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Introduction A constant infusion of local anesthetics through pain pumps has been shown to cause chondrolysis. However, there is no general consensus regarding the safety of a single intra-articular injection of local anesthetics. In this experimental study, we examined the rat cartilage for possible histological effects after a single intra-articular administration of lidocaine or ropivacaine. Material and methods Thirty-two male Sprague-Dawley rats, weighing 250-300 grams, were divided into two groups of 16 each. We injected 0.1 ml of either lidocaine 2% (20 mg/ml) or ropivacaine 0.75% (7.5 mg/ml) into the left knee of the rats. The right knee in both groups was used as a control, and an equal amount of normal saline was injected. Each group was further divided into subgroups of four, which were euthanized after one, seven, 21, and 60 days after the initial injection. Knees were excised and prepared for histopathological analysis. A modified version of the Mankin score was used for cartilage damage evaluation. Results No difference regarding cartilage damage was detected after the examination under light microscopy between lidocaine, ropivacaine, and placebo in all specimens. Time elapsed since the initial injection did not affect the results at any time point. Conclusion A single intra-articular injection of local anesthetic did not induce any histological changes in the rat cartilage. Further research is needed to demonstrate the safety of humans.
RESUMO
Invasive micropapillary carcinoma (IMPC) is a rare, distinct histological subtype of breast carcinoma. While micropapillary histological architecture is found in up to 2-8% of all breast cancers, pure micropapillary carcinoma is infrequent and comprises 0.9-2% of breast carcinomas. Invasive micropapillary carcinoma is emerging as an oncological and surgical challenge due to a plethora of characteristics that constitute this histological pattern - interestingly, both elusive and aggressive. We present the case of a woman presenting with IMPC, who was primarily treated with tumour and lymph node marking, followed by primary systemic therapy (PST), and consequent oncoplastic surgery with sentinel lymph node biopsy. Our case report outlines the importance of awareness of histological subtypes in breast cancer by focusing on a case report of IMPC. The breast surgeon must be aware of the lymphotropic behaviour of this subtype and the high prevalence of lymph node involvement in such patients, and therefore focus on rigorous axillary assessment. One must not forget that, despite having a more aggressive biological profile, IMPC has demonstrated no difference in survival when compared to other histological subtypes, and treatment should conform to international guidelines with an emphasis on nodal staging.
RESUMO
Invasive micropapillary carcinoma (IMPC) of the breast is an infrequent type of breast cancer often discussed for its potency for lymphovascular invasion and difficulty in accurate imaging estimation. Micropapillary carcinomas are noted to be present as larger tumors, of higher histological grade and a notably higher percentage of disease-positive lymph nodes. Hormonal and HER-2 positivity in IMPC is also commoner when compared to other NST carcinomas. IMPC occurs either as a pure form or more often as a component of mixed Non-Specific Type (NST) carcinoma. The latest data suggest that despite having comparable survival rates to other histological subtypes of breast carcinoma, effective surgical treatment often requires extended surgical margins and vigilant preoperative axillary staging due to an increased incidence of lymph node invasion, and locoregional recurrence. Moreover, the presence of micropapillary in situ components within tumors also seems to alter tumor aggression and influence the nodal disease stage. In this review, we present an overview of the current literature of micropapillary carcinoma of the breast from biology to prognosis, focusing on biological differences and treatment.
