The exponential development of immunohistochemistry has become a fundamental piece for the diagnosis, prognosis and treatment of different pathologies, for this reason, the knowledge of histotechnology processing will allow the timely detection of those variables in the phases of the process that influence the expression of immunomarkers that would generate diagnostic errors, loss of economic and biological resources. OBJECTIVE: to establish the preanalytical handling conditions: fixative pH, fixation time, previous time without fixation, in the expression of immunohistochemical markers. METHODS: an updated documentary review of publications in the database of indexed journals PUBMED and others was carried out in relation to the pre-analytical process, tissue processing in the Pathological Anatomy laboratory, immunohistochemical technique, relationship between the result of markers of Immunohistochemistry and variations in fixative pH, fixation times and times prior to fixation since 2011, obtaining 57 publications which were consolidated and presented in this study. CONCLUSION: the importance of the pre-analytical process in its different phases is demonstrated, and its effect to obtain adequate lamellae for a correct analysis. Optimum fixation and fixation times at pH are vital in the pre-analytical phase.

Introduction: The histological classification of surgery tumors by the World Health Organization (WHO) is based on histogenetic principles, and it divides surgery tumors according to their derivation of epithelial cells, germ cells and mesenchymal cells (stroma and sex cord). Objective: to describe the clinical- epidemiological characteristics of clear cell ovarian carcinoma. Methodology: we made a review of the bibliography on the subject and presented the results. Results: Clear cell carcinoma (CCC) of the ovary has been reported to have a worse prognosis than all other neoplasms in this group. Taking this into account, this presentation of a case attended in our institution has been carried out, with an effective treatment, valid for the survival of the patient and a good quality of life. Conclusions: it is an epithelial ovarian tumor frequently resistant to conventional chemotherapy.

Introduction: Cervical cancer is one of the leading causes of cancer death among women. Neuroendocrine tumors are aggressive and develop from endocrine cells in various organs, including the female genital tract, and specifically the uterine cervix. Objective: to describe the clinical- epidemiological characteristics of small cell carcinoma. Methodology: we made a review of the bibliography on the subject and presented the results. Results: They account for 0.9%–1.5% of all tumors of the uterine cervix and generally affect women of reproductive age. Given the rarity of the disease, limited data are currently available regarding the biology, clinical behavior, and management of such aggressive tumors. The etiopathogenetic association between cervical small cell carcinoma (SCCC) and high- risk HPV infections has been well documented in some studies and has a much worse prognosis compared with other histological types of cervical carcinoma. The treatment modalities of SCCC and small-cell lung cancer are similar due to similar biological behavior. Chemotherapy is an important component of multimodal therapy. We made a case presentation of a patient with diagnosis of SCCC with an overall survival of six years, well above the average international survival. Conclusions: research should continue to reach consensus on the appropriate treatment.

Abstract Introduction: Hepatoid carcinoma of the pancreas (CHP) is extremely rare. It is a primary extrahepatic neoplasm that resembles hepatocellular carcinoma in terms of morphology and immunohistochemistry. In the pancreas, hepatoid carcinoma could be pure or mixed with other histological components such as neuroendocrine tumor or pancreatic ductal adenocarcinoma. Objective: to describe the clinical- epidemiological characteristics of hepatoid carcinoma of the pancreas. Methodology: we made a review of the bibliography on the subject and presented the results. Results: Induction of hepatocytes in the pancreas has been performed in several animal models. A case is presented at our stately institution T3 N0 M1, Clinical Stage IV, which received oncospecific treatment with chemotherapy, GEMOX scheme (12 cycles), with good tumor response, which at 6 months is revalued with CT that shows moderate ascites, second-line treatment with Gramont scheme (6 cycles) is decided according to response. Conclusions: it is a rare entity whose management is based on chemotherapy.

Introduction: Thromboembolic disease encompasses two major entities that are deep vein thrombosis and pulmonary thromboembolism together constitute the second leading cause of death in cancer patients and sometimes the first manifestation of underlying hidden neoplasm. It occurs most frequently in stomach, pancreas, gynecological, bladder, testicle and lung tumors, where it appears in up to 14% of cases and can increase further with treatment. For its management it is recommended to evaluate the risk and subsequently the use of low molecular weight heparins, although other options can be used. Objective: to explain the epidemiological ant pathophysiological elements and the treatment of thromboembolic disease in patients with lung cancer. Methodology: A review and analysis of the bibliography was carried out, detailing incidence, etiology in cancer patients and main management options. Conclusions: Its proper diagnosis and timely management will ensure for patients a better quality of life and greater overall survival, and for hospital institutions a reduction in significant expenditures.

Introduction: Adrenocortical carcinoma is a rare entity with an annual incidence of 1-2 cases per million people. Oncocytic neoplasms that arise in the adrenal glands are extremely rare, and are usually discovered as non- functional and mostly benign tumors. Objective: to describe the clinical- epidemiological characteristics of adrenal cortex secretor tumor. Methodology: we made a review of the bibliography on the subject and presented the results. Results: Since the first description confirmed by electron microscopy in 1986, approximately 147 cases have been reported in the literature, most often described as incidental findings. The case is presented of a woman with adrenal cortex secretor tumor successfully treated, with disappearance of the initial clinic and who remains with excellent quality of life. Conclusions: it is a rare entity whose management is mainly based on surgery.

Introduction: Among hereditary hemolytic anemias, hereditary spherocytosis (HS) is the one that occurs most frequently. Autosomal dominant (AD) and autosomal recessive (AR) inheritance patterns account for 75% and 25% of all HS cases, respectively. The prevalence of HS varies among different racial and ethnic regions, affecting approximately 1 in 2,000 people in Northern Europe, North America, and Japan, but is less common in African Americans and Southeast Asia. Cholestatic syndrome is usually one of the most common complications and occurs in patients between 10 and 30 years of age, although younger patients can also present it and cholecystectomy is a safe and effective radical treatment for this pathology. Objective: To describe the clinical evolution and the surgical management of the patient with spherocytosis who develops a cholestatic syndrome as one of the most frequent complications of this pathology. Materials and methods: The theoretical support of this clinical case, corresponding to the most updated information up to 5 years ago, was obtained through the literature search and access to scientific articles, books, magazines, and other physical and virtual documents through of professional seekers in the field of health. Conclusions: The evolution of the complications of hereditary spherocytosis, especially cholestatic syndrome, led to several days of hospital stay, but in most cases, they are usually resolved favorably in this case by means of laparoscopic cholecystectomy, satisfactory results were obtained and discharge. 22 days after admission.