[An intimal sarcoma of the pulmonary artery. An immunohistochemical study]. / Sarcoma intimal de la arteria pulmonar. Estudio inmunohistoquímico.

Pulmonary artery intimal sarcomas tend to be presented with symptoms of pulmonary thromboembolism and grow regionally, with little capacity to metastasize. They probably originate from subendothelial cells, that become myofibroblasts. Knowledge of it is important to establish a presurgery diagnosis, with the possibility of a total resection, the only useful treatment until now. We report a case of a pulmonary artery primary sarcoma, in a 73 year old woman, admitted with hemoptysis and pleuritic chest pain, who died ten days after. Autopsy revealed an intraluminal mass at the pulmonary artery trunk, without regional nor distance involvement. Microscopic study showed a pleomorphic tumor with spindle and epithelioid cells, positive for actin, desmin and vimentin. All these data support the diagnosis of primary intimal sarcoma of the pulmonary artery. We want to emphasize the myogenic differentiation of the tumor, uncommon in previously reported cases.

[Alveolar rhabdomyosarcoma with massive infiltration of the bone marrow as its initial manifestation]. / Rabdomiosarcoma alveolar con infiltración masiva de medula ósea como manifestación inicial.

We report a case of alveolar rhabdomyosarcoma (AR) with massive infiltration of bone marrow at presentation, and initial diagnosis in bone marrow aspirate. A 35 year old man presented with a submandibular mass, and hematomas after mild traumatisms. Peripheral blood showed thrombocytopenia and a normocytic anaemia. Bone marrow film showed diffuse involvement by undifferentiated blasts with rhabdomyoblastic features. Subsequent biopsy of submandibular lymph node confirmed the diagnosis with positivity for specific muscle actin and desmin, and negativity for lymphoid markers. Initial presentation of AR with extensive bone marrow involvement is extremely rare, and it could lead to wrong diagnosis and treatment of acute leukaemia, with the serious consequences that this would have. Immunohistochemical study and morphologic differential features can be of great diagnostic help.

[Extramedullary anaplastic plasmacytoma]. / Plasmocitoma anaplásico extramedular.

A case of extramedullary plasmacytoma of the maxillary sinus, locally aggressive, in a 65 years old man is presented. Clinical diagnosis of adenocarcinoma was suspected but the pathological study showed an anaplastic morphology, with little plasmacytic differentiation and lack of stain with cytokeratins and epithelial membrane antigen (EMA), immunohistochemical marker of plasmatic cells, among others. Definitive diagnosis was based on light chain restriction and lack of multiple myeloma.

[Primary round-cell liposarcoma of the bladder]. / Liposarcoma de células redondas primario de vejiga urinaria.

OBJECTIVE: To report a rare case of primary round cell liposarcoma of the urinary bladder. METHODS: A case of primary round cell liposarcoma of the urinary bladder in an 80-year-old female with hematuria is presented. The patient had a large, solid, non-circumscribed bladder tumor of 6.5 cms. The radiological, histological and immunohistochemical findings are discussed. RESULTS: The neoplasm was composed of isolated lipoblasts among numerous small round cells that were positive for S-100 and vimentin, and a high proliferation rate was demonstrated by Ki-67. The patient died 10 months after the histologic diagnosis. CONCLUSION: Primary liposarcoma of the urinary bladder is a very rare tumor with a poor prognosis that usually presents as a large tumor mass.

[Cytological diagnosis of malignant melanoma of the esophagus]. / Diagnóstico citológico de melanoma maligno de esófago.

Malignant melanoma of the esophagus is an extremely rare neoplasm. We presented a case of this neoplasm diagnosed on a cytologic smear from a 84 year-old women. The smear was characterized by scattered dissociated cells with hyperchromatic irregular nuclei, prominent nucleoli and occasional cytoplasmic brown pigment. The immunohistochemical study revealed positivity for HMB-45 and S-100 protein.

Lymph node response and its relationship to prognosis in carcinomas of the head and neck.

The lymph nodes of 32 patients operated on for carcinomas of the larynx and pharynx, were evaluated for the pattern of lymph node response. Pattern 1 (predominantly lymphocytes) and pattern 2 (predominantly germinal centres) showed a fewer number of nodal metastases than pattern 3 (non-stimulated nodes). Well-differentiated carcinomas predominated in patterns 1 and 2, whereas moderately and poorly differentiated predominated in pattern 3. Patterns 1 and 2 predominated in clinical stages I-III, and pattern 3 in stage IV. The survival decreased progressively from pattern 1 to pattern 3.