie néoplasique ou une tuberculose. Il s’agit d’un patient de 54ans sans antécédents pathologiques, qui s’est présenté avec deux tuméfactions pariétales basithoarciques droites, l’une antérieure et l’autre postérieure s’accompagnant d’une altération de l’état général. L’examen clinique ainsi que le bilan radiologique ont montré deux masses de la paroi thoracique et une atteinte parenchymateuse basale droite. L’examen anatomopathologique de la biopsie de la masse antérieure a montré des foyers d’actinomycose permettant d’établir le diagnostic d’actinomycose thoraco-pulmonaire. Un bilan immunologique s’est révélé normal. Le patient est alors mis sous traitement antibiotique à base d’amoxicilline protégée avec bonne évolution clinique et radiologique. Le but de cette observation est de rappeler les aspects radio-clinique, histologiques, thérapeutiques et évolutifs ainsi que les difficultés diagnostiques de cette affection.

Actinomycosis of cecum associated with entamoeba infection mimicking perforated colon cancer

Actinomycosis is a granulomatous disease caused by Actinomyces that mimics other intra-abdominal pathologies especially neoplasms. Correct diagnosis can be rarely established before radical surgery. On the other hand Entamoeba infection affects a considerable number of people worldwide. To our knowledge only one case has been reported to be affected by both organisms. We report a man who has been operated for a mass in the cecum mimicking a perforated colon cancer. Abdominal CT revealed a mass with features of an invading neoplasm. After radical surgery, definitive pathology revealed that the mass was due to actinomycosis associated with Entamoeba infection. The postoperative period was uneventful and the patient was on long-course antibiotherapy. It is important to consider actinomycosis especially in patients with intra-abdominal masses with unusual aggressiveness to prevent unnecessary surgery. However, surgery can be unavoidable especially in the presence of complicated disease or high index of suspicion for malignancy.

Pulmonary actinomycosis during the first decade of 21st century: cases of 94 patients

Background

Pulmonary actinomycosis is a chronic pulmonary infection caused by Actinomyces. Both improving oral hygiene and early application of antibiotics to the case of suspicious pulmonary infections result in changes in incidences and presentations of pulmonary actinomycosis. However, there are little reports dealt with the recent clinical characteristics of pulmonary actinomycosis. This study aimed to review the characteristics of pulmonary actinomycosis occurred during the first decade of 21st century.

Methods

This retrospective study was performed on 94 subjects with pulmonary actinomycosis diagnosed pathologically from January 2000 to December 2010 in 13 hospitals in Korea.

Results

The data of the study showed that pulmonary actinomycosis occurs frequently in middle to old-aged males (mean age; 57.7 years old) and that the most common symptoms are cough, hemoptysis, and sputum production. Various radiologic features such as the consolidation with central low attenuation (74.5%) and no regional predominance were also observed. Most of patients recovered completely with medical and/or surgical treatment, reaching approximately 98% cure rate.

Conclusions

The results demonstrate that pulmonary actinomycosis is one of the cautious pulmonary diseases. More importantly, in cases of persistent hemoptysis or for differential diagnosis from lung malignancy, our data have revealed that surgical resection appears to be a useful intervention and that radiologic diagnosis may not provide decisive information. These findings indicate that it is important for the clinicians to include pulmonary actinomycosis as one of differential diagnoses for refractory pulmonary abnormal lesions to the current usual management.

Tongue abscess with actinomycosis

Actinomycosis of the tongue is uncommon, but without proper treatment, it causes extensive tissue destruction. A mass that may mimic both benign and malignant neoplasms can be seen at clinical presentation and may mislead the diagnosis. Early diagnosis is critical but usually difficult with cultures or imaging. We report a patient who presented with a tumor-like deeply localized primary actinomycosis of the tongue with its magnetic resonance imaging findings.

Dormant primary cutaneous actinomycosis: Acute exacerbation after 16 years

Actinomycosis of head and neck are secondary to a nidus in the oral cavity and the aero-digestive tract. Primary actinomycosis without such predisposition is mostly due to trauma. We are presenting a case of this rare variant involving the forehead. The patient had a swelling over the forehead after a windscreen injury, which was asymptomatic for 17 years. However, 1 year ago, there was a repeat blunt trauma on the same site, but there was no breach of skin. Following this, the swelling became tender and started increasing in size. There was no response to a course of antibiotic and the patient had no concomitant history of any systemic illness. The swelling was excised and the biopsy revealed actinomycosis. This presentation of primary actinomycosis after such a long dormancy has never been reported before. This is yet another unusual presentation of actinomycosis, which is notoriously misdiagnosed owing to its rarity and numerous differential diagnoses.

Actinomycosis of the appendix mimicking appendiceal tumor: A case report

Actinomycosis is an uncommon chronic infectious disease. Common sites of involvement include the cervicofacial, thoracic and abdominopelvic regions. In abdominopelvic actinomycosis, the ileocecal region, including the appendix, is the most commonly involved site. In some reports, limited appendiceal actinomycosis has revealed a thickened appendiceal wall with peri-appendiceal inflammation as acute appendicitis or perforated appendicitis. We experienced pathologically confirmed intraluminal limited appendiceal actinomycosis without peri-appendiceal infiltration. Here, we report the computed tomography and ultrasound findings.

Pulmonary actinomycosis: a case undergoing resection through video-assisted thoracic surgery (VATS)

Actinomycosis is an uncommon disease, which is usually manifested as cervicofacial infection and related to poor oral hygiene or compromised immune function. Pulmonary actinomycosis is rare, but its diagnosis is changing due to its variable presentation and the similarity in appearance to other intrapulmonary diseases. Here we report an 80-year-old man with a solitary pulmonary nodule over the left upper lobe. Pulmonary neoplasm was highly suspected in this patient and thus resection of the mass was undertaken through video-assisted thoracic surgery (VATS). Histopathological examination demonstrated this patient had an Actinomyeces infection. While the application of VATS in patients with pulmonary actinomycosis has rarely been reported in literature, we conclude that VATS is valuable for the diagnosis and treatment of patients with undetermined pulmonary nodule(s).

Case 117: Actinomycosis of Left Kidney with Sinus Tracts

A 39-year-old Samoan man presented to the emergency department with fever, progressive weakness, and left flank pain of 1-month duration. For several months, he had also experienced progressive weight loss. There was no history of recent trauma, and he was not taking any medication. His medical history was notable for a large left groin abscess and left lower lobe pneumonia of unknown cause 1 year prior to the current admission. Furthermore, he had undergone exploratory laparotomy and gastric surgery for peptic ulcer disease approximately 10 years ago. Physical examination findings were positive for a tender firm mass in the left flank with no associated skin changes. Laboratory findings revealed an elevated white blood cell count of 18 x 10(9)/L. The urine cultures were negative. A computed tomographic (CT) image obtained 1 year prior to the current admission was unremarkable. CT of the abdomen and pelvis (section thickness, 5 mm) was performed after ingestion of 900 mL of 2% diatrizoate meglumine and diatrizoate sodium (Gastrografin; Bracco Diagnostics, Princeton, NJ). A 150-mL dose of iohexol (300 mg of iodine per milliliter) (Omnipaque; Nycomed, New York, NY) was administered intravenously at a rate of 4 mL/sec with a 70-second scan delay. Unenhanced CT images (not shown) did not reveal any areas of high attenuation.

A case of actinomycosis causing unilateral tonsillar hypertrophy

We report a case of unusual presentation of actinomycosis in the tonsil causing massive unilateral enlargement in a 78-year-old female. To our knowledge, only three cases of actinomycosis causing unilateral tonsillar enlargement have been published previously. Since this anaerobic organism is difficult to culture, the diagnosis is made by observing its associated sulfur granules in the biopsy specimen. In the present case, treatment consisting of tonsillectomy and antibiotic therapy (penicillin) for several days produced a good prognosis.

Computed tomographic demonstration of a fish bone in abdominal actinomycosis: report of a case

A 53-year-old man who had the habit of consuming fish bones was referred to our clinic because of a suspected malignant abdominal wall tumor. Computed tomography (CT) showed a mass (10 x 5 cm) in continuity with the transverse abdominal muscle, containing a small calcification. A laparotomy was performed with a preoperative diagnosis of an inflammatory mass due to fish bone penetration from the sigmoid colon. A fish bone, measuring 2.3 cm in length, was detected within the tumor by specimen radiography. The pathological findings demonstrated actinomycotic colonies. We herein present the first case of a CT demonstration showing a fish bone in an abdominal mass which was pathologically confirmed to be actinomycosis. Evidence of the presence of a foreign body is valuable for diagnosing inflammatory nodules such as actinomycosis and differentiation from malignancies.

Unusual causes of tubo-ovarian abscess: CT and MR imaging findings

Actinomycosis, tuberculosis, and xanthogranulomatous inflammation are rare but specific causes of tubo-ovarian abscess (TOA). TOAs with these causes are frequently misdiagnosed as ovarian malignancies due to their unusual appearances at computed tomography (CT) and magnetic resonance (MR) imaging. Tubo-ovarian actinomycosis frequently has a predominantly solid appearance. A linear, solid, well-enhancing lesion extending directly from the mass is a characteristic CT and MR imaging finding. Small rim-enhancing lesions in the solid part of the mass are also suggestive of actinomycosis. Tuberculous TOAs usually mimic peritoneal carcinomatosis from ovarian cancers. The granulomatous and fibrotic nature of this infection may be reflected in the CT and MR imaging appearances, which can help in differentiation. TOAs from xanthogranulomatous inflammation demonstrate more nonspecific imaging findings than actinomycotic or tuberculous TOAs, although multiple xanthogranulomas in the mass may be seen on MR images. Knowledge of these characteristics can help one make the correct diagnosis and treat the patients appropriately.

Actinomycosis mimicking recurrent carcinoma after Whipple’s operation

Actinomycosis is a rare, chronic, spreading, suppurative, granulomatous and fibrosing infection. Actinomyces are normal inhabitants of the oral cavity and gastrointestinal tract. They rarely cause disease and are seldom reported as pathogens. Herein, we reported on a 69-year-old male patient who had undergone Whipple’s operation due to ampulla Vater carcinoma, and became infected with actinomycosis at the pancreaticojejunostomy, which mimicked a recurrent malignancy. He was treated with radical resection of the mass at the pancreaticojejunostomy and had an uneventful postoperative course.

Renal actinomycosis mimicking renal tumor: case report

A 68-year-old man was admitted after fever and general fatigue with severe inflammatory signs and anemia. T1- and T2-weighted magnetic resonance imaging showed low- to isointensity and low-intensity tumor in the right kidney, respectively, suggesting renal actinomycosis. However, the right kidney was explored transabdominally because the possibility of renal malignant lymphoma could not be excluded. After nephrectomy, characteristic colonies of Actinomyces were seen microscopically, and the histologic diagnosis was renal actinomycosis. The patient was treated with antibiotics and made good progress after operation. This case highlights the importance of magnetic resonance imaging for the diagnosis of renal actinomycosis.

Foreign body-induced actinomycosis mimicking bronchogenic carcinoma

Actinomycosis is a slowly progressive infectious disease caused by an anaerobic and microaerophilic bacteria that colonizes the face, neck, lung, pleura and the ileocecal region. There have been a few cases of this disease which have involved in the lung but one very rare case has been reported. We report a case of foreign body-induced endobronchial actinomycosis mimicking bronchogenic carcinoma in a 69-year-old man. On admission, the patient presented with weight loss, cough and hemoptysis. The fiberoptic bronchoscopy revealed a soft tissue mass, with a partial occlusion of the left upper bronchus, which resembled bronchogenic carcinoma. Contrary to the first impression, the biopsy of the bronchus revealed the mass lesion to be an actinomycotic infection involving the bronchus. After the confirmation of the lesion, treatment with penicillin was initiated. The follow-up bronchoscopy revealed an aspirated fish bone at the site of infection. The foreign body was safely removed.

[Oral and cervicofacial actinomycosis. Presentation of five cases]

BACKGROUND

Actinomycosis is a suppurative and granulomatous chronic infectious disease caused by Actinomyces sp. and most commonly affecting the cervicofacial area.

AIM

To study the clinical characteristics of patients with actinomycosis, with regard to clinical history, presentation, method of diagnosis, treatment and follow up.

PATIENTS AND METHODS

A retrospective review was performed on all cases of microbiologically or histologically proven oral or cervicofacial actinomycosis.

RESULTS

Five patients were studied, 2 men and 3 women, 25-69 years old. Four patients had a history of surgical procedures and/or dental manipulations. Three patients showed the classic presentation of a lump and fistulization, and two patients presented intra-oral lesions. Four patients were diagnosed by cultures positive to A. israelii on microbiologic study and the remaining patient by cytologic detection of a sulfur granule. The first patient received the classic initial regimen of iv penicillin and 3 were treated with third-generation cephalosporins, continuing with oral amoxicillin during 12 months. Patient no.2 required a second surgical procedure. Patient no. 5, who had an exclusively oral process, received a short course of amoxicillin. There were no relapses during follow-up.

CONCLUSION

Actinomycosis is an uncommon disease. Establishment of the definite diagnosis requires a high index of suspicion and good clinical-microbiological collaboration. The classic course of iv penicillin and oral amoxicillin during 6-12 months is effective. For the acute phase treatment, iv penicillin can be replaced by third-generation cephalosporins.

Abdominopelvic actinomycosis involving the gastrointestinal tract: CT features

PURPOSE

To assess the computed tomographic (CT) features of abdominopelvic actinomycosis involving the gastrointestinal tract.

MATERIALS AND METHODS

CT scans were analyzed in 18 patients with pathologically proved abdominopelvic actinomycosis involving the gastrointestinal tract. Eight patients had a history of using intrauterine contraceptive devices. Bowel site, wall thickness, length, bowel involvement patterns, inflammatory infiltration, and features of peritoneal or pelvic mass, if present, were evaluated at CT.

RESULTS

Of the gastrointestinal tract, the sigmoid colon was most commonly involved (50%). All patients showed concentric (n = 15) or eccentric (n = 3) bowel wall thickening, with a mean thickness of 1.2 cm and a mean length of 8.3 cm. The thickened bowel enhanced homogeneously in nine patients and heterogeneously in the other nine. Inflammatory infiltration was mostly diffuse and severe. In 17 patients, a peritoneal or pelvic mass (mean maximum diameter, 3.2 cm) was seen adjacent to the involved bowel and appeared to be heterogeneously enhanced in most cases; infiltration into the abdominal wall was seen in four patients.

CONCLUSION

Actinomycosis should be included in the differential diagnosis when CT scans show bowel wall thickening and regional pelvic or peritoneal mass with extensive infiltration, especially in patients with abdominal pain, fever, leukocytosis, or long-term use of intrauterine contraceptive devices.

Abdominal actinomycosis following a forgotten intrauterine contraceptive device

A 57-year-old housewife presented with a 4-month history of anorexia and weight loss of 3 stone, abdominal distention and discomfort. Her medical history included diet-controlled diabetes mellitus, diagnosed 6 years previously, as well as long-standing hypertension and arthritis affecting the knees and hands. She took atenolol to control her blood pressure and naproxen for her arthritis. She had stopped smoking 6 years previously and drank minimal quantities of alcohol.

Rare presentation of actinomycosis as an abdominal mass: report of a case

PURPOSE

The purpose of this article was to report an unusual presentation of abdominal actinomycosis masquerading as a tumor.

METHODS

The patient was a 54-year-old male who presented with vague abdominal discomfort and a palpable left lower quadrant mass defined on CT scan. Multiple intraoperative core biopsies were nondiagnostic, and he underwent en bloc resection of the mass and adjacent organs for a presumed tumor.

RESULTS

Examination of tissue from deep within the excised specimen revealed sulfur granules diagnostic for actinomycosis.

CONCLUSION

Abdominal actinomycosis is an extremely rare infection that can mimic multiple disease processes and requires accurate diagnosis for successful therapy. This novel presentation and a review of the literature are reported.

Magnetic resonance imaging of actinomycosis presenting as pelvic malignancy

Pelvic actinomycosis is associated with long-standing use of an intrauterine contraceptive device and may present with clinical signs and symptoms of pelvic malignancy. Diagnostic imaging can confirm the presence of a pelvic mass and tissue infiltration but findings are often non-specific. We present a case of pelvic actinomycosis with tubo-ovarian abscess in which magnetic resonance imaging demonstrated lower signal intensity tissue on T2 weighted sequences than would be typical for pelvic malignancy or infection and was useful in confirming regression of pelvic disease in response to antibiotic therapy.

Ultrasound diagnosis and guided biopsy in renal actinomycosis

We report the case of a 45-year-old man with 3 months malaise, in whom ultrasound showed an atypical tumour of the right kidney. Ultrasound-guided fine needle biopsy led to a diagnosis of renal actinomycosis.

Atypical presentations of actinomycosis

BACKGROUND

Actinomycotic infections of the cervicofacial region are uncommon. Most major medical centers report approximately one case per year. Presenting clinical manifestations are confusing because they often mimic other disease processes. Diagnosis may be difficult due to a general lack of familiarity with the disease and the fastidious nature of the organism in culture. The cervicofacial manifestations of actinomycosis are varied, and a high index of suspicion is required to make an accurate and timely diagnosis.

METHODS

Retrospective chart review with the presentation of four unusual cases of actinomycosis were performed.

RESULTS

Two patients were initially seen with dysphagia from a tongue base mass. The third patient was initially seen with a 3-week history of worsening hoarseness and stridor. Examination revealed an ulcerative lesion of the left hemilarynx and pyriform sinus. All three patients were thought to have a neoplastic process. Diagnosis was made on histologic examination of a tissue biopsy. The fourth patient was initially seen with a buccal space mass that was draining externally. Culture of the purulent drainage revealed Actinomyces. In all four cases, symptoms resolved after appropriate antimicrobial therapy.

CONCLUSIONS

Actinomycosis of the head and neck, although rare, is an important entity to the otolaryngologist. A confusing clinical presentation combined with the fastidious nature of the organism make for a difficult diagnosis. A high index of suspicion is required to make an accurate diagnosis and institute the appropriate antibiotic therapy.

Retroperitoneal actinomycosis with intraperitoneal spread. Stellate pattern on CT

We report a case of pathologically proved actinomycosis that presented unusual computed tomographic (CT) features: a soft-tissue retroperitoneal mass encasing the adjacent ureter resulting in hydronephrosis and spreading into the intraperitoneal space with a stellate pattern. The role of CT in monitoring the response to antibiotic treatment is also discussed.

Pulmonary actinomycosis appearing as a "ball-in-hole" on chest radiography and bronchoscopy

A 40 year old diabetic man with pulmonary actinomycosis was admitted to hospital with recurrent haemoptysis. The chest radiograph showed an air meniscus in the left upper lobe, a rare presentation of pulmonary actinomycosis. Bronchoscopic examination revealed a mass in a cavity which has never been reported previously. He underwent lobectomy and the surgical specimen revealed sulphur granules, the typical pathological finding of actinomycosis, without evidence of fungal or mycobacterial infection.

Colonic actinomycosis: report of a case and review of the literature

Abdominal actinomycosis is a rare entity which presents some difficulty in establishing a correct preoperative diagnosis. We report herein the case of a 41-year-old woman who developed abdominal actinomycosis involving the left colon and the surrounding retroperitoneum. The patient, who had an intrauterine contraceptive device (IUCD) in situ, presented with left flank pain and the signs and symptoms of an intraabdominal mass, which was initially diagnosed as a neoplasm originating from the left colon or the retroperitoneal space. Thus, a left colectomy was performed, but the histopathological pathological diagnosis revealed abdominal actinomycosis. We evaluated the diagnosis and treatment of this disease in light of the knowledge acquired from the available literature on this rare entity.

Pediatric Actinomycosis of the Head and Neck

Actinomycosis is a rare soft tissue infection caused by a gram-positive, anaerobic bacteria. It is seen only approximately once a year in major medical centers, and is rarer still in the pediatric population. About 50% of all cases of actinomycosis involve the head and neck. The organism is very difficult to isolate in culture and the differential diagnosis is extensive, prompting one reviewer to name actinomycosis the “masquerader” of the head and neck. We review three cases of actinomycosis over the past ten years (1981–1990) at Texas Children's Hospital, Houston, Texas.

Mesenteric actinomycosis

We report a case of abdominal actinomycosis demonstrated on computed tomography (CT) as an isolated mesenteric mass with radiating linear and nodular densities. The lesion mimicked a mesenteric tumor with desmoplastic reaction. The clinical and radiological features of this uncommon entity are reviewed.

Multifocal thoracic actinomycosis simulating lymphoma

Thoracic actinomycosis is rare in the pediatric age group. We report the unusual case of a 10-year-old girl who presented with prolonged fever and weight loss with a neck mass and multiple pulmonary nodules resembling lymphoma. Open lung biopsy confirmed the diagnosis of actinomycosis and the symptoms and signs improved after treatment with cephalosporin. The pathogenesis and radiographic manifestations are briefly discussed.

Actinomycosis of the larynx

Actinomycosis is a disease characterized by a chronic suppurative and granulomatous process which tends to form multiple pyogenic draining sinus tracts. The most common site in which it occurs is the cervico-facial region, especially in the submandibular area. The exudates from the fistulous tracts usually contain yellow granules known as "sulfur granules," which can be considered as a hallmark of actinomycosis. We report a rare case of laryngeal actinomycosis which occurred in a 68-year-old male who had been irradiated 8 years before due to laryngeal carcinoma. During the admission, the patient was also diagnosed as being a myelodisplastic syndrome carrier. The patient was treated successfully with penicillin 10 million IU administered daily over 40 days. The etiologic agents, predisposing factors, diagnostic procedures, and available treatments are discussed, and the pertinent literature is reviewed herein.

Bronchial carcinoma following pulmonary and thoracic wall actinomycosis: report on one case with emphasis on CT findings

A case of bronchial carcinoma following pulmonary and thoracic wall actinomycosis is presented. Although pulmonary defense mechanisms are known to decrease with actimyces infection, the development of malignancy following chronic inflammation as in our case, has not in our knowledge been previously reported.

Pericardial actinomycosis with cardiac tamponade from a contiguous thoracic lesion

A case of acute pericardial tamponade due to actinomycotic infection is reported, in which computed tomography showed a mass adjacent to the heart and a pericardial effusion. The patient had aggressive medical treatment with penicillin and survived.