Posterior Mediastinal Paravertebral Müllerian Cyst (Cyst of Hattori): Literature Review

Abstract

Mediastinal cysts are typically of bronchogenic, thymic or neurenteric origin, but may also represent oesophageal duplication. Posterior paravertebral mediastinal Müllerian cysts of undetermined pathogenesis are very rare occurrences. The first case of a ciliated cyst arising in the mediastinum, of probable Müllerian origin, was reported by Hattori in 2005, which gave rise to the name cyst of Hatorri (COH) The number of reported cases in literature of a similar nature have since then increased significantly. One of the main concerns about this pathology is the possibility of malignant transformation of the Müllerian tissue. Over the course of this paper we will discuss the pathogenesis, immunohistochemistry and its role in differential diagnosis as well as optimal treatment of such cysts.

Cyst of Hattori: A Rare Cyst in the Posterior Mediastinum

“…1 Our patient was unique in the globus sensation and choking sensation that she reported. However, it is important to note that she was initially asymptomatic, consistent with approximately 55% of reported cases 3 and that her symptoms were significantly improved by an esophageal dilation performed at an outside facility, suggesting that her complaints were unrelated to the cyst.…”

“…Ever since their discovery by Hattori in 2005, over 40 examples of posterior mediastinal Mullerian cysts have been reported. 3 So far as we know, this is the second report of a Hattori cyst resected by robot-assisted thoracoscopic surgery in the English literature, following Chao's 2018 case report. 7 Apart from Hattori's initial patient – an 18 year old woman 2 and Skancke's 35 year old patient 8 – our patient is consistent with the age and gender of other reported patients; a woman between 40 and 60 years of age.…”

“…Additionally, our patient presented with an elevated body mass index (BMI) and the possibility of a history of a gynecological abnormality from the previous hysterectomy, which is also consistent with previous case reports. 3,9 Simmon's 2013 report was the first to demonstrate PAX8 and WT1, both markers of Mullerian differentiation, in the cysts of Hattori, 10 a finding supported by multiple papers since. 7,8 As in these cases, our sample was positive for both PAX8 and WT1, strongly supporting a cyst of Hattori.…”

“…Additionally, our patient presented with an elevated body mass index (BMI) and the possibility of a history of a gynecological abnormality from the previous hysterectomy, which is also consistent with previous case reports. 3,9…”

“…1 These cysts, known as cysts of Hattori after their discovery by Hideo Hattori in 2005, can be distinguished by a lining of ciliated non-stratified cuboidal and columnar epithelium positive for both estrogen and progesterone receptors. 2 Due to the rarity of these cysts – to date, approximately 40 have been identified in the literature, 3 their origin remains unclear. In most cases, they are initially misdiagnosed as a bronchogenic, neurogenic, or neuroenteric cyst, before pathology can confirm that they are of Mullerian origin.…”