Prevalence of Microsatellite Instability in Gastric and Gastroesophageal Junction Cancer patients from a Latin American Country.

Background: In Colombia, gastric cancer is fifth in incidence (12.8 cases per 100,000) and third in mortality (9.9 cases per 100,000).

Solitary Fibrous Tumor in the Perianal Region: Report of Two Cases With an Atypical Location.

A solitary fibrous tumor (SFT) is a mesenchymal neoplasm of spindle cells, initially described in the pleura. The World Health Organization (WHO) classifies the solitary fibrous tumor as a neoplasm with intermediate biological potential. Diagnostic images are essential for the diagnostic and therapeutic approach in this entity.

Cutaneous Collision Tumor Associated With Porocarcinomatous and Angiosarcomatous Components: A Potential Diagnostic Pitfall.

Sarcomatoid eccrine porocarcinoma (SEP) is a very rare malignancy including epithelial and mesenchymal components exhibiting pleomorphic cells, nuclear hyperchromasia, and high mitotic activity in both elements. To date, only 6 cases of this uncommon neoplasm have been reported, corresponding to women over 70 years of age with ulcerated skin lesions. The authors describe the first sarcomatoid eccrine porocarcinoma in a 75-year-old male patient with a right hallux lesion, presenting a collision tumor with a mixed population of epithelial cells and a spindle cell angiosarcomatous mesenchymal component each expressing distinct and nonoverlapping morphologic and immunohistochemical features of epithelial and mesenchymal differentiation.

Primary diffuse large B-cell lymphoma associated with chronic osteomyelitis of the knee.

Diffuse large B-cell lymphoma (DLBCL) associated with chronic inflammation is a recently adopted category of DLBCL, which describes an aggressive B-cell lymphoma raised in the setting of non-immune chronic inflammation. Primary presentation of this subtype of DLBCL in bone is extremely rare. Here, we present the case of a 27 year old woman with DLBCL of the right distal femur, identified after a three-year history of chronic osteomyelitis.

Primary intraocular inflammatory myofibroblastic tumor with anaplastic lymphoma kinase overexpression.

The human eye can be compromised by a variated spectrum of neoplasms and reactive processes. Here we present a rare case of a primary intraocular inflammatory myofibroblastic tumor (IMT) dependent on the sclera and choroid in a 31-year-old female. The knowledge surrounding IMTs, previously included in the category of inflammatory pseudotumors, has undergone dynamic changes in the past two decades.

Primary esophageal meningioma: first literature report.

We have described a primary esophageal meningioma (MG) clinical case diagnosed in a 62-year-old woman; also, we review the literature about extracranial MGs. To our knowledge, this is the first case report of an extracranial MG occurring primarily in the esophagus. These are benign neoplasms reported classically in the central nervous system (CNS).

Early age renal synovial sarcoma.

Objective: We report a primary renal Synovial Sarcoma (SS) case and analyze its features.

Method: A 15 year old male presented with left abdominal mass and weight loss. CT scan images showed a 13 cm mass located in the lower pole of the left kidney.

[Primary malignant solitary fibrous tumor/hemangiopericytoma of the parotid gland].

Solitary fibrous tumor (SFT) was first described in the pleura by Lietaud in 1767; later in 1870, Wagner described the localized nature of this type of tumor and Klemperer and Rabin classified pleural tumors into two types: diffuse mesotheliomas and localized mesotheliomas. Recent years have seen the redefinition of this neoplasm, due to better technology; it is now proven that this neoplasm may have multiple different extrapleural origins including the head and neck regions. This diversity of locations is related to the particular mesenchymal histogenesis of SFT which allows its development from very unusual sites such as the salivary glands (SGs).

Testis T-cell lymphoma. Presentation of 2 cases and review.

Objective: To present two clinical cases of testicular T cell lymphomas and perform a review of this condition.

Methods/results: Case 1. Forty-two year old male presenting with painful mass in the right testicle which appeared 2 months earlier.

Primary yolk sac tumor of the urachus.

Introduction: Neoplasms originating from the urachus are rare. The most common urachal malignancy is adenocarcinoma, whereas extragonadal germ cell tumors, primarily of the urachus, are an extremely rare finding.

Objective: To describe a primary yolk sac tumor (YST) of the urachus in an adult.