Sandbox:Sahar

• On microscopic histopathological analysis, carotid body tumor composed of:
  • The chief or paraganglionic cells composing the predominant part of the tumor and contain eosinophilic granular materials and oval or round nuclei.
  • The supporting or sustentacular cells responsible for the chemoreceptor activity of the carotid body
• The characteristic finding of this tumor is:

• Chief cells Arranged in distinctive pattern called cell balls (zellballen)
• Separated by fibrovascular stroma and surrounded by sustentacular cells
• The cytoplasm is pale and diffuse with occasional presence of the eosinophilic granules.
• The nuclei are round to spindle shape.

• The tumor is highly vascular.
• Although there is no well-accepted histologic criteria for the diagnosis of malignant tumors, worrisome histologic features include:
  • Necrosis
  • Extensive vascular or capsular invasion
  • Increased mitotic activity
  • Atypical mitotic figures

Features on Gross Pathology	Image
Characteristic findings of carotid body tumor, include: Well-circumscribed with psudocapsule The size of the tumor varies greatly and it may be as large as 10 cm The cutting surface is solid with a smooth, rubbery texture||	Contributed by Paweł Kuźniar in wikimedia.commons

Patient with carotid body tumor

History, Physical examination, and evaluation of cnotralateral side

Patients with age < 50 years Patients with multiple paraganglioma Patients with a positive family history

The rest of the patients

SDHD genetic testing

Presence of SDHD mutation

Absence of SDHD mutation

SDHC and SDHB genetic testing

Presence of SDHC/B mutation

Absence of SDHC/B mutation

All the relatives should be evaluated for the presence of paragnaglioma

whole-body 18F-dihydroxyphenylalanine (F-DOPA) positron emission tomography to assess the presence of other paragangliomas

Presence of other paraganglioma

Absence of other paraganglioma

24-hour urine catecholamines and MRI for biochemical screening

surveillance screening every 5 years