The minimum volume of pleural fluid required to diagnose malignant pleural effusion: A retrospective study.

BACKGROUND: Pleural fluid cytology is a quick and accurate method to diagnose malignant pleural effusions. The optimal volume of fluid for cytological analysis has not yet been identified, and clinical recommendation based on some published clinical experiences has been to send large volumes of fluid for cytological analysis. A quality improvement initiative at our institution was conducted to determine the volume of fluid sufficient for a diagnosis of malignant pleural effusion. MATERIALS AND METHODS: The study was approved by the Institutional Review Board. All pleural fluid specimens that were divided into three volumes (25 mL, 50 mL, and 150 mL) and sent for cytological examination were reviewed. RESULTS: A total of 74 samples from 60 individual patients were evaluable. Thirty-six patients (60%) had a previous diagnosis of malignancy. Of the 74 specimens, 26 (35.1%) were positive for malignancy. The detection rate for malignant pleural effusion by cytology for 25 mL, 50 mL, and 150 mL were 88.5%, 96.2%, and 100.0%, respectively (P = 0.16). Two specimens that were negative in the 25 mL samples turned out to be positive in the 50 mL and 150 mL samples. One specimen was negative in the 25 mL and 50 mL samples but positive in the 150 mL sample. CONCLUSIONS: Our study did not show any statistically significant difference in the detection of malignant effusion in the 25 mL, 50 mL, and 150 mL group.

Solitary fibrous tumor of nasal cavity in patient with long-standing history of cocaine inhalation.

We report a solitary fibrous tumor in the nasal cavity of a 48-year-old woman who presented with a history of bilateral nasal obstruction and long-standing cocaine inhalation. Physical examination revealed a large mass involving the right nasal cavity and extending into the posterior aspect of the left nasal cavity. The computed tomography scan showed opacification of airways. During surgery, the mass was found to involve the entire nasal cavity, with extension to the right maxillary sinus, posterior nasal airways, and left nasal cavity. The mass was completely excised. Pathologic examination revealed a polypoid mass 3.7 x 3.0 x 1.2 cm. This tumor was composed of spindle cells that were cytologically bland in a background of ropey and nodular collagen, giving a "patternless" pattern. Immunohistochemically, the neoplastic cells stained for CD34 and vimentin but not for S100 protein, keratin, desmin, HMB-45, and c-Kit. This immunohistochemical pattern confirmed the diagnosis of solitary fibrous tumor. Although solitary fibrous tumors are usually found in the pleura, they can occur in various other locations, such as the orbit, nasal cavity, paranasal sinuses, mediastinum, breast, vagina, meninges, and soft tissues. This case is of interest because the tumor occurred in a patient with prolonged cocaine inhalation. Such an association has not been previously described. The exact causal relationship between cocaine inhalation and the tumor is not known.

Clinicopathological analysis of c-kit expression in carcinosarcomas and leiomyosarcomas of the uterine corpus.

OBJECTIVE: The purpose of this study was to evaluate the expression of the protooncogene, c-kit, in carcinosarcomas and leiomyosarcomas of the uterine corpus and determine the associations between c-kit expression and clinicopathologic factors, including clinical outcome. METHODS AND MATERIALS: Using a polyclonal anti-KIT-antibody, immunohistochemical staining was performed on formalin-fixed paraffin-embedded tissue blocks from 21 carcinosarcomas, 17 leiomyosarcomas, and 1 endometrial stromal sarcoma. KIT-positive tumors were defined as those tumors demonstrating immunopositivity in > or =30% of tumor cells examined. KIT-negative lesions demonstrated immunopositivity in <30% of tumor cells. Two authors independently scored the slides as positive or negative. Staining was repeated on all specimens and independently scored, and in the occasion of a mismatch, a third staining was performed. The carcinosarcomas were catalogued as to whether the sarcomatous and/or carcinomatous elements expressed c-kit. Clinical data were abstracted for those patients with uterine carcinosarcomas. The associations between clinicopathologic characteristics and c-kit expression were compared using univariate and multivariate analyses. Kaplan-Meier curves based on c-kit expression were plotted for progression-free and overall survival and compared using the log-rank test. RESULTS: Nine of 21 (43%) carcinosarcomas demonstrated immunopositivity for the KIT receptor, although staining was relatively weak. In contrast, only 1/17 (6%) leiomyosarcomas demonstrated KIT immunopositivity (P = 0.029). The solitary endometrial stromal sarcoma evaluated did not demonstrate significant KIT positivity. The majority of KIT-positive carcinosarcomas (6/9 (67%)) demonstrated KIT presence in the sarcomatous portion as compared to the carcinomatous portion (4/9 (44%)). No clinical factor had a statistically significant association with c-kit expression. The lack of c-kit expression was the only factor that was significantly associated with disease recurrence in univariate and multivariate analyses (P < 0.05), although there appeared to be a trend toward a low stage associated with kit positivity. The median progression-free interval for the KIT-negative cohort was 8 months, while it had not been reached for the KIT-positive cohort after median follow-up of 15 months (P = 0.0462). CONCLUSIONS: A significant proportion of carcinosarcomas of the uterine corpus display immunoreactivity for c-kit. Patients with KIT-positive carcinosarcomas may have an improved progression-free survival compared to KIT-negative tumors; however, further data are needed to determine whether this finding is confounded by stage.

Evaluation of the relationship between adenosarcoma and carcinosarcoma and a hypothesis of the histogenesis of uterine sarcomas.

The terminology of uterine sarcomas is confusing and has been inconsistently applied. The relationships among the various types of uterine sarcomas are unknown. To elucidate the relationship between carcinosarcoma (malignant mullerian mixed tumor) and adenosarcoma, a series of 26 consecutive endometrial carcinosarcomas was evaluated for the presence of an adenosarcoma-like component. Four of 26 carcinosarcomas (15%) had an adenosarcoma-like component. The clinical and pathologic features of these tumors were otherwise similar to ordinary endometrial carcinosarcomas. A histogenetic schema for uterine sarcomas is proposed, interrelating endometrial stromal sarcomas, adenosarcomas with and without sarcomatous overgrowth, and poorly differentiated sarcoma not otherwise specified. Although most carcinosarcomas are accepted as being metaplastic or sarcomatoid carcinomas, it is suggested that the carcinomatous component of 8% to 16% of carcinosarcomas arise within, or in the endometrium adjacent to, an adenosarcoma. This latter group is then integrated into the histogenetic schema. Observations based on our data and the limited data in the literature that support this hypothesis include: 13% of endometrial carcinosarcomas have gross and microscopic features of collision tumors, 13% have an adenosarcoma-like component, 16% have a low-grade stroma, and approximately 8% are biclonal indicative of a collision tumor. The most parsimonious interpretation of these data indicates that approximately 8% to 16% of endometrial carcinosarcomas arise because of malignant transformation of the epithelial component within, or in the endometrium adjacent to an adenosarcoma.