Levator glandulae thyroideae muscle

Last revised by Daniel J Bell on 27 Aug 2021

The levator glandulae thyroideae muscle (a.k.a. musculus levator glandulae thyroideae or levator glandulae thyroideae of Soemmerring) is an anatomic variant, consisting of a band of fibrous/fibromuscular tissue, connecting the pyramidal lobe of the thyroid to the hyoid bone. When muscle fibers are present it is an accessory muscle.

It is most commonly found on the left side of the neck 1,2. A true midline structure is very rare 1. Although the pyramidal lobe is usually present, it is neither a constant, nor necessary, finding in those with this variant fibromuscular structure 1.

In the 1960s, in a large Japanese study of 210 cadavers with a levator glandulae thyroideae, Mori classified them into five main types 4:

  1. hyopyramidalis muscle
    • hyoid bone to pyramidal lobe
  2. thyreopyramidalis muscle
    • thyroid cartilage to pyramidal lobe
  3. thyreoglandularis muscle
    • thyroid cartilage to the thyroid capsule
  4. hyoglandularis muscle
    • hyoid bone to the thyroid capsule
  5. tracheoglandularis muscle
    • proximal trachea to the isthmus of the thyroid

The levator glandulae thyroideae muscle originates from the inferior margin of the hyoid bone most frequently. Alternately, it may be rarely found to arise from the thyroid cartilage, or even the trachea 1,4.

When present, the levator glandulae thyroideae muscle most commonly inserts into the pyramidal lobe, much less commonly, the superior isthmus of the thyroid.

  • elevates the thyroid 5

The Prussian neuroanatomist, Samuel Thomas Soemmerring (1755-1830) described this thyroid variant in a report published in 1794. Although historically, Soemmerring is remembered most strongly for his cutting-edge work on the anatomy of the cranial nerves 3,5.

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