RESUMO
Introduction and importance: Liposarcoma (LPS) is a common soft-tissue sarcoma predominantly diagnosed in adults, arising from malignant adipose cells. Among its various subtypes, myxoid LPS (MLPS) stands out as the second most frequent, accounting for ~30% of all LPS cases. This particular subtype typically manifests in males between the ages of 40 and 50 and is commonly found in the lower extremities. Although rare, MLPS may also occur in the head, neck, and infrequently in the back. Chest wall LPS cases are also sparsely reported. Case presentation: In this report, we present a case of MLPS in a 69-year-old male patient who presented with a complaint of firm swelling on the right posterior chest wall, which was progressively increasing in size over the past 10 years. The tumour was located in the posterior chest wall on the left side, and further diagnostic evaluation using computed tomography (CT) and MRI was conducted to identify its characteristics and extent. Clinical discussion: The use of CT scanning plays a crucial role in differentiating between various lipomatous tumour types, aiding in the identification and classification of MLPS. However, MRI emerges as a more effective technique for detecting microscopic fat compared to CT or ultrasonography, providing valuable insights for accurate diagnosis and treatment planning. Conclusion: Surgery remains the primary therapeutic approach for managing LPSs, including MLPS. Adjuvant preoperative radiation is recommended due to its significant sensitivity and potential for improved outcomes. Given the rarity of this presentation and the varied anatomical locations, a multidisciplinary approach is paramount in effectively managing such cases. Medical practitioners should collaborate closely, considering the unique challenges posed by MLPS to ensure optimal patient care and treatment outcomes.
RESUMO
In this paper, we present the performance and stability of an erbium-doped fiber laser (EDFL) based on ZnO saturable-absorber (SA) prepared using two schemes: solution method (SM) and pulsed laser deposition technique (PLDT). It was observed that EDFL with ZnO-SA prepared using SM emits at 1561.25 nm under a pump power of 230 mW. As the pump power is increased from 22.2 mW to 75.3 mW, the pulse duration decreases from 24.91 to 10.69 µs, and the pulse repetition rates increase from 11.59 to 40.91 kHz. Besides at pump power of 75.3 mW, the peak power, pulse energy, and average output power are measured as 0.327 mW, 2.86 nJ, and 0.18 mW, respectively. However, when PLDT-based SA was incorporated into the ring cavity, the emission wavelength is noticed at 1568.21 nm at a pump power of 230 mW. With the increase in pump power from 22.2 mW to 418 mW, the pulse repetition rates increase from 10.79 to 79.37 kHz and the pulse width decreases from 23.58 to 5.6 µs. Furthermore, the peak power, pulse energy, and average output power are observed to be 10.9 mW, 74 nJ, and 5.35 mW, respectively. The stability of EDFL based on SAs prepared using SM and PLDT has also been investigated. To the best of the author's knowledge, it is the first comparison of performance and long-term stability of EDFL based on two experimental techniques SM and PLDT-based SAs. These findings suggest that PLDT-based SAs provides optimum stability over a long period and enhanced the performance of fiber lasers compared to the SAs prepared using the conventional SM technique. This study paves the way for the development of ultra-stable SAs for their potential applications in pulsed laser sources and photonic devices.
