Publications by authors named "Nelson Montalvo"

Esophageal lipomatous tumors are extremely rare, and due to their nonspecific clinical manifestations, distinguishing them is nearly impossible without the aid of histopathology, immunohistochemistry, and molecular analysis. Complete resection with clear margins is the treatment of choice to avert metastasis, improve prognosis, and prevent complex complications due to the polyp growth and location. We present the case of a 70-year-old male who presented in 2023 with dysphagia due to an esophageal polyp; surgery was recommended.

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Primary hepatic liposarcoma is an extremely rare malignant tumour derived from adipocytes and is part of the group of mesenchymal tumours. We present the case of a 43-year-old Hispanic male patient with a pleomorphic hepatic liposarcoma and absence of MDM2 gene amplification. Two years and six months after surgery, the patient is asymptomatic.

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Desmoid fibromatosis is a rare, aggressive borderline lesion arising from soft tissues. Treatment will depend on the structures that the tumor has involved. Surgery with negative margins is the recommended strategy as it can usually achieve disease control; however, the tumor's location sometimes does not allow it.

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Granular cell tumors are predominantly benign soft tissue tumors originating from Schwann cells, whereas melanocytic nevi are benign proliferations of melanocytes. We present the case of a patient with the presence of both entities located in the cecum and anal canal, respectively, constituting an extremely rare coincidental finding. A 43-year-old woman was evaluated by colonoscopy for iron-deficiency microcytic anemia that had lasted for 1 year.

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Primary cutaneous diffuse large B-cell lymphoma, leg type is a rare entity accounting for 4% of all primary cutaneous lymphomas whose clinical presentation encompasses a range of possibilities. COVID-19 has caused a delay in diagnosis of malignant neoplasms and consequently, this has resulted in poorer prognoses. A 62-year-old woman presented with two smooth-surfaced, mobile, well-circumscribed, oval, skin-colored nodules approximately one-cm in diameter with nonerythematous borders on the lower third of the left leg.

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Background: Histiocytic sarcoma is a very rare monocyte/macrophage-derived hematopoietic system tumor with a poor prognosis whose diagnosis is pathologically challenging due to its extreme rarity and histological overlap with various mimicking entities in which histiocytes also predominate.

Case: We report the case of a 33-year-old male patient with hemophagocytic lymphohistiocytosis, purpuric syndrome, and significant splenomegaly. The patient underwent splenectomy; subsequent macroscopic examination revealed a spleen weighing 2065 grams with hyperemic red pulp and multiple infarcts at the periphery.

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Cutaneous myoepithelioma (CM) is a rare tumor among the primary skin neoplasms. We present the case of a patient with a diagnosis of CM in the right hypothenar region. Histological study showed a proliferation of myoepithelial cells with a solid, reticular growth pattern in a chondromyxoid stroma.

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Background: Mesonephric adenocarcinoma (MNAC) is a rare tumor of the female genital tract, which originates from mesonephric duct remnants. Its diagnosis is pathologically challenging, because MNAC may exhibit a mixture of morphological patterns that complicates the differential diagnosis.

Case Presentation: The patient in this case was a 48-year-old woman with a polypoid mass protruding into the endocervical canal.

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Secretory carcinoma (SC) is a recently described entity occurring in the salivary glands. Before its description, SC was frequently classified as acinic cell carcinoma (ACC) or adenocarcinoma, not otherwise specified. Its particular histopathological and immunohistochemical characteristics are reminiscent of breast secretory carcinoma.

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Malignant lipomatous tumors of the vulva are extremely rare. We report the case of a 53-year-old patient with a nodule on her right labium majus whose histological and immunohistochemical profile (S100 and p16) confirmed a diagnosis of vulvar myxoid liposarcoma.

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Sebaceous glands are very rarely found in the esophagus. Existing reports do not contain sufficient epidemiological, etiological, clinical, or prognostic data. Its histogenesis suggests heterotopia or metaplasia.

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Secretory breast carcinoma is an exceptionally rare mammary gland neoplasia described mainly in adult females and children of both sexes, and very rarely in the elderly. It has particular histopathological and immunohistochemical features and a favorable prognosis. We report the case of a 79-year-old Hispanic woman with a palpable breast mass.

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Hydroa vacciniforme-like cutaneous lymphoma is a very rare Epstein-Barr virus positive peripheral T-cell lymphoma affecting Asian and Hispanic children and young adults with a defective cytotoxic immune response to EBV predisposing to the development of the disease. We report on 2 Ecuadorian patients with papulovesicular and ulcerated crusted lesions on the face, upper and lower extremities and abdomen, with aggressive clinical course and, in one case, a fatal outcome. The histological and molecular profiles (immunohistochemistry and in situ hybridization) established a diagnosis of hydroa vacciniforme-like Epstein-Barr virus-encoded small RNAs + cutaneous T-cell lymphoma in both cases.

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Liposarcoma is the name given to a group of soft tissue sarcomas (STSs) with adipocytic differentiation. As a group, liposarcomas are the second most common STSs in adults. In 1951 Kozonis et al published that in the English language only four cases of liposarcomas originating in the mediastinum had been described.

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Introduction: Polymelia, or congenital duplication of a limb, is an extremely rare entity in humans, with few cases reported in the literature.

Case Presentation: We present the case of a six-month-old Hispanic boy born with a lower limb bud on the left posterior thigh.

Conclusion: The infant had a favorable outcome and evolution after surgical treatment of his supernumerary limb, with no after-effects or impairment whatsoever.

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Introduction: Prostatic blue nevus was first described as a benign lesion of uncertain and controversial histogenesis by Nogogosyan in 1963. Currently, 30 cases have been reported in the world literature.

Case Presentation: A 63-year-old Hispanic man presented with prostatism of several months' evolution.

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Introduction: Osseous metaplasia in the gastrointestinal tract is a rare phenomenon.

Case Presentation: We present the case of a 62-year-old Hispanic man with two colonic polypoid lesions, one of which, upon resection and histopathological examination, was found to be a traditional serrated adenoma with a focus of stromal osseous metaplasia.

Conclusions: Our patient's case is the third report of stromal osseous metaplasia in a traditional serrated adenoma of the sigmoid colon.

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