The first incidence of actinomycosis in humans was defined as a fungal infection by Von Langenbeck in 1845. In 1891, Israel and Ponfick described the anaerobic nature of Actinomyces. In 1960, Waksman demonstrated that Actinomyces were gram-positive bacteria[5].
The cervical region, and particularly the submandibular area, is the main region that is affected in actinomycosis. Diagnosis is based on fine-needle aspiration cytology and biopsy. Computed tomography and magnetic resonance imaging can be useful for determining the size of the lesion. It is known that this disease has a tendency to resemble carcinoma and tuberculosis[5].
Figure 2: Identification of osteomyelitis and the location of the abscess in the mandible (HE, x40).
Figure 3: Filamentous bacilli stained GMS positive (GMS; x630).
Actinomycosis infections usually involve the cervicofacial, thoracic, and abdominopelvic regions as well as the cranionervous system, and no person-to-person transmission has been documented. Actinomycotic osteomyelitis mainly occurs due to adjacent tissue infection, but it can also be observed in some fractures or in hematogenous spread. Cutaneous sinus tracts usually develop[6].
Radiologically, it is difficult to differentiate mandibular osteomyelitis from other neoplasias. Therefore, in such cases, bone lesion biopsy is important for determining the nature of the lesion.
Ultrasound is the primary preferred imaging technique that is used routinely for the neck region due to lack of side effects and rapid implementation. During ultrasound, fine needle aspiration cytology can be performed to achieve a pathological diagnosis. Computed tomography is more effective for identifying abscesses and surrounding anatomic structures; however, it may not fully reveal specific masses in soft tissue. Branchial cleft cyst, lymph node metastasis, inflammatory lymphadenopathy, and vascular tumors are the differential radiological diagnoses[7].
Clinical diagnosis is difficult due to non-specific findings. Differential diagnoses include many diseases, from tumors to chronic diseases (carcinoma, tuberculosis, and others). Cases are diagnosed based on the presence of bacteria with a positive culture and biopsy. Pathological diagnosis is simpler and less invasive using fine-needle aspiration cytology. Yellow sulfur granules are typically observed in the purulent material, which may be helpful in diagnosis. The drained material can be cultured; however, less than 50% of the cultures are positive. Through the use of microscopy, colonies can be observed as filamentous bacilli with granular centers and a radial distribution[7]. We diagnosed the mandibular mass as mandibular osteomyelitis caused by actinomycosis by observing positive filamentous bacilli with GMS, PAS, and Gram stain. Histochemical analysis of cervicofacial lesions can be used to determine the possibility of actinomycosis infection.
Bartkowski et al. reported 15 cases with actinomycotic osteomyelitis in the mandible. While nine of those cases were primary actinomycotic inflammation of the mandible, mandibular fracture or mandibular resection was observed in six of them. The authors reported that they obtained the diagnosis on the basis of bacteriological and histopathological tests[8]. Additionally, in our case, oral hygiene was poor, and there were healed wounds and fistula scars on the skin. Our case differed from the other published cases because the lesion in our case had a mass image, and similar cases were not found in the literature. We used histopathology and histochemistry to achieve a diagnosis, and our outcome emphasized the importance of histopathology for diagnosing such lesions.
As a result, it is suggested that actinomycosis infections can mimic malignancy because in our case, the mass occurring in the mandible was clinically and radiologically evaluated primarily as a tumoral formation in the preoperative period. Ultrasound-guided fine-needle aspiration or biopsy will be very valuable for preoperative diagnosis of cervicofacial masses. Actinomycosis should be considered in patients with cervicofacial lesions because it may mimic malignancy. The removal of the infected bone, careful debridement of dental remains, and long-term intravenous and oral antibiotic therapy will be effective in the treatment of mandibular osteomyelitis caused by actinomyces.
1) Figueiredo LM, Trindade SC, Sarmento VA, de Oliveira TF, Muniz
WR, Valente RO. Actinomycotic osteomyelitis of the mandible:
An unusual case. Oral Maxillofac Surg. 2013;17:299-302.
2) Kingdom TT, Tami TA. Actinomycosis of the nasal septum in
a patient infected with the human immunodeficiency virus.
Otolaryngol Head Neck Surg. 1994;111:130-3.
3) Baliga S, Shenoy S, Wilson G, Katara V. An unusual case of
actinomycosis. Ear Nose Throat J. 2002;81:44-5.
4) Ozcan C, Talas D, Görür K, Aydin O, Yildiz A. Actinomycosis of
the middle turbinate: An unusual cause of nasal obstruction. Eur
Arch Otorhinolaryngol. 2005;262:412-5.
5) Vigliaroli E, Broglia S, Iacovazzi L, Maggiore C. Double
pathological fracture of mandibula caused by actinomycotic
osteomyelitis: A case report. Minerva Stomatol. 2010;59:507-17.
6) Acevedo F, Baudrand R, Letelier LM, Gaete P. Actinomycosis:
A great pretender. Case reports of unusual presentations and a
review of the literature. Int J Infect Dis. 2008;12:358-62.