Pablo Zoroquiain

p16ink4a Expression in Benign and Malignant Melanocytic Conjunctival Lesions

Acquired conjunctival melanocytic lesions include nevi, primary acquired melanoses (PAMs), and melanomas. Conjunctival melanoma is a malignant melanocytic neoplasm with a high metastasis and mortality rate. Usually, the diagnosis can be achieved only with routine microscopic analysis, but in some cases, the samples are small or have artifacts. In these cases, complementary studies will be helpful, but currently, there are no well-understood or studied complementary methods. Objective. To analyze the immunohistochemical expression of p16 in conjunctival melanocytic lesions and to assess its potential for differentiating between benign and malignant melanocytic lesions. Methods. Immunohistochemical study against p16ink4a (p16) was performed on paraffin-embedded sections on 45 melanocytic lesions (9 melanomas, 19 nevi, and 2 PAMs with atypia and 15 without atypia). Expression was scored according to the German immunoreactive score (IRS). Results. Expression of p16 IRS differed between nevi, PAMs, and melanomas. The mean IRS for melanomas was 3.3 ± 1.8 and was lower than those for nevi (7.63 ± 3.24; P < .05), PAM with atypia (12 ± 0; P < .05), and PAM without atypia (11 ± 1.69; P < .05). Lesions with infiltration depths lower than 2 mm showed higher levels of p16. There were no differences between favorable and unfavorable locations. Conclusion. p16 Expression in conjunctival melanocytic lesions showed an expression similar to that in skin and seems to be a good marker to differentiate nevi and PAMs from melanomas. However, additional studies of larger series and follow-up are needed to confirm these findings.

Florid reactive lymphoid hyperplasia (lymphoma-like lesion) of the uterine cervix

Lymphoma-like lesion (LLL) of the female genital tract is an older term in the literature that describes a florid reactive lymphoid proliferation that can be misinterpreted as lymphoma. Multiple causes of LLL have been suggested but most cases remain unexplained. We describe the clinicopathologic features of 6 patients with LLL involving the uterine cervix. Five patients presented with abnormal Papanicolaou test (Pap smear), and 3 patients had a biopsy procedure performed prior to detection of LLL in a loop electrosurgical excision procedure (LEEP). In each specimen, surface epithelial erosion was associated with a superficial, polymorphous lymphoid infiltrate with numerous scattered large cells, without cellular necrosis or sclerosis. Squamous dysplasia was present in 4 patients. Immunohistochemical studies revealed a mixed population of B- and T-lymphoid cells. T-cells were more numerous but B-cells and formed aggregates or sheets in areas. The large cells were predominantly B-cells positive for CD20 and negative for CD3 in all cases. CD30 was positive 3 cases, and Epstein-Barr virus-encoded RNA was positive in 3 cases. Assessment for clonality in 1 patient using polymerase chain reaction (PCR) methods revealed monoclonal immunoglobulin heavy chain (IgH) gene rearrangements. At last clinical follow-up there was no evidence of progressive or systemic disease. We conclude that LLL of the cervix has a number of etiologies and that a prior surgical procedure, present in 3 patients in this study, is another possible etiology. As has been reported by others, monoclonal IgH gene rearrangements can be detected in this entity which has a benign clinical course.

Ocular Gnathostomiasis in Brazil: A Case Report

Gnathostomiasis is a parasitic disease caused by nematode larvae ingestion of 15 known species of the genus Gnathostoma (one of the Gnathostomatidae family members). This parasite uses freshwater fish as a host and can infect - through the consumption of raw fish or their viscera - other animals such as dogs, cats, chickens, pigs, and humans. This parasitic disease, with humans acting as hosts, has been known since 1945 (India), and ocular complications have been known since 2004 (intravitreal; also described in India). Latin American countries, especially Mexico and Peru, have reported cases of the disease since 1970. The first dermatological case was reported in Brazil in 2009 (the individual had acquired the disease in Peru). This article describes the first reported ophthalmic case of the disease in Brazil and refers to a male patient, 30 years old, living in the municipality of Juruá, Amazonas State. The disease evolved within 30 days through a fistulized tumor in the inner corner of the lower eyelid. Following excision, the anatomical and histopathological examination revealed the presence of a different parasite species from other previously known genera.

Neoadjuvant chemoradiation therapy for borderline pancreatic adenocarcinoma: report of two cases

Pancreatic cancer remains as one of the most aggressive human neoplasms, with overall poor survival rates. Radical surgery of the primary lesion is the best option for treatment. Borderline resectable pancreatic tumors (BRPT), defined as partial involvement of peripancreatic vasculature, may benefit from neoadjuvant therapy. We report on the first two BRPT cases treated with neoadjuvant chemoradiation at our institution. Preoperative CT and MRI demonstrated pancreatic tumors encasing the porto-mesenteric confluence suggestive of BRPT. Patients received neoadjuvant chemotherapy (gemcitabine/cisplatin), followed by radiochemotherapy. After treatment, follow-up images demonstrated tumor downsize, allowing for the tumors to be considered then as resectable. They underwent partial pancreatoduodenectomies (Whipple procedure). In case 1, histopathology revealed a complete, margin-free resection, whereas in case 2 there was a complete pathological response, with no evidence of residual tumor. According to the literature, our initial experience using neoadjuvant chemoradiotherapy on BRPT allowed us to downsize the tumor and, subsequently, to perform a curative surgery.

Thymoma associated with hypogammaglobulinaemia and pure red cell aplasia

Thymomas are neoplasias that begin in the thymus and develop in the anterior mediastinum. They are commonly associated with a variety of systemic and autoimmune disorders, such as pure red cell aplasia, hypogammaglobulinaemia, pancytopaenia, collagen diseases, and, most commonly, myasthenia gravis. The presence of inter-current infections, especially diarrhoea and pneumonia, in the presence of lymphocyte B depletion and hypogammaglobulinaemia is known as Good’s syndrome and may affect up to 5% of patients with thymoma. While anaemia is present in 50%–86% of patients with Good’s syndrome, only 41.9% of cases present pure red cell aplasia. Concomitance of these two conditions has only been rarely studied. We report on the case of a 55-year-old man diagnosed with advanced thymoma, who, during the progression of his disease, developed signs and symptoms suggesting Good’s syndrome and pure red cell aplasia. We also performed a brief review of the literature concerning this association, its clinical characteristics, and treatment.

Apocrine adenocarcinoma of the eyelid

The Henry C. Witelson Ocular Pathology Laboratory, McGill University, 1001 Boul Decarie, Montreal H4A 3J1, Canada 2Department of Ophthalmology, King Saud University, PO Box 245, Riyadh 11411, Saudi Arabia 3Department of Ophthalmology, McGill University, 5252 Boul de Maisonneuve ouest, Montreal H4A 3S5, Canada Correspondence to: Pablo Zoroquiain. The Henry C. Witelson Ocular Pathology Laboratory, McGill University, 1001 Boul Decarie, Montreal H4A 3J1, Canada. zoroquiain@gmail.com Received: 2015-06-14 Accepted: 2016-03-07

Early-Onset EBV-Positive Post-transplant Plasmablastic Lymphoma Arising in a Liver Allograft A Case Report and Literature Review

We report a case of a 51-year-old man who received a cadaveric liver allograft for autoimmune and hepatopulmonary syndrome. The patient was admitted with symptoms of progressive vomiting and diarrhea 16 months after transplantation. Laboratory studies showed abnormal liver functions, and abdominal magnetic resonance imaging (MRI) showed a 76-mm heterogeneous mass in the liver. Histological examination showed a malignant lymphoid neoplasm with plasmablastic features. Plasmablastic lymphoma (PL) is rare in the post-transplantation period. To the best of our knowledge, only 25 well-documented cases of posttransplant PL, including ours, have been described.

SIRT2 Expression Is Higher in Uveal Melanoma than In Ocular Melanocytes

Purpose: Sirtuins (SIRTs) are the family of proteins associated with the cell cycle and that correlate with cancer development and progression. SIRTs have never been studied in uveal melanocytes. The aim of this study is to characterize the expression of SIRT2 in uveal melanoma (UM) cases and compare it with the expression of SIRT2 in melanocytes of the uveal tract of normal human eyes (NHE). Methods: Twenty-one formalin-fixed, paraffin-embedded human UM cases were immunostained for SIRT2, along with 15 NHE obtained from the Eye Bank of Canada. Results: SIRT2 expression was higher in melanomas than in normal melanocytes of both tumor and donor eyes (p < 0.0001). No significant difference in SIRT2 expression was found when comparing normal melanocytes in UM and NHE cases. Conclusions: SIRT2 expression is significantly stronger in UM cells than in normal ocular melanocytes. This finding may indicate an important role of SIRT2 as a prognostic marker in UM progression. SIRT2 should also be investigated as a possible therapeutic target.

Rinosporidiosis conjuntival diagnosticada mediante estudio histopatológico

Escolar de 11 anos, de sexo femenino, proveniente de la Region del Bio-Bio, sin antecedentes de viajes, consulto por ojo rojo, blefaritis y epifora sanguinolenta; al examen oftalmologico revelo una pseudomembrana. La sospecha clinica fue de una conjuntivitis folicular. Se realizo la remocion quirurgica de la lesion y en el estudio histopatologico se observaron lesiones caracteristicas de rinosporidiosis, correspondiente a quistes de 50-150 μm con pared quitinosa y numerosas endosporas. La rinosporidiosis es una infeccion causada por Rhinosporidium seeberi, que afecta con mayor frecuencia la cavidad nasal, pero puede tambien afectar el ojo, aparato urogenital y la via aerea, entre otros. Es considerado endemico en paises de Asia y Africa, pero dado el aumento de viajes a estas regiones es importante reconocer este agente como causal de polipos en la zona nasal y ocular.

Atypical presentation of pseudomembranous colitis localized in adenomatous polyps

The most frequent cause of pseudomembranous colitis is Clostridium difficile (C. difficile) infection. This type of colitis is characterized by an endoscopic pattern of numerous small, yellowish or whitish plaques diffusely distributed, which typically compromises the rectum extending to proximal colon. Occasionally, the pseudomembranes compromise only the transverse or right colon, but their exclusive localization over polyps has not been reported. In this case report we have described a patient with symptoms compatible with C. difficile infection and positive for C. difficile toxigenic culture. Colonoscopy examination showed two small polyps with a whitish surface, and histopathological analysis confirmed them to be pseudomembranes over tubular adenomas. The rest of the colonic mucosa was normal and no other cause was demonstrated. We suggest that this particular distribution might be due to a higher affinity for dysplastic cells such as adenomatous polyps of colon by C. difficile and/or its toxins.