Distinction of high-grade neuroendocrine carcinoma/small cell carcinoma from conventional urothelial carcinoma of urinary bladder: an immunohistochemical approach.

CONTEXT: High-grade neuroendocrine carcinomas and small cell carcinomas (HGNEC/SmCC) of the urinary bladder are uncommon but aggressive neoplasms. Differentiation of HGNEC/SmCC from high-grade urothelial carcinoma (UC) is based on histomorphologic features, but can be difficult in small biopsies and cases with mixed morphology. OBJECTIVE: We attempt to identify a limited immunohistochemical panel that aids in this distinction. DESIGN: We selected 39 cases of bladder carcinoma with small cell morphology: 7 HGNEC/SmCC, 21 high-grade UC with neuroendocrine-like pattern, and 11 mixed neoplasms. Immunohistochemistry for pan-cytokeratin, synaptophysin, chromogranin, p63, and thyroid transcription factor-1 was performed. RESULTS: Pan-cytokeratin was positive in 6 of 7 cases (86%) of the HGNEC/SmCC group. All 7 tumors were positive for synaptophysin, 6 of them were negative for p63 and chromogranin, and 1 was positive for p63 and chromogranin. All 21 high-grade UC with neuroendocrine-like pattern of growth showed positive staining for pan-cytokeratin, and were all negative for synaptophysin and chromogranin. Sixteen (76%) of high-grade UC were also positive for p63. All 11 mixed tumors were positive for pan-cytokeratin. In 10 of the 11 mixed tumors (91%), synaptophysin was positive in the neuroendocrine differentiated areas and it was negative in the urothelial component. In 2 of the 11 mixed tumors (18%) chromogranin was also positive. Three (27%) of the 11 mixed cases were positive for p63 in the UC foci. Chromogranin was negative in 6 of the pure HGNEC/SmCC and in 8 of the mixed tumors. None of the 39 samples were reactive for thyroid transcription factor-1. CONCLUSIONS: A limited immunohistochemical panel including pan-cytokeratin, synaptophysin, and p63 discriminates HGNEC/SmCC from high-grade UC.

A case of severe thrombotic thrombocytopenic purpura with concomitant Legionella pneumonia: review of pathogenesis and treatment.

Thrombotic thrombocytopenia purpura (TTP) is a severe multisystem disorder characterized by fever, microangiopathic hemolytic anemia, thrombocytopenia, neurologic symptoms, and impaired renal function. Platelet counts are usually diminished, whereas the bone marrow shows a large number of megakaryocytes indicating peripheral destruction and consumption of platelets. Coagulation studies in patients with TTP are normal or slightly elevated, which helps differentiate this entity from disseminated intravascular coagulation. The peripheral smear shows an abundance of schistocytes, reticulocytes, and, at times, nucleated red blood cells. Serum lactate dehydrogenase and indirect bilirubin are elevated as a result of mechanical destruction of red blood cells. Legionella pneumophila has been identified as a relatively common cause of both community-acquired and hospital-acquired pneumonia. An association between Legionella and TTP has only been cited once in the literature. Here we present a case of severe TTP with concurrent Legionella infection. Our patient presented with the classic clinical findings of TTP and an ADAMTS13 level of less than 5% associated with an inhibitor. After a 3-week treatment course with plasma exchange, steroids, and antibiotics, he had complete clinical recovery and his ADAMTS13 level increased to greater than 75%.

P63 differentiates subtypes of nonsmall cell carcinomas of lung in cytologic samples: implications in treatment selection.

BACKGROUND: Bevacizumab in combination with carboplatin and paclitaxel improves overall response and survival in patients with advanced or recurrent nonsmall cell lung carcinoma. However, this drug is not recommended in patients with squamous cell carcinoma or neoplasms with a dominant squamous component. Therefore, identification of squamous cell differentiation has therapeutic implications. In many instances, cytology is the diagnostic tool of choice; however, routine cytomorphology is limited in classification of nonsmall cell carcinomas into squamous and nonsquamous subtypes. The aim of this study was to identify the value of p63 immunocytochemical analysis in this distinction. METHODS: Review of cytology records identified 51 consecutive pulmonary specimens (16 fine needle aspiration samples, 15 washes, 12 brushes, and 8 lavages) with the diagnosis of nonsmall cell lung carcinoma (9 carcinomas with squamous differentiation and 42 carcinomas without squamous differentiation). Histologically, they all proved to be nonsmall cell carcinomas, 26 with squamous differentiation and 25 without squamous differentiation. p63 immunocytochemical stain was performed on archival alcohol-fixed Papanicolaou-stained cytology slides using standard immunocytochemical methods. RESULTS: Twenty-three (88 %) of the 26 histologically proven squamous cell carcinomas were positive for p63 on cytologic smears. By using p63 immunocytochemistry, the authors detected 14 carcinomas with squamous differentiation not identified by cytomorphology. Smears from all histologically proven carcinomas with squamous differentiation were positive for p63. Sensitivity of cytology for the detection of nonsmall cell carcinoma of lung with squamous differentiation increased from 35% to 88% using p63 immunocytochemistry (P = .001; McNemar test). The squamous component in 4 carcinomas was detected only in cytologic and not in corresponding histologic samples when subsequent p63 immunostaining was performed. CONCLUSIONS: The authors concluded that p63 is a useful marker for the detection of nonsmall cell carcinomas of lung with squamous differentiation when used in cytologic pulmonary samples. p63 immunocytochemistry significantly increases the sensitivity for the identification of lung neoplasms with squamous differentiation from 35% to 88% (P = .001). Therefore, p63 immunocytochemistry may be used in pulmonary cytologic samples of nonsmall cell carcinomas to identify squamous differentiation and to improve therapeutic selection of patients with lung cancer.

Correlación anatomoecográfica de la infiltración tumoral perietal en el cáncer de recto / Anatomoechographical correlation of parietal tumoral infiltration in rectal cancer

Entre noviembre del 89 y octubre del 91, se estudiaron 96 pacientes con patología rectal, por ecografía endoluminal. En ese período se evaluaron 63 tumores, con 40 casos que cumplieron con los criterios de inclusión que se publican en este trabajo. Se incluyen los datos de topografía, histología y grado de diferenciación tumoral y las formas macroscópicas de los tumores. Se clasificaron por el grado de invasión parietal los tumores en: lesiones intraparietales y lesiones evadidas. Correlacionándolos con la antomía patológica, se buscó la sensibilidad, especificidad y valores predictivos de la ecografía endorrectal en la valoración de la capa comprometida. Los resultados fueron buenos y se concluye que este método por su eficiencia y su relación costo/beneficio tiene excelentes resultados en el estudio de esta patología