Lacrimal sac tumors are rare with epithelial tumors being the most common type. Melanoma of the lacrimal sac is an exceptional finding. Few cases have been reported so far in the literature. We report the case of a sixth year old male, with no pathological background, who was referred to the hospital for chronic dacryocystitis resistant to treatment. Computed tomography dacryocystography and magnetic resonance imaging were performed, in favor of a large mass of the lacrimal sac and lacrimal canal suggestive of melanoma. Biopsy confirmed the diagnosis. PET-CT was positive and showed abnormal activity in the lung, liver and bones, in favor of metastasis.

OBJECTIVE: To observe the imaging features of color Doppler ultrasound (CDU) and computed tomography (CT) or computed tomography dacryocystography (CT-DCG) in different types of lacrimal sac space-occupying lesions (SOLs).
METHODS: This retrospective case series study included 21 patients with lacrimal sac SOLs who underwent lacrimal sac surgery between January 2018 and March 2022. The imaging features of CDU and CT or CT-DCG in these patients were extracted from the examination cloud system. The images were observed and analyzed.
RESULTS: The detection rate of lacrimal SOLs between CDU (21/21, 100%) and CT or CT-DCG (20/21, 95.2%) had no statistically significant difference (P=1.0). CDU could detect the blood flow signals in all SOLs except mucocele and mucopeptide concretion. Among them, polyps had characteristic imaging changes on CDU and CT-DCG. The mucoceles and mucopeptide concretions had characteristic imaging changes on CDU, which could provide more information for differential diagnosis.
CONCLUSIONS: The morphology and internal blood flow signals of lacrimal sac SOLs can be observed using CDU. CT or CT-DCG has advantages in observing structural damage around the lacrimal sac mass. Therefore, CDU may be used as a routine examination to exclude lacrimal sac SOLs before dacryocystorhinostomy in the absence of preoperative CT or CT-DCG.

BACKGROUND: Our study aims to compare non-invasive imaging such as topical computed tomography dacryocystography (CTD) and topical magnetic resonance dacryocystography (MRD) in patients with epiphora.
OBJECTIVE: To evaluate the practicability of topical contrast media during helical CTD and topical saline during MRD to reveal obstruction in the nasolacrimal drainage system (NLDS).
METHODS: Twenty participants with nasolacrimal duct obstruction were observed for two years. Ten participants underwent CTD and the other 10 participants underwent MRD. Images were analyzed by two radiologists. Participants were also asked about the level of discomfort of the contrast material versus the saline solution.
RESULTS: The NLDS was seen on both CTD and MRD. Very good agreement between the two observers (κ value > 0.81) was seen according to the κ statistics. CTD multiplanar and 3D images allowed for precise diagnosis of the point of obstruction whereas, the MRD did not require any contrast material and showed the point of obstruction. Saline was more comfortable for the patients than topical contrast (P < 0.05).
CONCLUSIONS: Topical CTD and MRD are non-invasive techniques that can visualize the degree and level of obstruction in the NLDS than conventional invasive cannulation dacryocystography. CTD is useful in visualizing the point of obstruction and smaller drainage structures. However, it is a source of ionizing radiation to the lens. The benefit of MRD is that it requires no contrast or radiation; however, it is poor in depicting the bone anatomy and smaller drainage structures. Finally, saline was better tolerated by patients than topical contrast.