A comparison of the two cases is shown in Table 1. Both patients were equally distressed on arrival, but the clinical course was more complicated in case 1 than in case 2. The diagnoses of both cases were conventional and symptomatic, involving vomiting, pain in the lower thorax, and mediastinal emphysema .
Esophagography, upright chest radiography, and chest CT are useful for accurately diagnosing Boerhaave syndrome [5,6]. In cases similar to case 1, in which patients present with major hydropneumothorax or pneumomediastinum, chest radiography is more appropriate. If such presentations are minor, as in case 2, CT is preferred, owing to recent improvements in imaging quality. In case 2, conservative treatment revealed that if inflammation due to the rupture is localized in the mediastinum, non-operative choices might be successful . Radiological modalities, however, are not useful for the diagnosis of Mallory–Weiss syndrome. In cases where Boerhaave syndrome is unlikely, endoscopy is recommended for the diagnosis and concurrent treatment, as the source of bleeding in Mallory–Weiss syndrome is difficult to detect even with contrast-enhanced imaging studies.
Boerhaave syndrome occurs owing to the lack of coordination between the upper and lower esophageal sphincters, resulting in a transmural tear of the distal esophageal wall due to an increased intragastric pressure transmitted to the esophagus during vomiting . In both presented cases, the left wall of the distal third of the esophagus was torn. This is a distinctly common localization due to the thin muscular layer, nerve and vascular entry points, and lack of support for the surrounding connective tissue .
Several reports have described diagnostic errors in which esophageal rupture was diagnosed as Mallory–Weiss syndrome [8-10]. Commonly, massive hematemesis with less pain indicates Mallory–Weiss syndrome, while minimal hematemesis with more pain indicates Boerhaave syndrome, despite both disorders presenting with an onset of vomiting after heavy drinking. Hematemesis was observed in case 2, but the endoscopic findings showed a scar only on the esophagus, not on the stomach; moreover Mallory–Weiss lesions were not observed at all (Fig. 5).
The etiologies of both Boerhaave and Mallory–Weiss syndromes are similar, both result from abnormally elevated intraluminal cardio-esophageal pressure during vomiting. Prior studies have mentioned the relationship between the two syndromes [11-17], with some even identifying Boerhaave syndrome as an extension of Mallory–Weiss syndrome [12-17]. However, this may be disputed for two reasons: the differences in the common sites (left distal esophagus vs. gastric cardia) and the scarcity of reported transitional cases. Our review of accessible transitional cases [14-17]—except for one case  that might have a true transitional lesion—showed that those cases [14-16] not only had several lacerations that extended into the submucosa of the gastric cardia but also a separate single laceration through all layers of the distal esophagus. Thus, the two syndromes are distinct, and it is worth considering that many transitional cases are situations in which both syndromes occurred independently in the same individual. Regarding pathophysiology, Mallory–Weiss lacerations are caused by repeated retching and primarily involve the part of the gastric cardia that includes the EGJ. Boerhaave’s lacerations, on the other hand, may occur all at once in the weakest part of the esophageal wall, as the muscular layer initially tears before the mucosal layer when an explosive force is applied .
In summary, we report two cases of Boerhaave syndrome with different severities. Severity may vary greatly among patients with this disorder. Plain CT can quickly and easily detect any severity of the syndrome. Further, it can differentiate Boerhaave from Mallory–Weiss syndrome; thus, it is recommended as a preliminary test, if feasible. Although the initial cause of Boerhaave syndrome is the same as that of Mallory–Weiss syndrome, the nature of the two syndromes is distinctive and correct diagnosis is essential for positive patient outcomes.