Jorge E Falco

Sentinel Lymph Node

AbstractIntroduction: Lymph node status in patients with cutaneous malignant melanoma is the most important prognostic factor. Patients with clinically positive nodes (stage III) should undergo therapeutic lymphadenectomy; however, the surgical approach to the regional disease in patients with negative clinical examination (stage I and II) is still controversial. Selective lymphadenectomy consists of the intraoperative identification of the first node in the nodal basin, the sentinel lymph node (SLN). Routine examination, serial sectioning, and immunohistochemistry may underestimate the presence of tumor cells. PCR is a molecular biology technique that may be useful for the detection of malignant melanoma nodal metastases in the SLN. Aim: The aim of this study was to use tyrosinase messenger RNA (mRNA) amplification for the detection of micrometastases in fresh frozen SLNs. Methods: 46 hematoxylin-eosin (HE)-negative sentinel node samples from 42 patients with malignant melanoma were included in this study. Formalin-fixed paraffin-embedded sections were immunostained with S-100 protein and HMB-45. A central portion of the node was submitted for PCR. This method was accomplished with a combination of reverse transcription and amplification of the tyrosinase complementary DNA and double-round PCR (nested reverse transcriptase [RT]-PCR). Results: In 1 of the 42 SLN-negative patients, immunohistochemistry stains allowed the detection of micrometastases. With molecular biology, 14 of the 42 SLN patients were positive (33%); in another 12 (29%), only the nested RT-PCR was positive. Of the 42 patients, 24 were put into 3 groups and followed for a 5-year period with 1, 7, and 16 patients, respectively, in the groups. The first group involved 1 patient who had provided 2 SLN samples that were found to be SLN-positive using both techniques, immunohistochemistry stains and nested RT-PCR (he had hepatic metastasis and died 24 months after diagnosis). The second group, with only nested RT-PCR positive SLN samples, included 7 of 12 patients who were followed and had a median survival of 37 months; 4 died of widespread metastatic disease, the other 3 patients had event-free survival, but 1 consented to undergo a therapeutic lymphadenectomy as a result of a positive test. The last group consisting of 16 of 32 patients, with complete 5-year survival, who were SLN-negative with both techniques, immunohistochemistry stains and nested RT-PCR. Fourteen of the 16 (88%) were event-free survival during the follow-up, and 2 had local relapse. Conclusion: Tyrosinase mRNA amplification may be a negative prognostic factor for the detection of micrometastases in fresh frozen SLNs using molecular biology techniques.

Sentinel node in melanoma patients: triple negativity with routine techniques and PCR as positive prognostic factor for survival.

Lymph node mapping and sentinel lymph node biopsy are currently used to stage patients with cutaneous malignant melanoma. Immunohistochemical stains contribute to the detection of micrometastases; however, molecular biology techniques are associated with better diagnostic sensitivity. Sixty sentinel lymph nodes were included in this study. The primary lesions were malignant melanoma stage I or II, with a follow-up of longer than 2 years. Sentinel lymph nodes were studied with hematoxylin–eosin, immunohistochemistry for S-100 and HMB-45, and molecular biology techniques (reverse transcription (RT)-PCR) for the detection of tyrosinase messenger RNA. In 15 of 60 cases (25%), tyrosinase was detected by RT-PCR; three of these cases were also positive by immunohistochemistry. The population was divided into three groups: (i) hematoxylin–eosin−/immunohistochemistry+/molecular biology techniques+ (3 cases); (ii) hematoxylin–eosin−/immunohistochemistry−/molecular biology techniques+ (12 cases); (iii) hematoxylin–eosin−/immunohistochemistry−/molecular biology techniques− (45 cases). Correlation of the groups with overall survival showed the following: (i) 2 of 3 patients died (67%); (ii) 5 of 12 died (42%), and (iii) all 45 patients are alive, with no lymphadenectomy and a median follow-up of 84 months. The inclusion of molecular biology techniques appears to be of great value for the detection of sentinel lymph node micrometastases in patients with cutaneous malignant melanoma. In our series, those patients who showed negativity with all the three methods had a null recurrence rate. Therefore, this triple negativity could be a positive prognostic factor for overall survival. Our findings suggest the possibility of molecular oncological staging, which would allow the selection of patients with submicroscopic metastases for a complete treatment.

Sentinel lymph node: detection of micrometastases of melanoma in a molecular study.

INTRODUCTION Lymph node status in patients with cutaneous malignant melanoma is the most important prognostic factor. Patients with clinically positive nodes (stage III) should undergo therapeutic lymphadenectomy; however, the surgical approach to the regional disease in patients with negative clinical examination (stage I and II) is still controversial. Selective lymphadenectomy consists of the intraoperative identification of the first node in the nodal basin, the sentinel lymph node (SLN). Routine examination, serial sectioning, and immunohistochemistry may underestimate the presence of tumor cells. PCR is a molecular biology technique that may be useful for the detection of malignant melanoma nodal metastases in the SLN. AIM The aim of this study was to use tyrosinase messenger RNA (mRNA) amplification for the detection of micrometastases in fresh frozen SLNs. METHODS 46 hematoxylin-eosin (HE)-negative sentinel node samples from 42 patients with malignant melanoma were included in this study. Formalin-fixed paraffin-embedded sections were immunostained with S-100 protein and HMB-45. A central portion of the node was submitted for PCR. This method was accomplished with a combination of reverse transcription and amplification of the tyrosinase complementary DNA and double- round PCR (nested reverse transcriptase [RT]-PCR). RESULTS In 1 of the 42 SLN-negative patients, immunohistochemistry stains allowed the detection of micrometastases. With molecular biology, 14 of the 42 SLN patients were positive (33%); in another 12 (29%), only the nested RT-PCR was positive. Of the 42 patients, 24 were put into 3 groups and followed for a 5-year period with 1, 7, and 16 patients, respectively, in the groups. The first group involved 1 patient who had provided 2 SLN samples that were found to be SLN-positive using both techniques, immunohistochemistry stains and nested RT-PCR (he had hepatic metastasis and died 24 months after diagnosis). The second group, with only nested RT-PCR positive SLN samples, included 7 of 12 patients who were followed and had a median survival of 37 months; 4 died of widespread metastatic disease, the other 3 patients had event-free survival, but 1 consented to undergo a therapeutic lymphadenectomy as a result of a positive test. The last group consisting of 16 of 32 patients, with complete 5-year survival, who were SLN-negative with both techniques, immunohistochemistry stains and nested RT-PCR. Fourteen of the 16 (88%) were event-free survival during the follow-up, and 2 had local relapse. CONCLUSION Tyrosinase mRNA amplification may be a negative prognostic factor for the detection of micrometastases in fresh frozen SLNs using molecular biology techniques.

Cutting Edge in Thyroid Surgery: Autofluorescence of Parathyroid Glands

BACKGROUND Identification of parathyroid glands may be challenging during thyroid and parathyroid surgery. Accidental resection of the glands may increase the morbidity of the surgery. The aim of this study was to evaluate accuracy in identification of autofluorescent parathyroid glands with the use of near infrared light in real time. STUDY DESIGN Patients undergoing thyroid and parathyroid surgery between June and August 2015 were included in the study. During the procedure, the surgical field was exposed to near infrared laser light in order to analyze the intensity of the fluorescence of different tissues (parathyroid glands, thyroid glands, and background). Surgical images were recorded and analyzed. RESULTS Twenty-eight patients were included in the study. Nineteen patients were women and 9 were men. Seven patients had primary hyperparathyroidism, 4 had hyperthyroidism, 3 had goiters, and 11 had thyroid cancer. Three patients had mixed pathologies, including 2 patients with thyroid cancer and primary hyperparathyroidism and 1 patient with goiter and primary hyperparathyroidism. Identification of autofluorescent parathyroid glands was achieved in all patients with near infrared light. The mean fluorescent intensity of parathyroid glands was 40.6 (±26.5), thyroid glands 31.8 (±22.3), and background 16.6 (±15.4). Parathyroid glands demonstrated statistically higher fluorescence intensity compared with the thyroid gland and background (p < 0.0014). No postoperative hypocalcemia or other complications related to the surgery were registered. CONCLUSIONS Visualization of autofluorescent parathyroid glands with the use of near infrared light allows high rates of parathyroid gland identification and could be a safe, feasible, and noninvasive method for intraoperative identification of parathyroid glands in real time. Further clinical studies must be performed to determine the cost-effectiveness and clinical application of this method.

Increased identification of parathyroid glands using near infrared light during thyroid and parathyroid surgery

BackgroundParathyroid gland (PG) identification during thyroid and parathyroid surgery is challenging. Accidental parathyroidectomy increases the rate of postoperative hypocalcaemia. Recently, autofluorescence with near infrared light (NIRL) has been described for PG visualization. The aim of this study is to analyze the increased rate of visualization of PGs with the use of NIRL compared to white light (WL).Materials and methodsAll patients undergoing thyroid and parathyroid surgery were included in this study. PGs were identified with both NIRL and WL by experienced head and neck surgeons. The number of PGs identified with NIRL and WL were compared. The identification of PGs was correlated to age, sex, and histopathological diagnosis.ResultsSeventy-four patients were included in the study. The mean age was 48.4 (SD ±13.5) years old. Mean PG fluorescence intensity (47.60) was significantly higher compared to the thyroid gland (22.32) and background (9.27) (p < 0.0001). The mean number of PGs identified with NIRL and WL were 3.7 and 2.5 PG, respectively (p < 0.001). The difference in the number of PGs identified with NIRL and WL and fluorescence intensity was not related to age, sex, or histopathological diagnosis, with the exception of the diagnosis of thyroiditis, in which there was a significant increase in the number of PGs visualized with NIRL (p = 0.026).ConclusionThe use of NIRL for PG visualization significantly increased the number of PGs identified during thyroid and parathyroid surgery, and the differences in fluorescent intensity among PGs, thyroid glands, and background were not affected by age, sex, and histopathological diagnosis.

Past, Present, and Future of Fluorescence

It is important to define fluorescence. There are several ways to describe this term: (1) the emission of electromagnetic radiation, especially of visible light, stimulated in a substance by the absorption of incident radiation and persisting only as long as the stimulating radiation is continued. (2) Emitting light during exposure to radiation from an external source. (3) Luminescence that is caused by the absorption of radiation at one wavelength followed by nearly immediate reradiation usually at a different wavelength and that ceases almost at once when the incident radiation stops. The common denominators for this term are a source of radiation, the absorption of this radiation, and the emission of a modified radiation that ends immediately as the source stops emitting radiation. Chemically speaking, fluorescence is brought about by absorption of photons in the singlet ground state promoted to a singlet excited state. The spin of the electron is still paired with the ground state electron. As the excited molecule returns to ground state, it involves the emission of a photon of lower energy, which corresponds to a longer wavelength, than the absorbed photon and therefore lower energy, than the absorbed radiation.

Laparoscopic approach in the treatment of malignant adrenal tumours

Abstract Introduction Malignant primary or secondary adrenal tumours are uncommon. For most of them early surgery with adrenalectomy is the only means of cure. Although controversy exists on this issue, the increasing experience in laparoscopic surgery extends the indication for laparoscopic adrenalectomy to potentially malignant and to metastatic adrenal tumours. Our aim was to evaluate the technical feasibility of laparoscopic adrenalectomy for malignant neoplasias, describing the results of our consecutive series of patients. Material and methods We retrospectively analysed 13 patients who underwent laparoscopic adrenalectomy for malignant neoplasia between March 1999 and June 2009 at the Hospital de Clinicas at the University of Buenos Aires and at the Hospital Aleman in Buenos Aires. A transperitoneal laparoscopic approach was used in all patients. The mean follow-up time was 37.9 months (2–84). Results Thirteen laparoscopic adrenalectomies were performed due to malignant neoplasia. Mean age was 55.2±12 years. The male to female ratio was 10:3. Five patients had an adrenal carcinoma, one patient a malignant phaeochromocytoma, and 7 patients had metastatic tumours. Three patients required conversion to laparotomy. Average operation time was 146.4 min. There were two perioperative complications and no mortalities. Average length of hospital stay was 4.6 days (1–35). The survival at 3 years was 46%. The cause of death was the underlying disease in all cases. Conclusion Laparoscopic adrenalectomy is a reasonable technique for malignant adrenal tumours, when the open oncological resection can be reproduced by the laparoscopic approach.

Chinese Flap in Head and Neck Surgery

Twenty patients underwent resections for head and neck cancer. The reconstructive procedure used was the free forearm flap with microsurgical technique on 22 occasions. The free forearm flap was used in its simple or composite form, with double or manifold islands, with a segment of the radius for mandible reconstruction or with two islands Joined solely by the vascular pedicle, constituting what the authors call « tandem flap », with excellent results. The procedure does not replace conventional ones, but the authors believe it should be regarded as one of the choice flaps by surgeons dedicated to this special field.