[Clinicopathologic characteristics of 127 cases of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) studied in an oncology hospital]. / Características clínico-patológicas de 127 casos de neoplasias neuroendocrinas del aparato gastrointestinal y páncreas (NNE-GEP) estudiadas en un hospital de oncología.

BACKGROUND: Neuroendocrine tumors (NETs) present all along the length of the gastrointestinal (GI) tract, from the esophagus to the anus, and they also present in the pancreas. AIMS: To classify NETs according to the WHO 2010 criteria and to evaluate their anatomic distribution and clinicopathologic characteristics. MATERIAL AND METHODS: A search was carried out in the hospital pathology archives of all the cases diagnosed with carcinoid tumor and neuroendocrine carcinoma of the GI tract and pancreas studied over a period of 11 years (1999-2010). The cases were reclassified according to the WHO 2010 criteria. The clinical case records of each patient were reviewed. RESULTS: The study group was made up of 127 cases (68 men; 59 women). Age ranged from 24 to 85 years with a median of 52 years. A total of 113 (89.00%) tumors occurred in the GI tract and 14 (11.00%) in the pancreas. Tumor size varied from 0.4cm to 9cm (median: 2.5cm). GI tumor histologic grades were: 54.00% grade 1; 31.00% grade 2; and 15.00% grade 3. Pancreatic tumor histologic grades were: 43.00% grade 1; 36.00% grade 2; and 21.00% grade 3. Ki-67 overexpression was correlated with tumor grade (22.00% grade 3 vs 2.50% grade 1). CONCLUSIONS: Histologic grade of the gastroenteropancreatic neuroendocrine tumors (GEP-NETs) is one of the most important prognostic factors. The term carcinoid should be eliminated because it does not reflect the biological behavior of these tumors.

Tumor size as predictor of microinvasion, invasion, and axillary metastasis in ductal carcinoma in situ.

Ductal carcinoma in situ (DCIS) represents a small number of cases in countries with inadequate breast cancer screening programs, and in the majority of cases is diagnosed as a palpable lump. It has been proposed that DCIS with palpable lump > or = 2.5 cm can be associated with microinvasion or invasive carcinoma and risk of axillary metastasis. The purpose of the present study is to evaluate incidence of microinvasion, invasion, and the role of lymphatic mapping and sentinel lymph node biopsy in DCIS > or = 2.5 cm. We conducted a retrospective analysis of patients with histologically proven incisional, excisional, or core biopsy of DCIS lump > or = 2.5 cm at a tertiary-care hospital. All patients underwent lymphatic mapping with sentinel lymph node biopsy.A total of 24 patients were included with average tumor size of 4 cm (range, 2.5-6 cm); 29% had microinvasive and 12.5% had invasive disease, three patients (12.5%) had positive sentinel lymph node, all had micrometastasis, and no metastasis were found in non-sentinel lymph nodes. Incidence of microinvasion and invasion were directly related with tumor size (10% for DCIS tumor size of 2.5-3.5 cm, 57% for 3.6-4.5 cm, and 71% for tumors between 4.5 and 6 cm). In addition, axillary metastasis incidence had a direct relationship with tumor size. (0% in 2.5-3.5-cm tumor size, 14% for 3.6-4.5 cm, and 28% in DCIS between 4.6 and 6.0 cm). The present study shows high incidence of microinvasion and invasion in DCIS diagnosed in tumors > or = 2.5 cm and supports the importance of axillary evaluation in patients with tumors >3.5 cm by means of lymphatic mapping and sentinel lymph node biopsy.

[Primary sterility and cervical pregnancy. A case report]. / Esterilidad primaria y embarazo cervical. A propósito de un caso.

Fortunately cervical pregnancy, an ectopic gestation that frequently represents obstetric urgency, is a rare entity. We present here the case of a woman who developed cervical pregnancy despite no risk factor associated with ectopic pregnancy was identified. The patient came to the office because of primary sterility of 4 years of evolution. Among her background she reported previous cervical surgery due to benign pathology. She reached pregnancy after medical and surgical treatment. In the week eleven of gestation, the patient presented to the hospital with clinical symptoms of abortion. An ultrasound revealed abdominal pregnancy. Laparotomy was "white", cervix was found enlarged with the external orifice closed, suggesting cervical pregnancy. Conservative treatment consisted in cervical evacuation, endometrial curettage and vaginal tampon. She evolved satisfactorily. We do not know about any previous report of cervical-pregnancy associated with cervical surgery and sterility. We also recognize the need to increase the number of similar cases to generalize results. Thus, it is important to highlight in this case the absence of known risk factors for cervical pregnancy and the background of cervical surgery and sterility. Therefore, we recommend to search for antecedents of cervical surgery and sterility when cervical pregnancy is suspected.

Esterilidad primaria y embarazo cervical. A propósito de un caso / Primary sterility and cervical pregnancy. A case report

Fortunately cervical pregnancy, an ectopic gestation that frequently represents obstetric urgency, is a rare entity. We present here the case of a woman who developed cervical pregnancy despite no risk factor associated with ectopic pregnancy was identified. The patient came to the office because of primary sterility of 4 years of evolution. Among her background she reported previous cervical surgery due to benign pathology. She reached pregnancy after medical and surgical treatment. In the week eleven of gestation, the patient presented to the hospital with clinical symptoms of abortion. An ultrasound revealed abdominal pregnancy. Laparotomy was "white", cervix was found enlarged with the external orifice closed, suggesting cervical pregnancy. Conservative treatment consisted in cervical evacuation, endometrial curettage and vaginal tampon. She evolved satisfactorily. We do not know about any previous report of cervical-pregnancy associated with cervical surgery and sterility. We also recognize the need to increase the number of similar cases to generalize results. Thus, it is important to highlight in this case the absence of known risk factors for cervical pregnancy and the background of cervical surgery and sterility. Therefore, we recommend to search for antecedents of cervical surgery and sterility when cervical pregnancy is suspected.

Leiomyoma of the urethra in a Mexican woman: a rare neoplasm associated with the expression of estrogen receptors by immunohistochemistry.

BACKGROUND: Leiomyoma of the female urethra is a rare condition, although it can occur anywhere along the genitourinary tract. METHODS: We report on a 22-year-old woman found to have a urethral mass detected in our hospital delivery room. Examination showed a 6 X 5-cm mass at the urethral meatus. RESULTS: Pathologic examination revealed urethral leiomyoma. Immunohistochemistry confirmed leiomyoma with positive staining for vimentin, desmin, and actin. Immunoreactivity for estrogen receptors was also detected. CONCLUSIONS: Because this lesion was discovered while the patient was pregnant and it showed immunoreactivity for estrogen receptors, it is suggested that increased estrogen levels could accelerate smooth muscle growth.

[Laryngeal plasmacytoma]. / Plasmocitoma de laringe.

Solitary plasmocytoma is a rare presentation of plasma cell dyscrasia. About 1% od the patients can present with a extramedullary plasmocytoma; although bone presentation is the most frequent, in some cases, soft tissue can be affected. Radiotherapy remain as the election treatment. A case of primary plasmocytoma of the larynx is presented. The patient is alive after radiotherapy. Discussion about the clinical differentiation and also a review of the literature is present.

[Nephrogenic adenoma of the urinary bladder. A lesion that can be confused with carcinoma. Report of 4 cases]. / Adenoma nefrogénico de la vejiga urinaria. Una lesión que puede ser confundida con carcinoma. Reporte de cuatro casos.

Nephrogenic Adenoma (NA) was first illustrated in 1949 by Davis, who described a case he interpreted as a "hamartoma". One year later Friedman and Kuhlenbeck described eight further examples in detail and named this lesion nephrogenic adenoma. This process is generally accepted to be metaplastic. At cystoscopy and on microscopic examination nephrogenic adenoma may simulate a neoplasm. The clinical and pathologic findings in four patients are described. The patients were two women and two men 20-60 years of age. All of them had a history of some inciting injury (infection/calculus). The four cases were initially misdiagnosed as a carcinoma. Several features of NA may cause particular diagnostic difficulty. Tiny tubules may simulate signet ring cells, the haphazard distribution of the tubules or single cell growth may also simulate the appearance of an invasive adenocarcinoma. A variety of clinical and pathologic differences should enable the distinction of these lesions. Although this is occasionally difficult. An emphasis here is placed on the diagnostic problems that they may pose for the surgical pathologist. Clinicians and pathologists should be aware about this type of lesions in order to avoid pitfalls in the diagnosis and treatment of them.

Intrarenal schwannoma: a report of four cases including three cellular variants.

Renal schwannomas are extraordinarily rare neoplasms; only six have been reported, the majority of which occurred in the renal pelvis. We report the clinical and pathologic features of four additional cases. The resected kidney in all patients contained a well-demarcated, yellow-tan, smooth, and bulging intraparenchymal tumor (mean size, 9.7 cm; range, 4 to 16 cm). Microscopically, three cases were classified as cellular schwannomas, and one was a usual-type schwannoma, with degenerative nuclear atypia. By immunohistochemistry, all tumors were strongly S-100 protein positive and negative for pan-cytokeratin, CD57, smooth muscle actin, desmin, and CD34. Epithelial elements were not noted in the tumors, and there was no history of any clinical syndromes in these patients. Analysis of the four cases showed the mean age at presentation to be 47 years (range, 18 to 84 years), with no sex predisposition (two men, two women). Most patients were asymptomatic, and all received a diagnosis of renal cell carcinoma and treated as having such. Recognition and awareness of these rare, benign tumors will assist in the differential diagnosis of spindle cell tumors of the kidney and prevent their misdiagnosis as sarcomatoid carcinomas of the kidney or renal sarcomas. Our study, the largest series to date of renal schwannomas, demonstrates a predilection for the cellular variant in the kidney, documents that these tumors may present in the nonhilar region of the kidney, and provides clinical evidence of their benign biologic behavior.

[Benign epithelial inclusions in pelvic lymph nodes. 2 case reports]. / Inclusiones epiteliales benignas en ganglios linfáticos pélvicos. Informe de dos casos.

A large number of lymph node inclusions excluding endometriosis have been described in a variety of anatomical sites; they are usually epithelial and only rarely non-epithelial. Their presence can give rise to an erroneous diagnosis of metastasis. Recently the staging laparotomy has become a frequent procedure in the management of neoplasms of the female genital tract, and involves abdominal lymphadenectomy, inspection of the peritoneal surface, multiple biopsies and the resection of suspicious lesions. During the surgery, and among the lesions excised, the occasional presence of lymph node inclusions can lead to a diagnostic error. In order to avoid this problem, it is necessary to be adequately informed about these inclusions, including their anatomic sites, their histologic characteristics and the knowledge that they can present in lymph nodes related to an inflammatory process or a tumour. This revision is to alert pathologist towards a group of lesions which can imitate metastatic carcinoma, and specially towards those inclusions which present together with malignant neoplasias of the female genital tract. Recently we received two cases of pelvic lymph nodes, initially diagnosed as metastatic carcinoma, and eventually found to correspond to mesothelial cell hyperplasia in one case, and to lymph node inclusions in the other.

[Gastric stromal tumor with myxoid degeneration. Report of a case and review of the literature]. / Tumor estromal gástrico con degeneración mixoide. Reporte de un caso y revisión de la literatura.

BACKGROUND: Gastrointestinal stromal tumors (GIST's) represent a heterogeneous group of neoplasms that have as their common histologic denominator an immature proliferation of epithelioid or spindle cells. Although originally believed to represent atypical variants of leiomyoma or leiomyosarcoma, recent studies have demonstrated that only a subset of such tumors actually display well developed immunohistochemical, ultrastructural features of smooth muscle differentiation. Most gastrointestinal mesenchymal tumors are of uncertain histogenesis. Current studies have shown a striking morphological and immunophenotypic similarities of these tumors with the interstitial cells of Cajal. And that they may originate from stem cells that differentiate toward a pacemaker cell phenotype. Most GIST's have a co-expression of Kit (CD117) or CD34, which is also express in interstitial cells of Cajal. OBJECTIVE: This review will attempt to summarize the current knowledge and understanding of these lesions based on review of the literature, with an analysis of the criteria for distinguishing between benign and malignant tumors. METHOD: We report a Gastrointestinal Stromal Tumor of the stomach with prominent cystic degeneration. The patient had diarrhea, abdominal pain and was found to have abdominal mass. X-ray and computed axial tomography examination showed a lesion that seems to be a pancreatic cystic lesion. At laparotomy a large intramural tumor located in the stomach was found. Histologically, the lesion was composed of epithelioid and spindle cells embedded in an abundant myxoid stroma. Tumor cells showed positive staining for vimentin and CD34 positive. We conclude that the diagnosis of gastrointestinal stromal tumor whit prominent cystic degeneration can be made in this case.