Alfredo Romero-Rojas

Spindle cell oncocytoma of the adenohypophysis

Spindle cell oncocytoma of the adenohypophysis (SCO) is defined as spindle to epithelioid cells with oncocytic appearance presenting in the adenohypophysis. In contrast to pituitary adenomas, the SCO does not show immunoreactivity for neuroendocrine markers and pituitary hormones but co-expressed vimentin, S-100 protein, epithelial membrane antigen (EMA), and antimitochondrial antibody MU213-UC clone 131-1. We describe an SCO in an adult, a 42-year-old woman whose magnetic resonance (MR) images documented an intrasellar lesion located in the hypophysis. Histopathological examination showed a tumor composed predominantly of spindle cells. Immunohistochemical studies showed positivity for vimentin, S10, EMA, and antimitochondrial antibody MU213-UC clone 131. Cytokeratin (CK) (AE1/AE3), glial fibrillary acidic protein (GFAP), chromogranin, synaptophysin, PGP9.5, CD57, desmin, D2-40, smooth muscle actin (SMA), Bcl-2, progesterone receptor, and CD34 were negative. Neuropeptides were negative. With electron microscopy, the neoplastic cells appear filled with mitochondria, well-formed desmosomes, but lacked secretory granules. SPO is a rare non-endocrine neoplasm of the adenohypophysis with benign biological behavior corresponding to WHO grade I.

Ectopic thyroid tissue in the adrenal gland: a report of two cases with pathogenetic implications.

BACKGROUND Ectopic thyroid tissue is usually found anywhere along the embryonic descent pathway of the medial thyroid anlage from the tongue to the trachea (Wölfler area). However, ectopic thyroid tissue in the adrenal gland (ETTAG) is not easy to understand on the basis of thyroid embryology; because it is so rare, the possibility of metastasis should first be considered. Here, we describe two cases of ETTAG with pathogenetic implications and review the associated literature. PATIENT FINDINGS Two cases of ETTAG presented as incidental cystic adrenal masses in adult females, one having a congenital hernia of Morgagni. The ETTAG was histologically indistinguishable from normal orthotopic thyroid tissue, and its follicular nature was confirmed by immunohistochemical positivity for thyroglobulin, thyroperoxidase, thyroid transcription factor-1 (TTF-1/Titf-1/Nkx2.1), cytokeratin AE1/AE3, cytokeratin 7, pendrin, human sodium iodide symporter, paired box gene 8, and forkhead box E1 (TTF-2), as well as positivity for the messenger RNA of the thyroglobulin gene by in situ hybridization analysis. No C cells (negativity for calcitonin, chromogranin, and synaptophysin) were present. Neither BRAF nor KRAS mutations were detected with real-time polymerase chain reaction analysis. Further work-up did not show evidence of thyroid malignancy. SUMMARY ETTAG is a rare finding, with only seven cases reported; women are much more frequently affected than men (8:1), and it usually presents in the fifth decade (mean age 54, range 38-67) as a cystic adrenal mass incidentally discovered on abdominal ultrasonography and/or in computed tomography images. ETTAG is composed of normal follicular cells without C cells. The expression of some transcription factors (TTF-1, paired box gene 8, and FOXE1) involved in development and/or migration of the medial thyroid anlage is preserved. Coexistence of a congenital hernia of Morgagni in one patient suggests an overdescent of medial thyroid anlage-derived cells in its pathogenesis. CONCLUSION Although ETTAG pathogenesis remains unknown, the lack of C cells together with the coexistence of a congenital defect of the anterior diaphragm (hernia of Morgagni) in one of our patients could suggest an overdescent of medial thyroid anlage-derived cells in the origin of this heterotopia.

Glioblastoma Metastasis to Parotid Gland and Neck Lymph Nodes: Fine-Needle Aspiration Cytology with Histopathologic Correlation

Glioblastoma (GBM) is one of the most highly aggressive neoplasms of the central nervous system. Extra-cranial metastases in GBM are rare. Here we present the case of a 26-year-old man with extra-cranial metastasis of a frontal lobe GBM to the parotid gland, cervical lymph nodes, and bones, with initial diagnosis made by fine needle aspiration cytology (FNAC) of the parotid gland. FNAC is a reliable technique in the study of primary and secondary parotid gland neoplasms, allowing a presumptive diagnosis in difficult cases. We correlate the cytologic, histopathologic, and immunohistochemical findings in this case and discuss previous literature reports.

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). In this particular site, this neoplasm is very infrequent and most of reported cases refer to benign disease, with just one case informed so far of primary malignant SFT.

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. Case report. A 44-year-old woman presented with 6 months of pelvic pain associated with a sensation of progressive mass growth. At the time of tumor resection, the tumor was found to be attached by a pedicle to the dome of the bladder, with no injury to the adjacent organs. Pathological study showed a neoplasm with epithelioid cells, pseudocysts, a myxomatous background, and Schiller-Duval body formations. Immunohistochemistry stains showed positivity to AE1/AE3, α-1-fetoprotein, and α-1-antitrypsin and negativity to other markers. Conclusion. An unusual case of a YST in the urachus is presented. This is the first reported adult case based on the authors’ bibliographic search.

CD99 is expressed in chordoid glioma and suggests ependymal origin

Chordoid glioma (CG) is a neoplasm of the central nervous system (CNS), first described in 1995 by Wanschitz et al. [1], which is located exclusively in the third ventricle and hypothalamic region [2]. The origin of the CG is unclear, as it has characteristics similar to meningioma or chordoid chordoma, which is why some authors consider it a variant of these neoplasms [3]. It expresses glial fibrillary acidic protein (GFAP), which has led authors [4] to consider it to have a glial nature. In 1998 the CG was first described as a particular clinicopathologic entity, and since then few cases have published. Ependymal differentiation has been proposed as possible lineage of origin of this neoplasm [3, 5]. Recently, the use of CD99 has been proposed to support ependymal differentiation [6, 7]. We evaluate immunochemical expression of CD99 in the differential diagnosis of a case of CG. Case report

Thyroid-type solid cell nests in struma ovarii.

Solid cell nests (SCNs) of the thyroid are single or multiple foci of solid and/or cystic clusters of squamoid cells (main cells) with a minor proportion of C-cells, found in the normal thyroid. The SCNs have also been reported in the heart as an ultimobranchial heterotopia. Here, the authors describe a case of thyroid-type SCNs associated with struma ovarii. Main cells were positive for simple and stratified epithelial-type cytokeratins, carcinoembryonic antigen, carbohydrate antigen 19.9, p63, bcl-2, and galectin-3. The neuroendocrine cell population was positive for chromogranin A and synaptophysin but negative for calcitonin, suggesting a common ancestor cell capable of dual differentiation toward thyroid follicular cells and hindgut-type endocrine cells. The existence of thyroid-type SCNs in struma ovarii could be easily understood by considering the struma ovarii as a teratoma; at the same time, these findings also support the idea of a close histogenetic link between the main cells of SCNs and thyroid tissue.

Primary gliosarcoma of the brain: radiologic and histopathologic features.

Gliosarcoma is a rare central nervous system (CNS) neoplasm with biphasic glial and non-glial malignant components. Here we describe the radiologic and histopathologic features observed in five cases of primary gliosarcoma. The mean age at diagnosis in the studied patients was 54.2 years; these patients were predominantly males (male: female ratio = 4:1). At diagnosis all patients had several clinical deterioration. The most common symptoms of presentation were: headache (5/5 cases), seizures (4/5 cases) and hemiparesis (1/5 cases). All the tumors were large (mean major diameter = 4.12±1.64 cm) at diagnosis as evidenced in computer tomography (CT) scans and magnetic resonance images (MRIs), with preferential involvement of the temporal lobe and frequent associated deviation of the midline structures. Other common characteristics identified on CT scans and MRIs were partial contrast medium uptake with annular pattern (5/5 cases), peripheral edema (5/5 cases), and central calcification (3/5 cases). In additional a peak of dye uptake was observed (4/5 cases) on MRI spectrometry. In the histopathology, the glial component showed malignant astrocytes, with high Ki67 (>60%) and p53 positivity; the sarcomatous components displayed pleomorphic spindle cells similarly with p53 positivity and high Ki67 (75–90%) in all cases. Dedifferentiation to pleomorphic sarcoma (two cases), fibrosarcoma (one case), leiomyosarcoma (one case) and MPNST (one case) were documented. All patients received radiotherapy/chemotherapy and had a median overall survival of ten months. The study of radiologic and histopathologic features in primary gliosarcomas of the brain is a priority to achieve early diagnosis that can be translated to better outcomes. Here we describe the radiologic and histopathologic features observed in a group of gliosarcoma patients with variable histopathologic dedifferentiation.

Histopathological and immunohistochemical profile in anaplastic gangliogliomas

BACKGROUND The anaplastic ganglioglioma (AG) is the high-grade counterpart of ganglioglioma, a rare mixed tumor composed of neuronal/ganglion and glial cells. MATERIALS AND METHODS We describe the histopathology and immunohistochemistry in 7 cases of AG and correlate them with the clinical and radiological features. RESULTS Our AG patients correspond to 2.5% of the central nervous system tumor patients evaluated in our institution. The mean age at presentation was 25.7 years, with a male predominance. The most common clinical presentation was generalized tonic-clonic seizures (3/7 cases), in correlation with frequent cortical/subcortical location (6/7 cases). Histopathologically, all our cases showed high-grade features in glial (glial fibrillary acid protein-positive) and neuron-ganglion cells (synaptophysin, PGP-9.5, neurofilament, NSE and CD56-positive), as well as moderate cellularity, frequent mitotic figures and a Ki-67 labeling index >5%. All our patients had poor survival. CONCLUSION We found that a typical histopathological and immunohistochemical profile is constant and can be useful in early diagnosis of these aggressive neoplasms.

Tumor maligno de la vaina del nervio periférico (MPNST) glandular de la órbita: primera descripción de la literatura de localización orbitaria en un paciente con neurofibromatosis tipo 1

Resumen Introduccion El tumor maligno de la vaina del nervio periferico (MPNST, por sus siglas en ingles Malignant Peripheral Sheath Tumor), es una neoplasia maligna originada en las celulas de Schwann de la vaina de revestimiento de los nervios perifericos. Esta neoplasia puede presentar componentes heterologos benignos o malignos, con diferenciacion divergente, como la diferenciacion glandular. Objetivo Describir el primer caso en la literatura de MPNST glandular maligno localizado a nivel orbitario y realizar una revision sobre esta neoplasia. Caso clinico Nino de 9 anos de edad, con diagnostico de NF1, quien presento exoftalmos ocular, dolor retro-ocular, cefalea, asimetria facial y descenso del globo ocular derecho de 1 ano de evolucion; a quien se documento masa solida orbitaria, delimitada, lobulada, que se proyecta al parenquima cerebral frontal y temporal en los estudios de tomografia computarizada y resonancia magnetica. La lesion se abordo en forma fronto-orbito-cigomatica con reseccion completa de la misma. Posteriormente, se hizo una plastia dural en base de craneo y reconstruccion con malla de titanio. Actualmente el paciente se encuentra asintomatico despues de 6 meses de tratamiento. En el estudio anatomopatologico se observo una neoplasia maligna bifasica, reactiva en los elementos mesenquimales para S100, PGP 9.5, neurofilamentos y vimentina. El componente glandular fue positivo para AE1/AE3, EMA, CEA y focalmente para CD57. Se observo ademas reactividad para cromogranina, sinaptofisina, serotonina y somatostatina. Se realizo el diagnostico de MPNST glandular de la orbita. Conclusion Se describe el primer caso de MPNST glandular localizado en la orbita, el cual se presento en un nino con NF1. Esta neoplasia extremadamente infrecuente debe ser tenida en cuenta en el estudio de lesiones bifasicas malignas, ya que su diagnostico es de peculiar importancia debido al pesimo pronostico de los pacientes afectados.