
==== Front
J Neurosurg Case Lessons
J Neurosurg Case Lessons
J Neurosurg Case Lessons
Journal of Neurosurgery: Case Lessons
2694-1902
American Association of Neurological Surgeons

10.3171/CASE24210
CASE24210
CraniofacialCraniofacialInfectionInfectionTumorTumorTechniqueTechniqueDiagnostic-TechniqueDiagnostic TechniqueCase Lesson
An invasive and diffuse cranial actinomycosis with a dura-based mass mimicking a brain tumor: illustrative case
Gebrewahd Dejen T MD 1
Laeke Tsegazeab MD, PhD 1
Wendimagegnehu Eyob Z MD 1
Shiferaw Mestet Y MD 5
Tefera Tesfaye G MD 2
Aliye Ilili A MD 2
Robele Taye J MD 3
Mekuria Bereket H MD 1
Berga Anteneh E MD 4
Mendere Surafael M MD 1
Abelti Sebboona B MD 1
1 Department of Surgery, Neurosurgery Division, Addis Ababa University, Addis Ababa, Ethiopia
2 Department of Radiology, Neuroradiology Unit, Addis Ababa University, Addis Ababa, Ethiopia
3 Department of Pathology, Myungsung Christian Medical Center, Addis Ababa, Ethiopia
4 Department of Internal Medicine, Infectious Disease Unit, Addis Ababa University, Addis Ababa, Ethiopia
5 Department of Surgery, Debre Tabor University, Debre Tabor, Ethiopia
Correspondence Dejen T. Gebrewahd: Addis Ababa University, Addis Ababa, Ethiopia. dejentek2005@gmail.com.
INCLUDE WHEN CITING Published September 23, 2024; DOI: 10.3171/CASE24210.

Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

23 9 2024
23 9 2024
8 13 CASE2421024 3 2024
15 7 2024
© 2024 the authors
2024
the authors
https://creativecommons.org/licenses/by-nc-nd/4.0/ CC BY-NC-ND 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

BACKGROUND

Actinomycosis is a chronic suppurative infection caused by non–spore-forming, anaerobic, and filamentous gram-positive bacteria. Primary central nervous system involvement is rare, with no specific clinical features, causing a clinical diagnostic dilemma. Imaging can help in localizing and characterizing the lesion; however, a definitive diagnosis relies on culture and/or histopathology.

OBSERVATIONS

The authors describe a 29-year-old male farmer with a rare case of invasive and diffuse cranial actinomycosis with a dura-based mass mimicking a brain tumor. Brain magnetic resonance imaging showed a moderately enhanced right frontoparietal infiltrative dura-based mass with marked thickening of the skull and multiple scalp actinomycotic abscesses. He underwent microsurgical excision of the mass, orbital decompression, and debridement of the scalp abscess. Histopathology confirmed actinomycosis, and his postoperative course was uneventful.

LESSONS

Invasive and diffuse cranial actinomycosis with a dura-based actinomycetoma is a rare presentation that poses a diagnostic challenge due to its nonspecific manifestations. Imaging is helpful in localizing and characterizing the lesion; however, histopathology remains the gold standard for diagnosing actinomycosis. A high index of suspicion is also warranted in patients with predisposing factors to promote an early diagnosis and the initiation of appropriate treatments to improve functional recovery and limit residual deficits.

https://thejns.org/doi/10.3171/CASE24210

brain tumor
CNS actinomycetoma
cranial actinomycosis
ABBREVIATIONS

CNS = central nervous system
CT = computed tomography
HIV = human immunodeficiency virus
MRI = magnetic resonance imaging.
==== Body
pmcActinomycosis is a rare, infiltrating, slowly progressing granulomatous and suppurative infection caused by non–spore-forming, non–acid-fast, anaerobic, filamentous gram-positive bacteria called Actinomyces.1 The bacteria are found as normal flora in the human oral cavity, gastrointestinal tract, and urogenital tract.1, 2 The disease is usually caused by the introduction of bacteria due to anatomical disruption of the skin and/or mucosa.1 Immunocompromised patients, including those who have received organ transplants, those with cancer who are undergoing chemotherapy or radiation, those with human immunodeficiency virus (HIV) infection or chronic alcohol abuse, or those who are smokers with poor dental hygiene, are predisposed to contracting actinomycosis.1, 2Actinomyces israelii is the most commonly isolated species, followed by Actinomyces meyeri. The cervicofacial region is more frequently involved, followed by the thoracic, abdominopelvic, and rarely the extremities.2, 3

Primary central nervous system (CNS) involvement is rare; however, local spread from odontogenic infection or hematogenous dissemination from distal infections such as a pulmonary or abdominopelvic focus has been described.4 Actinomycosis involving the scalp manifests with indurated skin lesions or tumefaction with abscesses and sinuses draining pus that contains the granule of the causative organism.5 Intracranial actinomycosis appears as a brain abscess, subdural empyema, or epidural abscess and often as parenchymal or leptomeningeal masses.1, 2, 5, 6 Clinical manifestation depends on the anatomical site involved and the degree of invasiveness; however, most patients present with headaches and focal neurological deficits. This varied and nonspecific clinical manifestation results in late recognition and difficulty in distinguishing from possible differential diagnoses, including many neoplastic diseases and chronic granulomatous infections such as nocardiosis, fungal infections, or tuberculosis.3, 7

There is no specific image characteristic of an actinomycotic infection or granuloma involving the CNS and cranium.7 Magnetic resonance imaging (MRI) and computed tomography (CT) scans can help to determine the site, size, and extent of involvement, signal characteristics, and skull changes, respectively.7, 8 Histopathological identification of Actinomyces from the affected tissue or abscess confirms the diagnosis.1, 8 Gram stains are more sensitive than culture due to the microaerophilic or anaerobic character of Actinomyces.1, 3 However, the yield from culture may be improved with strict anaerobic processing and prolonged incubation.1, 8 Treatment of cranial or CNS actinomycosis includes microsurgical excision, debridement, drainage, or aspiration of pus when indicated, and prolonged therapy with beta-lactam antibiotics, usually penicillin G, and often other alternatives such as amoxicillin, tetracycline, erythromycin, and ceftriaxone.1–4, 9, 10

Here, we report a rare and diagnostic challenge of invasive and diffuse cranial actinomycosis with an intracranial dura-based mass mimicking a brain tumor.

Illustrative Case

A 29-year-old male farmer from a remote rural area came to our referral clinic after presenting with the progressive onset of scalp swelling, bilateral orbital protrusion, visual deterioration, and intermittent right-sided headaches of 6.5 years’ duration. He later developed worsening headaches, right-eye visual decrement, complete vision loss in the left eye, and multiple scalp eruptions with episodic purulent discharge for the last 8 months. The patient denied fever, cough, weakness, other site infections, previous cranial surgery, craniofacial trauma or dental procedures, cardiac illness, treatment of cancer, or known chronic medical illness.

The physical examination showed an adult man who appeared chronically ill but had normal vital signs. During the head and general examination, it was observed that the scalp was grossly disfigured with nodular, nontender areas that had multiple small sinus tracts. On squeezing, the sinus tract drained with minimal discharge, simulating thin pus. Additionally, there were signs of poor hygiene with multiple dental cavities, and he had bilateral exophthalmos with ophthalmoplegia (involvement of the eye muscles). A pertinent neurological examination demonstrated that he was fully awake and oriented with a Glasgow Coma Scale score of 15, no light perception in the left eye, and decreased visual acuity in the right eye. Funduscopic examinations revealed bilateral papilledema and left optic nerve atrophy. He had grade 4/5 strength in his left upper-limb muscle group. All other neurological and systemic examinations were unremarkable.

Investigations

Laboratory Tests

Initial blood tests revealed mild anemia with a hemoglobin level of 12 g/dL and a hematocrit of 36%. There was also a slight increase in the erythrocyte sedimentation rate and C-reactive protein. However, other test parameters, such as electrolytes, organ functions, HIV tests, random blood sugar, and hemoglobin A1C, were unremarkable.

Imaging Findings

MRI of the head was conducted, revealing a dura-based mass on the right frontoparietal area, measuring 2.3 × 3.5 × 3.7 cm. It appeared isointense on T1-weighted MRI and hypointense on T2-weighted MRI, accompanied by significant perilesional edema causing mass effect and no significant diffusion restriction on diffusion-weighted imaging/apparent diffusion coefficnient. The lesion showed some enhancement after contrast, along with noticeable and widespread meningeal involvement. Additionally, there was diffuse thickening of the bilateral frontotemporoparietal and sphenoid bone, extensive infiltration of the scalp soft tissues with varying signal intensity, and the presence of multiple ring-enhancing lesions in an area. Furthermore, bilateral orbital protrusion due to soft tissue infiltration and thickening of the orbital wall, more prominently observed on the left side, were also noted (Fig. 1). FIG. 1. Preoperative brain MRI showing a T1-isointense (A), T2-hypointense (B), right frontoparietal mass with surrounding marked perilesional edema, diffuse bilateral skull thickening, a dura-based infiltrative mass with modest postcontrast enhancement and pachymeningeal involvement (C), and extensive scalp infiltration with an area of multiple ring-enhancing lesions (D). Arrows in A, B, and C indicate dural-based infiltrative mass, and arrows in D indicate scalp abscess.

Head CT with bone window showed diffuse, asymmetric thickening and sclerosis of the bilateral parietal, frontal, temporal, and sphenoid bones with marked sclerosis, a solid-type periosteal reaction, and an inner table edge irregularity. The lesion involved the orbital roof and lateral walls bilaterally, with a mass effect on the intraorbital structures and protrusion of the eye globes bilaterally. There was also a diffuse, significant thickening of the bilateral frontal, parietal, and temporal scalp soft tissue (Fig. 2). FIG. 2. Preoperative head CT with bone window demonstrating diffuse and asymmetric thickening of the bilateral parietal, frontal, temporal, and sphenoid bones with marked sclerosis, coronal suture diastasis, and inner table edge irregularity (A and B). Arrows indicate areas of marked calvaria thickening.

Surgical Procedure and Findings

A skin incision and craniotomy involving the much-thickened right frontotemporoparietal region were performed. There was very firm, fibrotic, and nodular scalp soft tissue, which was yellowish to whitish in appearance, with multiple pockets filled with purulent content. Accessible scalp abscesses and infiltrated parts were drained and debrided, and the fistulous sinus tract was excised. The skull was thick and hard, with multiple pits and an obliterated diploic space. The frontotemporoparietal bone flap was elevated, the lateral orbital wall and part of the roof were drilled, and orbital decompression was performed.

Multiple yellowish-white epidural micronodules with a firm to hard consistency were noted and subsequently debrided. A dura-based infiltrative actinomycotic granuloma was meticulously identified from the normal brain parenchyma, dissected, and excised microsurgically. Microsurgical gross-total excision of the infiltrative meningeal-based right frontoparietal actinomycetoma and debridement, abscess drainage, and sinus tract excision of the involved scalp were done. Hemostasis was then secured with bipolar electrocautery and Surgicel (Shalya TURoSeal). A bone flap was replaced after a duraplasty. An excisional biopsy sample was taken from each lesion, and samples from the abscess were sent for histopathological and microbiological analysis.

Postoperative Course and Treatment

The patient tolerated surgery well, and his overall postoperative hospital stay was uneventful. Control brain MRI and CT were performed on his 1st postoperative day, demonstrating gross-total excision of the dura-based mass (actinomycetoma) and decompression of the right orbit (Fig. 3). Once the diagnosis of actinomycosis was confirmed, the patient started high-dose intravenous ceftriaxone, and, after 4 weeks, he was discharged home on a regimen of oral amoxicillin for 12 more weeks. At the time of discharge, subjective and objective improvement iin right-eye visual acuity, headache, and proptosis of the right eye were noted. A follow-up visit at 6 months postsurgery showed improved vision and decreased scalp soft tissue swelling, the sinus tract had disappeared, and he claimed that he had started doing daily activities as previously. FIG. 3. Postoperative control MRI of the brain with contrast (A; the arrow demonstrates the actinomycotic granuloma cavity after resection) showed gross-total excision of the infiltrative dura-based mass (actinomycotic granuloma). Postoperative head CT (B;the arrow demonstrates orbital decompression) demonstrated a well-decompressed right orbit.

Culture and Gram Stain Results

Gram staining of the exudate revealed filamentous gram-positive bacteria; however, an acid-fast bacillus test had unrevealing results, and no organism was identified in the culture.

Histopathology Results

The specimen grossly appeared gray, whitish to yellowish, irregular, and friable and was firm in consistency, showing multiple micronodularities. A microscopic study of the biopsy from the scalp abscess, epidural micronodules, and dural mass showed similar findings. It demonstrated a scattered cluster of sulfur granules, which are characteristic of actinomycosis, composed of colonies of Actinomyces with branching filaments. The periphery of the granule contained a club-shaped configuration surrounded by fibrosis, dense mixed inflammatory infiltrates including polymorphonuclear neutrophils, histiolymphocytes, macrophages, and multinucleated giant cells, suggesting a chronic suppurative granulomatous inflammatory process due to actinomycosis (Fig. 4). FIG. 4. Histopathological study showed a whitish to yellowish, irregular, and friable mass with multiple micronodularities (A). Microscopically, a scattered cluster of sulfur granules (B, original magnification ×2.5) is composed of colonies of Actinomyces with branching filaments (original magnification ×20 [C] and ×40 [D]). The periphery of the granule contains a club-shaped configuration surrounded by fibrosis, dense mixed inflammatory infiltrates, and xanthogranulomatosis. Hematoxylin and eosin staining.

Patient Informed Consent

The necessary patient informed consent was obtained in this study.

Discussion

Observations

Actinomycosis is an insidious bacterial infection that has the tendency to spread contiguously by crossing facial planes or hematogenously from systemic infection.11 The scalp can be involved in cases of secondary actinomycosis, but usually it is focal.5 The presentation can range from a mild form, such as a scalp induration, to a severe one, including multiple scalp actinomycotic granulomas and an abscess with draining sinus tracts, which aligns with our patient’s presentation. An aggressive form of scalp actinomycosis has been reported.5 However, our case appears unique due to its more extensive and infiltrative nature and the fact that it involved the scalp, anterior skull base, and calvaria diffusely.

Primary skull base and vault involvement is extremely rare and can present secondarily as a direct extension of cervicofacial actinimycosis.9 McCann et al. reported a case of extensive actinomycosis involving the skull base and temporal bone due to extension from a facial actinomycotic infection.9 A case of localized recurrent actinomycotic osteomyelitis involving the frontal skull vault with underlying epidural and subdural collection haas also been reported.12 Skull involvement manifests as lytic features or reactive sclerosis, as in our patient. Most of the reports from the case series have described focal skull lesions and diffuse bilateral involvement as being rare. However, our patient showed extensive skull involvement, with bilateral diffuse thickening of the frontotemporoparietal skull vault and anterior skull base, rendering a unique and atypical presentation compared with cases reported so far.

CNS involvement is reported in < 5% of all Actinomyces infections.8 The frequent presentation is a brain abscess followed by leptomeningeal involvement.3 CNS actinomycosis presenting as an intracranial mass is exceedingly uncommon, as described in case reports and series.1, 2, 6, 13–15 Predisposing factors were only identified in some cases, and the temporal and frontal lobes were the regions of the brain most commonly affected.9 Most of the patients presented with nonspecific features, overlapping with other intracranial masses or infections.8, 16 In our case, a 29-year-old male who presented with an insidious onset and nonspecific symptoms, poor hygiene and multiple dental caries were identified as risk factors. Hematogenous spread from remote infections was the most common source, followed by direct extension from adjacent areas.2, 4 Focal subcutaneous and intracranial actinomycetoma following trauma to the head has also been reported.17 These reports showed a localized form of CNS actinomycosis with minimal or no involvement of the scalp and skull. To the best of our knowledge, primary invasive cranial actinomycosis with simultaneous and diffuse involvement of the scalp, skull, and brain with a dura-based mass simulating a tumor has not been reported in the literature.

Head imaging modalities, including CT and MRI, can help to characterize the lesion but are not diagnostic.2, 8, 10, 12 Our patient had multiple scalp abscesses, bilateral diffuse reactive sclerosis of the skull, and a dura-based moderately post–contrast-enhancing mass with patchy meningeal involvements. This made it very difficult to consider the diagnosis of actinomycosis preoperatively. There are many neoplastic, inflammatory, or infectious causes that result in similar clinical and imaging findings. Surgical intervention involves microsurgical excision of the granuloma (actinomycetoma), abscess drainage, and debridement of the involved part.3, 11 Our patient had extensive and diffuse involvement, making it extremely difficult not only to diagnose preoperatively but also to totally excise the involved parts. The diagnosis of actinomycosis was confirmed by histopathological results.

Histopathological examination of the involved tissue remains the cornerstone in the definitive diagnosis of actinomycosis.3, 8, 10, 12, 13 Microscopically, actinomycosis appears as a scattered cluster of sulfur granules, which are composed of colonies of Actinomyces with branching filaments. The periphery of the granule contains eosinophilia in a club-shaped configuration (the Splendore-Hoeppli phenomenon) surrounded by fibrosis and many inflammatory infiltrates, suggesting its chronic and granulomatous process.8, 12, 18 Our patient typically shares almost all of these histological features. Actinomyces could be isolated from the culture of the involved tissue (biopsy or pus), but the sensitivity is very low (53.4%), as it is slow growing, has a microaerophilic or anaerobic character, and may be inhibited by previous antibiotics or other bacteria.1, 3 However, yield from a culture might be improved with strict anaerobic processing and prolonged incubation of at least 10 days.1

There are no standardized guidelines describing the optimal choice and duration of antibiotics, particularly for cranial actinomycosis with CNS involvement.1, 3, 4 The management approach varies based on the experience of treating clinicians and the availability of antibiotics. Generally, actinomyces are very sensitive to antibiotics such as penicillin, ampicillin, and amoxicillin.1, 7, 10, 12 Other alternative antibiotics include tetracycline, erythromycin, ceftriaxone, and clindamycin.1, 3, 4 A combination of antibiotics is warranted in the presence of polymicrobial infections.1 CNS actinomycosis requires high-dose and prolonged intravenous therapy.2, 3 Broad-spectrum antibiotics like piperacillin-tazobactam, imipenem, and meropenem are found to be active but should be limited in cases of recurrence or treatment failure to avoid resistance to bacteria.1 The duration of antibiotics varies from 4 weeks to 1 year, depending on the extent of the infection and degree of excision and debridement.2–4 Our patient was administered an intravenous high dose of ceftriaxone for 4 weeks, followed by oral amoxicillin for 12 more weeks.

CNS involvement is a slow but severe form of infection with a mortality rate of 28% and a morbidity rate of 54%, as reported by Plumb in 1987.19 A recent review of the literature showed an improved outcome with an overall patient fatality rate of 11% and a residual neurological deficit rate of 22%.3 CNS actinomycosis is a curable disease, particularly if identified early and properly treated with prolonged antibiotics.2, 3 When indicated, safe and aggressive microsurgical intervention of CNS actinomycotic granuloma or abscess promotes early relief from the mass effect, facilitates antibiotic penetration, and shortens the duration of antibiotics, thereby minimizing recurrences and improving functional recovery.2–4, 19

Lessons

An invasive and diffuse cranial actinomycosis with a dura-based actinomycotic granuloma is a rare clinical presentation that causes a diagnostic challenge due to its nonspecific clinical manifestations. Imaging is helpful in localizing and characterizing the lesion; however, histopathological study of the involved tissue or pus remains the gold standard for diagnosing actinomycosis. A high index of suspicion is also needed in patients with predisposing factors to promote an early diagnosis and the initiation of appropriate treatments to improve overall functional recovery and limit residual neurological deficits.

Acknowledgments

We express our gratitude to the patient for consenting to the publication of this case.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Gebrewahd, Laeke, Wondimagegnewu, Shiferaw, Tefera, Aliye, Mekuria, Mendere, Abelti. Acquisition of data: Gebrewahd, Laeke, Shiferaw, Aliye, Robele, Mendere, Abelti. Analysis and interpretation of data: Gebrewahd, Wondimagegnewu, Aliye, Berga, Mendere. Drafting the article: Gebrewahd, Shiferaw, Aliye, Mekuria, Mendere, Abelti. Critically revising the article: Gebrewahd, Laeke, Wondimagegnewu, Shiferaw, Tefera, Aliye, Mekuria, Mendere. Reviewed submitted version of manuscript: Gebrewahd, Shiferaw, Tefera, Aliye, Robele, Mekuria, Mendere. Approved the final version of the manuscript on behalf of all authors: Gebrewahd. Statistical analysis: Gebrewahd, Aliye. Administrative/technical/material support: Gebrewahd, Aliye. Study supervision: Gebrewahd, Wondimagegnewu, Aliye, Mendere, Abelti.

Correspondence

Dejen T. Gebrewahd: Addis Ababa University, Addis Ababa, Ethiopia. dejentek2005@gmail.com.
==== Refs
References

1. Valour F Sénéchal A Dupieux C , et al. Actinomycosis: etiology, clinical features, diagnosis, treatment, and management. Infect Drug Resist. 2014;7 :183-197.25045274
2. Mishra A Prabhuraj AR Bhat D Nandeesh BN Mhatre R . Intracranial actinomycosis manifesting as a parenchymal mass lesion: a case report and review of literature. World Neurosurg. 2019;122 :190-194.30391617
3. Meena DS Kumar D Sharma M , et al. The epidemiology, clinical presentation and treatment outcomes in CNS actinomycosis: a systematic review of reported cases. Orphanet J Rare Dis. 2023;18 (1 ):133.37269006
4. Akhaddar A Elouennass M Baallal H Boucetta M . Focal intracranial infections due to Actinomyces species in immunocompetent patients: diagnostic and therapeutic challenges. World Neurosurg. 2010;74 (2-3 ):346-350.21492568
5. Sogoba Y Dembele JP Sogoba B , et al. A case report of an invasive scalp actinomycosis. Case Rep Clin Med. 2021;10 (2 ):34-38.
6. Mishinov SV Karchalova AM Stupak VV Serpeninova NN . Cerebral actinomycotic granuloma mimicking malignant brain tumor. Article in English, Russian. Zh Vopr Neirokhir Im N N Burdenko. 2015;79 (5 ):63-67.26528614
7. Mohindra S Savardekar A Rane S . Intracranial actinomycosis: varied clinical and radiologic presentations in two cases. Neurol India. 2012;60 (3 ):325-327.22824696
8. Ravindra N Sadashiva N Mahadevan A Bhat DI Saini J . Central nervous system actinomycosis–a clinicoradiologic and histopathologic analysis. World Neurosurg. 2018;116 :e362-e370.29751182
9. McCann A Alvi SA Newman J , et al. Atypical form of cervicofacial actinomycosis involving the skull base and temporal bone. Ann Otol Rhinol Laryngol. 2019;128 (2 ):152-156.30371104
10. Ham HY Jung S Jung TY Heo SH . Cerebral actinomycosis: unusual clinical and radiological findings of an abscess. J Korean Neurosurg Soc. 2011;50 (2 ):147-150.22053238
11. Jeong YJ Suh HW Shim HS . Cervicofacial primary cutaneous actinomycosis: surgical treatment for complete remission of the disease. J Craniofac Surg. 2017;28 (3 ):e269-e271.28468217
12. Mohamad AR Koleri J Hussain HMS Al Soub H Al Maslamani M . Recurrent skull vault actinomycosis: a case report and review of literature. IDCases. 2021;25 :e01215.34277352
13. Tena-Suck ML Calderón Garcidueñas AL , Alcocer J, et al. Meningeal actinomyces mimicking meningioma, case report. Int Clinc Med Case Rep Jour. 2022;1 (5 ):1-7.
14. Manson G Rush WE Sieracki JC Truant JP . Actinomycosis-cerebral infection presenting as a brain tumor. Henry Ford Hosp Med Bull. 1956;4 (4 ):217-223.13384916
15. Chopra S Christie M Felimban H . Intracranial actinomycosis mimicking meningioma. Ann Saudi Med. 1995;15 (5 ):515-518.17590653
16. King AD Chan YL Wong KS Sung JJ Fung K Poon WS . Cranial actinomycosis. Singapore Med J. 1998;39 (10 ):465 467.9885710
17. Verma SB Nayak S Pasale RK Kittner T Wollina U . Late complication after tropic storm accident: subcutaneous and intracranial actinomycetoma. Int Wound J. 2008;5 (5 ):655-659.18808430
18. Oukessou Y Ait Elkerdoudi M Abada RL Mahtar M . Complicated actinomycosis of the temporal bone: a historical case report. Eur Ann Otorhinolaryngol Head Neck Dis. 2015;132 (4 ):227-229.25825360
19. Plumb A . Review articles. Soc Work Educ. 2002;21 (1 ):117-123.
