[Bilateral absence of the quadrangular space of the axilla]

In the 1988 student course on gross anatomy dissection of cadavers at Iwate Medical University School of Medicine, two cases of the absence of the quadrangular space of the axilla were found bilaterally in a 92-year-old female who had died of heart failure. The cases were investigated anatomically. The tendons of insertion of the latissimus dorsi and the teres major muscles and the tendon of origin of the long head of the triceps brachii muscle were united, forming a conjoint tendon that attached to the infraglenoid tubercle of the scapula and the lower part of the anatomical neck of the humerus adhering to the articular capsule of the shoulder joint. The subscapularis muscle was normal except that a muscular bundle arose from the conjoint tendon and inserted to the lesser tubercle of the humerus and the crest continuing down from the tubercle. A part of the conjoint tendon was covered by the insertion of the subscapularis muscle, and there was no space between the conjoint tendon and the insertion of the subscapularis muscle. The teres major muscle was poorly developed, but the area of origin was rather wide and arose from both the dorsal and costal surfaces of the scapula. The anatomical features of the latissimus dorsi and the long head of the triceps brachii muscles were normal except for the insertion of the former and the origin of the latter. The triangular space of the axilla was found to be surrounded by the conjoint tendon, teres major muscle, and the lateral border of the scapula covered by the subscapularis and the teres minor muscles.(ABSTRACT TRUNCATED AT 250 WORDS)