PEComa (neoplasia de células epiteliodes perivasculares) asociado con cáncer papilar de tiroides bilateral sincrónico / PEComa (Perivascular Epithelioid Cell Neoplasms) associated with synchronous bilateral papillary thyroid cancer

Resumen Introducción: Los tumores de células epitelioides perivasculares (PEComas) son neoplasias poco frecuentes de origen mesenquimal. Estos incluyen el angiomiolipoma epitelioide (EAML), una neoplasia con potencial maligno y cuya presentación simultánea con cáncer de tiroides es bastante rara. Presentación del caso: Hombre de 40 años con masa de crecimiento rápido en relación con polo inferior derecho de tiroides e infiltración de tráquea. La TAC abdominopélvica contrastada muestra múltiples masas renales con masa dominante en polo superior izquierdo. El estudio histopatológico de tiroides evidenció una lesión en lóbulo derecho correspondiente a cáncer papilar de tiroides (PTC) de variante de células altas y una segunda neoplasia en el lóbulo contralateral correspondiente a PTC moderadamente diferenciado de variante clásica. En riñón se encontró una lesión correspondiente a EAML, con células de aspecto epitelioide equivalentes al 40%. Discusión: El presente artículo corresponde al primero en la literatura en describir la presentación simultánea de EAML con PTC bilateral sincrónico (SBiPTC). Se describe una vía molecular común, que corresponde a la vía TSC/mTOR, la prevalencia de SBiPTC y los marcadores inmunohistoquímicos para diagnóstico de EAML.

Abstract Introduction: Perivascular Epithelioid Cell Neoplasms (PEComas) are uncommon tumors of mesenchymal origin. These ones include the epithelioid angiomyolipoma (EAML), a tumor with malignant potential and whose simultaneous presentation with thyroid cancer is quite rare. Presentation of case: Forty years old man with fast-growing mass in relation to lower right thyroid pole and tracheal infiltration. Abdominopelvic contrast-enhanced CT shows multiple renal masses with dominant mass in the left upper pole. Thyroid histopathology showed a lesion in right lobe corresponding to tall cell variant of papillary thyroid cancer (PTC) and a second neoplasm in the contralateral lobe corresponding to classical variant of moderately differentiated PTC. In the kidney was found a tumor corresponding to EAML with epithelioid aspect cells equivalent to 40%. Discussion: This article corresponds to the first in the literature to describe the simultaneous presentation of EAML with synchronous bilateral PTC (SBiPTC) and its possible association. A common molecular pathway corresponding to the TSC/mTOR pathway is described, as well as SBiPTC prevalence and immunohistochemical markers for EAML diagnosis.

Perivascular epithelioid cell tumor [PEComa] of the uterus with aggressive behavior at presentation

Perivascular epithelioid cell tumor [PEComa] is a rare mesenchymal tumor composed of histologically and immunohistochemically distinctive perivascular epithelioid cells [PECs]. Both benign and malignant tumors have been identified, but the criteria for diagnosis of malignancy have not been fully established due to the rarity of the tumor. We report on a case of uterine PEComa in a 33-year old woman with lymph node metastasis at presentation. The tumor had the characteristic histologic features of PEComa with cytologic atypia, mitotic activity of 2/10 high power field [HPF], and necrosis; it exhibited immunopositivity for HMB-45, calponin and desmin and was negative for melan-A. The patient received neoadjuvant chemotherapy, debulking surgery and adjuvant chemotherapy. No evidence of recurrence or metastasis was apparent 8 months after surgery