Achalasia is a primary esophageal motility disorder, which manifests itself through dysphagia to liquids and solid foods. Support for a diagnosis of achalasia can be obtained by endoscopic and radiological studies, but the mainstay of the diagnostic process consists of the manometric findings. Classically, three characteristic manometric features are present in achalasia: an elevated resting lower esophageal sphincter pressure, incomplete lower esophageal sphincter relaxation, and esophageal aperistalsis [
4]. Pseudoachalasia is characterized by achalasia-like symptoms caused by secondary etiologies. Clinical, radiological, and endoscopic findings closely resemble those of achalasia, but the treatment and associated prognosis are markedly different [
5]. Hence, correct discrimination between achalasia and pseudoachalasia is important, but it is frequently complicated by the absence of specific pseudoachalasia-specific symptoms or findings and the relative rarity of pseudoachalasia. In our patient, the overall clinical, endoscopic, and radiographic findings clearly favored achalasia, especially in view of the concordant manometric classic type II achalasia pattern observed. Why the pseudoachalasia presented with this manometry remains unresolved and highlights the challenges that could be encountered when trying to make the correct diagnosis in this context. However, the observation of the lower esophageal leiomyoma made a differential diagnosis of pseudoachalasia more likely. Leiomyoma is the main type of submucosal tumor (SMTs) in the esophagus and its presence may manifests itself in dysphagia [
6]. Interestingly, achalasia misdiagnosis in SMT-mediated dysphagia has been reported multiple times in previous studies [
7,
8] and thus this alternate diagnosis should always be in the differential diagnosis even when achalasia-concordant manometry is available. Moreover, clues to distinguish achalasia from pseudoachalasia can result from endoscopic ultrasound (EUS) [
9], thus this case supports the use of EUS investigation upon this type of clinical presentation. The present case management did not involve EUS before endoscopic surgery, but in retrospect this would have been desirable.
POEM is a novel endoscopic technique for the treatment of achalasia. Since Inoue et al. [
10] reported its safety and effectiveness in humans, many groups have reported similar results with minimal complications [
11,
12]. Based on POEM, Xu et al. [
13] developed a new endoscopic technique named STER for treating SMTS originating from the muscularis propria in the esophagus. It has already been reported that STER is also safe, effective, and feasible with respect to SMTs at the esophagogastric junction, combining the possibility for accurate histopathologic evaluation of the lesion with its curative treatment [
14]. The successful application of STER in the present study supports this notion. As both POEM and STER are in essence endoscopic tunneling techniques, they share most of technical procedures. For the present case, this was a fortunate coincidence since POEM was initiated while STER was needed to be performed, and thus secondary surgery could be avoided. It is clear, however, from this case and the body of available literature that STER might be an option for the treatment of pseudoachalasia caused by leiomyoma of EGJ.