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See also: Laryngeal Surgery (Benign Disease) Protocols

Similar lesion in salivary gland: Oncocytoma of the Parotid Gland (Oxyphilic Adenoma; Mitochondrioma)

Note: last updated before 2013

GENERAL CONSIDERATIONS

1. Definitions
   1. Oncocyte: An epithelial cell that has undergone metaplastic changes with characteristic eosiniophillic and granular cytoplasm secondary to increased mitochondrial content.
   2. Oncocytic cystadenomas represent cystic dilatation of salivary ducts or acinar cells.
2. Epidemiology
   1. Female predominance and usually occur in 7^th to 8^th decade of life. Potential association with Warthin’s tumors of the parotid gland and most patients are found to be smokers.
3. Etiology
   1. A point of current investigation. Hypotheses include:
      1. Mitochondrial proliferation as compensation for loss of mitochondrial enzymes with age.
      2. HAART anti-retroviral therapy may alter mitochondrial DNA replication.
4. Histopathologic Diagnosis
   1. Oncocytic cystadenomas arising from minor salivary glands may be cuboidal or columnar with characteristic increased eosinophilic granular cytoplasm with small nuclei. Those arising from major salivary glands form long, tapered and cuboidal cells with similar eosinophilic changes. 
   2. These both represent hyperplasia and metaplasia of ductal cells rather than a dysplastic process and therefore not believed to be pre-malignant.
5. Histological Subtypes
   1. Cystic, papillocystic, or microcystic histologic subtypes. These are all benign and should not be confused with solid, non-cystic malignant oncocytic tumors. However, the existence of such tumors specifically in the larynx of humans is debated. 
   2. Recurrent (i.e. multifocal oncocytic cystadenomas with incomplete initial resection) may need to be differentiated from laryngeal neuroendocrine carcinoma.

EVALUATION

1. Presenting symptoms of laryngeal oncocytic cystadenomas
   1. Most commonly asymptomatic and found incidentally on endoscopic exam
   2. Symptoms include: hoarseness, stridor, or dyspnea. One case report of complete airway obstruction
2. Clinical evaluation:
   1. Majority appear on vestibular folds due to high concentration of minor seromucinous salivary glands.
      1. Supraglottic: 74%
      2. Glottic: 22%
      3. Subglottic: 4%
   2. On examination, the gross appearance is often indistinguishable from simple laryngeal cysts or polyps. The mucosa is smooth and lesions are cystic in appearance and usually smaller than 1cm.
   3. On CT, appear as well-defined, iso- or slightly hyper-dense submucosal lesions

MANAGEMENT

1. Treatment
   1. Excision during complete endoscopy is the treatment of choice.
      1. Excision should be made to prevent recurrence yet allow for ideal voice outcomes.
   2. Complete biopsy samples should be taken for adequate architectural histological analysis in order to rule out malignant lesions. 
   3. Report of laser treatment with lower recurrence rates. However, recurrence in the setting of laryngeal oncocytic cystadenoma often represents multifocal disease with incomplete resection rather than true recurrent disease.
2. Follow up 
   1. Intermittent endoscopic follow up will help identify recurrence/multi-focal disease and need for future re-excision.

REFERENCES

Oliveira CA, Roth JA, Adams GL.  Oncocytic lesions of the larynx.  The Laryngoscope.  1977; 87:1718-25

Salerno G, Mignogna C, Cavaliere M, et al.  Oncocycic cyst of the larynx: an unusual occurrence.  Acta Otorhinolaryngol Ital.  2007; 27(4):212-15

Tanweer F, Farhan W, Watson M.  Treatment of oncocytic lesions of the larynx.  Otolaryngology – Head and Neck Surgery.  2007; (137):s173-174

Travis B, Palacios E, McCarty CL.  An uncommon case of laryngeal oncocytoma.  ENT – Ear, Nose & Throat Jounral.  2011; 90(5):208-10