Primary malignant melanoma of the nasolacrimal duct is a rare and aggressive mucosal neoplasm. Its diagnosis is frequently delayed because early symptoms often mimic benign inflammatory conditions like chronic dacryocystitis. While hemolacria is considered a hallmark sign, it is not universally present. We present a case of a 78-year-old woman with a 1-year history of persistent epiphora and discharge from the left eye, without hemolacria. Initial lacrimal irrigation suggested obstruction. Computed tomography (CT) revealed a soft tissue lesion with widening of the lacrimal bony canal but without gross destruction. An incisional biopsy confirmed malignant melanoma. The patient underwent wide surgical resection, including medial maxillectomy, followed by adjuvant intensity-modulated radiotherapy (50 Gy). The tumor was BRAF wild-type. At 24 months post-treatment, the patient remains disease-free with no evidence of recurrence or metastasis. This case highlights that the absence of hemolacria should not preclude the suspicion of malignancy in refractory lacrimal obstruction. Early cross-sectional imaging and biopsy are essential for accurate diagnosis. Furthermore, this case suggests that a multimodal approach combining wide surgical excision and adjuvant radiotherapy may contribute to durable local control in selected patients.

Background/Objectives: Ceftolozane/tazobactam (C/T) and ceftazidime/avibactam (CZA) are critical therapeutic options for multidrug-resistant Gram-negative infections; however, their comparative pharmacodynamics against carbapenem-resistant Pseudomonas aeruginosa (CRPA) remain incompletely defined. This study aimed to compare the bactericidal activity of C/T and CZA administered by intermittent infusion (II) or continuous infusion (CI) using a hollow fiber infection model (HFIM) against a clinical isolate of CRPA. Methods: Clinically relevant concentration–time profiles for C/T and CZA based on prescribing information were simulated in the HFIM. The standard P. aeruginosa strain ATCC 27853 and a GES-producing clinical CRPA isolate were utilized. The primary endpoint was bactericidal activity (≥3 log₁₀ CFU/mL reduction from baseline), while secondary endpoints included regrowth prevention and resistance development based on population analysis profiles (PAPs). Results: Against the standard strain, both agents achieved rapid killing without regrowth. However, for the GES-producing clinical isolate, C/T failed to achieve bactericidal activity. In contrast, CZA demonstrated sustained bacterial killing activity with the most pronounced early-phase bactericidal activity with CI of CZA (−4.25 log₁₀ CFU/mL at 24 h). The bactericidal activity was persistent over 7 days without bacterial regrowth after treatment discontinuation. Conversely, bacterial regrowth occurred with II of CZA after drug withdrawal. PAPs showed the lack of resistance development against CZA, whereas resistance to C/T developed within 48 h after initiating therapy. Conclusions: In this HFIM study, CI of CZA demonstrated the most sustained suppression of bacterial growth and prevented resistance emergence against the tested clinical isolate of CRPA producing GES β-lactamases. Future clinical studies are warranted to assess the effectiveness of the CI regimen.