Hi Sunflower,
Your letter is fine, with some subtle exceptions. But just be careful because "major" and "common" are often very similar.
As I demonstrated, sometimes you can use the words interchangably.
From my quick and uneducated reading of the following URL I tend to agree that "common" is more appropriate than major.
I hope this helps you.
MountainHiker
Dear Dr. ______
The [phrase] “lymphangioma is the major cause of macroglossia” [in the article "blah" ] was confusing and did not depict the author's [authors' (if plural)] [true intent because of a] poor translation into English. In the edited manuscript, the term “major” has been replaced with “common”, which is more appropriate. References have been supplied to the statement “lymphangioma is a common cause of macroglossia in children”.
I look forward to hearing from you.
http://www.emedicine.com/ent/topic746.htm:
True macroglossia can be subdivided into 2 main subcategories, congenital causes and acquired causes.
* Congenital causes
o Idiopathic muscle hypertrophy
o Gland hyperplasia
o Hemangioma
o Lymphangioma
o Down syndrome
o Beckwith-Wiedemann syndrome
o Behmel syndrome
o Lingual thyroid
o Gargoylism
o Transient neonatal diabetes mellitus
o Trisomy 22
o Laband syndrome
o Lethal dwarfism of Blomstrand
o Mucopolysaccharidoses
o Skeletal dysplasia of Urbach
o Tollner syndrome
o Autosomal dominant inheritance
o Microcephaly and hamartoma of Wiedemann
o Ganglioside storage disease type I
* Acquired causes (Categories have been assigned to simplify the list, but there can be overlap of a particular etiology into more than one of these categories.)
o Metabolic/endocrine
+ Hypothyroidism
+ Cretinism
+ Diabetes
o Inflammatory/infectious
+ Syphilis
+ Amebic dysentery
+ Ludwig angina
+ Pneumonia
+ Pemphigus vulgaris
+ Rheumatic fever
+ Small pox
+ Typhoid
+ Tuberculosis
+ Actinomycosis
+ Giant cell arteritis
+ Candidiasis
+ Scurvy
+ Pellagra
o Systemic/medical conditions
+ Uremia
+ Myxedema
+ Hypertrophy
+ Acromegaly
+ Neurofibromatosis
+ Iatrogenic macroglossia
o Traumatic
+ Surgery
+ Hemorrhage
+ Direct trauma (eg, biting)
+ Intubation injury
+ Radiation therapy
o Neoplastic
+ Lingual thyroid
+ Lymphangioma
+ Hemangioma
+ Carcinoma
+ Plasmacytoma
o Infiltrative
+ Amyloidosis
+ Sarcoidosis