Cervical Actinomycosis, a Throttling Compressive Myelopathy

Sir, Actinomycosis is a rare chronic granulomatous suppurative inflammatory disease caused by an anaerobic bacterium, Actinomyces israelii. Recently, many other similar organisms are recognized like A. Meyeri, A. Neuii, A. Turicensis, and A. Actinotignum, which cause infections in specific human body parts.[1] As per anatomical location, the disease can be divided into cervicofacial (55%), abdominopelvic (20%), thoracic (15%), and other (10%). Infection of the central nervous system (CNS) is rare, and that of the vertebral column with spinal cord compression is unknown.[2] A 24-year-old farmer came with a history of gradually increasing swelling in the suboccipital region for 6 years [Figure 1] and the restriction of neck movements for 4 years. He was initially diagnosed with craniovertebral junction (CVJ) bony tuberculosis and empirically received antitubercular therapy for 6 months. He presented to the emergency department with gradually progressive quadriparesis and breathing difficulty of 3 months. There was no associated fever, discharging sinuses from swelling, history of trauma, invasive procedures in recent past, or immune suppression. On neurological examination, he had spastic quadriplegia with tachypnea. He was evaluated with CT and MRI of the brain and spine with contrast imaging [Figure 2].Figure 1: Preoperative clinical images showing suboccipital swellingFigure 2: Radiological evaluation. (a) CT axial image of skull base showing bony destruction of foramen magnum. (b) CT brain contrast axial image showing enhancing mass involving cervical musculature. (c) MRI brain postcontrast images showing contrast enhancing lesion involving entire suboccipital musculature and foramen magnum with encasement of cervico-medullary junction. (d) MRI brain and CVJ postcontrast sagittal images showing contrast enhancing lesion in suboccipital region with dural enhancement encasing the cervico-medullary region with odontoid destruction. Extension of lesion in retropharyngeal area seen. (e) T2-weighted sagittal image of brain and upper cervico-dorsal spine showing the hyperintense suboccipital mass with hyperintesity extending from medulla to upper cervical spinal cord suggestive edemaGiven the mass effect and edema in the cervico-medullary junction and upper cervical cord, he underwent partial decompression of cervical mass, foramen magnum decompression, C1 arch excision, and C2 & C3 laminectomy. The mass was firm to hard and gritty [Figure 3a] with moderate vascularity. There were no clear planes noted from cervical musculature, and the bone appeared infiltrated with the lesion. Bone was soft, porous, and easy to nibble. The mass was easily dissected off the dura, and the thecal sac was lax and pulsatile at the end of bony decompression [Figure 3b].Figure 3: (a) Intraoperative image showing fibrous gritty mass involving cervical musculature. (b) Postbony decompression intact dura seen without any involvementThe histopathologic examination of the tissue sample was diagnostic, although cultures were negative for actinomyces. Histopathology revealed multifocal microabscesses with the center of each abscess showing basophilic granular actinomycotic colony with Splendore Hoeppli phenomenon [Figure 4a and b]. The colonies contained slender granulo-filamentous structures highlighted by Gomroi methenamine silver stains and were Grams positive [Figure 4c and d]. Surrounding these colonies, neutrophilic, eosinophilic, lymphoplasmacytic, and histiocytic infiltrate was noted.Figure 4: (a) Histopathological image showing the resected tissue having large colonies (asterix) within a suppurative abscess. (b) The colonies have thin eosinioophillic rim (Splendor Hoeppli phenomenon). (c) The colonies contain thin granular filamentous structures highlighted by Gomori methenamine silver stain. (d) The colonies contain thin granular filamentous structures highlighted by Grams stain. [a: H and E × Obj. 10; b: H and E × Obj. 20; c: GMS × Obj. 20; d: Grams stain × Obj. 20]He underwent a systemic clinico-radiological evaluation with ultrasound abdomen and X-ray chest when the diagnosis was confirmed to look for primary. His HIV status was negative, and his hemoglobin was 13.5 gm/dL; the total count was 10,300/mL. No other site of infection was noted. He was started on antibiotic therapy with 6 weeks of intravenous Penicillin G, followed by oral Clindamycin 300 mg QID for 6 months. At the time of discharge, he was able to move all limbs and turn around in bed. There was drastic improvement noted at 3 months follow-up when the patient came walking by himself with no breathing discomfort. Actinomycosis was originally discovered in cattle in 1877. Wolff and Israel diagnosed the first human infection as lung abscess by A. Israelii in 1891.[3] CNS infection with actinomycosis is reported in less than 5% of cases and is commonly in the form of brain abscess (67%), meningitis or meningoencephalitis (13%), and actinomycetoma (7%).[4,5] The incidence of spinal involvement with cord compression is a sporadic phenomenon. The reported case here has cervical actinomycosis with spinal cord compression leading to respiratory distress. It is the only case reported in the literature to date with such a presentation as per our knowledge. He had extensive cervical musculature involvement and bony destruction of the skull base and upper cervical spine. Also, the presence of edema in the medulla and upper cervical cord has not been reported previously. The meta-analysis of actinomycosis in 1987 reported the mean age at presentation was 36 years, with striking prevalence in males probably after injuries and disruption of mucosal or skin barrier in the field or workplaces.[4] The mean duration of symptoms was 2.1 months, with most patients having no detectable immune suppression other than a local breach of the mucosal barrier. In 33% of cases, the primary infection site could not be identified. The radiological images showed extensive cervical musculature involvement all around the skull base and upper cervical spine with bony destruction [Figure 2a] and spinal cord compression. The hyperintense signal changes on T2-weighted images of CVJ explain the breathing discomfort and motor weakness. According to us, the most probable reason for this edema is venous hypertension due to the lesion’s extradural compression. Also, the bone window on CT brain images showed a variable extent of bony destruction in the foramen magnum region.[5] The diagnosis of actinomycosis is mainly dependent on histopathological examination after either biopsy or surgical excision. It is challenging to grow these organisms in culture as the infections are polymicrobial. The organisms that reduce the concentration of oxygen in infected tissue tend to grow in cultures and suppress the growth of actinomyces and hence the reliance on histopathology for diagnosis.[6] It is a well-established fact that even though it is a chronic infection, a cure can be achieved with timely diagnosis and appropriate surgical excision or debridement and prolonged antibiotic therapy for the duration of 6 months to 1 year.[5] There is no specified duration of antibiotic treatment as per the currently available literature. Currently, antibiotic therapy is continued for 6 months to 1 year. Parenteral penicillin for 6–8 weeks, followed by an oral beta-lactam, is the current recommendation.[7] We plan to continue antibiotics for up to 6 months or more depending on the clinical and radiological response. At 3 months follow-up on Clindamycin, the patient walks unaided with minimal subtle motor weakness and without breathing discomfort. Cervical actinomycosis is a sporadic disease, especially with cord compression. Timely diagnosis, surgical excision, or debridement with prolonged antibiotic therapy lead to excellent neurological outcomes. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.