The usual location of Glomus jugulare tumour is:
**Core Concept**
Glomus jugulare tumors are a type of paraganglioma that arise from the temporal bone, specifically in the jugular bulb. They are a rare, benign neoplasm that can cause significant morbidity due to their potential to invade surrounding structures and lead to complications.
**Why the Correct Answer is Right**
Glomus jugulare tumors typically present in the middle ear, specifically in the jugular bulb, which is a venous structure located within the temporal bone. They originate from the paraganglia cells, which are part of the chemoreceptor system. The jugular bulb is a common location for these tumors due to the presence of paraganglia cells in this area. The tumors can grow and invade surrounding structures, including the carotid artery, jugular vein, and cranial nerves.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it is not a typical location for glomus jugulare tumors. Glomus tympanicum tumors, another type of paraganglioma, are more commonly found in the middle ear.
**Option B:** This option is incorrect as it is not a correct anatomical location for glomus jugulare tumors. The internal auditory canal is a different structure that is involved in the transmission of sound signals.
**Option C:** This option is incorrect as it is not a typical location for glomus jugulare tumors. The petrous apex is a different part of the temporal bone that is not commonly involved in glomus jugulare tumors.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that glomus jugulare tumors can cause symptoms such as hearing loss, tinnitus, and vertigo due to their location in the middle ear and their potential to invade surrounding structures.
**Correct Answer:** C.