Serous effusions are a common complication of lymphomas. Although the frequency of pleural effusion is 20-30% in non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD), the involvement of peritoneal and pericardial cavities is uncommon. Among lymphoma subtypes, T-cell neoplasms, especially the lymphoblastic lymphomas, more frequently involve the serous fluids. The thoracic duct obstruction and impaired lymphatic drainage appear to be the primary mechanism for pathogenesis of pleural effusion in HD and direct pleural infiltration is the predominant cause in NHL. There is wide variation in rate of positive cytologic findings of NHL in pleural effusion (22.2-94.1%). Cytologic features of specific lymphoma subtypes such as lymphoblastic lymphoma, follicular center cell lymphoma, including Burkitt-type lymphoma, marginal zone lymphoma, MALT lymphoma, and anaplastic large-cell lymphoma, etc., have been described in the literature. The differential diagnostic problems of lymphomas in serous effusions include reactive lymphocytoses, early involvement by lymphomatous process, small round-cell tumors (SRCT), and presence of look-alike of Reed-Sternberg cells. To overcome these difficulties, various ancillary studies, including immunocytochemistry (ICC), morphometry, flow cytometry (FCM), and cytogenetics/molecular genetics (PCR, in-situ hybridization, and Southern blotting), have been performed on effusion specimens. ICC not only distinguishes lymphomas from reactive lymphocytoses and SRCTs, it significantly modifies the morphologic diagnosis to achieve a better classification of lymphomas. Combined morphology and immunophenotyping by FCM, has a sensitivity as well as specificity of 100%. Morphometry also distinguishes reactive lymphocytoses from malignant lymphoma with a high degree of sensitivity (>85%) and specificity (>95%). Limitations of individual ancillary techniques can be overcome by using multiple parameters. Although lymphomas rarely present as serous effusions without the involvement of other thoracic and extrathoracic sites, a small group of lymphomas called primary effusion lymphomas (PEL) exhibit exclusive or dominant involvement of serous cavities, without a detectable solid tumor mass. This body cavity based lymphoma (BCBL) is a distinct clinicopathologic entity and is found predominantly in AIDS patients with preexisting Kaposi sarcoma. In the absence of obstructive or infiltrative tumor mass, its pathogenesis has been attributed to stimulation by vascular endothelial growth factor (VEGF)/vascular permeability factor (VPF), leading to vascular leakage. Cytomorphologically, PEL is usually a large-cell lymphoma, which appears to bridge features of large-cell immunoblastic and anaplastic large-cell lymphoma (ALCL). Most of these cases comprise a unique subgroup of B-cell lymphoma, with features of both high-grade anaplastic and B-immunoblastic lymphoma, but T-cell and/or natural killer cell immunophenotypes are described. Its association with various viral DNAs has been studied in detail by molecular techn...

Psammoma bodies (PBs) are concentric lamellated calcified structures, observed most commonly in papillary thyroid carcinoma (PTC), meningioma, and papillary serous cystadenocarcinoma of ovary but have rarely been reported in other neoplasms and nonneoplastic lesions. PBs are said to represent a process of dystrophic calcification. Despite numerous ancillary studies over a span of three and half decades, formation of PBs remains a poorly understood mechanism. Ultrastructural study of PTC has shown that thickening of the base lamina in vascular stalk of neoplastic papillae followed by thrombosis, calcification, and tumor cell necrosis leads to formation of PBs. Studies on serous cystadenocarcinoma of ovary and meningioma, however, revealed that collagen production by neoplastic cells and subsequent calcification was responsible for the formation of PBs. The existence of some precursor forms of PBs was reported in meningiomas and more recently in PTC, which were mostly in the form of extracellular hyaline globules surrounded by well-preserved neoplastic cells or in a smaller number of cases intracytoplasmic bodies liberated from intact tumor cells. Cellular degeneration and necrosis, leading to the disappearance of neoplastic cells, were noticed by us only around PBs but not around the precursor forms. Based on the above findings, it is suggested that rather than being the outcome of dystrophic calcification of dead or dying tissue, PBs may indeed represent an active biologic process ultimately leading to degeneration/death of tumor cells and retardation of growth of the neoplasm. It may also serve as a barrier against the spread of neoplasm.

Introduction: A mass in the salivary gland region often presents a diagnostic challenge with regard to its site of origin (salivary versus nonsalivary), benign or malignant nature, and tissue-specific diagnosis. The present study describes the utility of fine-needle aspiration (FNA) cytology in the diagnosis of these lesions. Subjects and Methods: Over a 6-year period (January 1994 to December 1999), 712 patients aged between 6 months and 91 years (median, 37 years) were subjected to FNA of swellings in their salivary gland regions. Male:female ratio was 1.28:1. The swellings were mostly located in the parotid (323 cases), submandibular (343 cases), and upper cervical region (27 cases). Swellings of oral (5 cases) and sublingual (2 cases) sites were rare. The lesions diagnosed by FNA cytology were compared among the major salivary glands. Cytologic diagnoses were correlated with histology in 45 cases. Results: Benign nonneoplastic lesions were the most common (73%), followed by neoplasms (20%), and those with atypical cytology (1%). Cytologic material was inadequate in 6% cases. Parotid gland region was involved more frequently by neoplasms (27.1%) than the submandibular gland region (13.7%, p < 0.0001). Inflammatory processes affected the submandibular gland region more commonly (42.0%) than the parotid (32.6%, p = 0.0164). Pleomorphic adenoma was the most common neoplasm (61.5%), followed by Warthin’s tumor (12.6%). Malignancies accounted for 10.5% of neoplasms. Frequency of involvement of parotid by Warthin’s tumor (16.7%) was significantly higher than that of submandibular gland (2.3%, p = 0.0191). However, the submandibular gland was more commonly affected by malignancy than the parotid gland (p = 0.0003). Sensitivity, specificity, and diagnostic accuracy of FNA cytology for all neoplastic lesions of the salivary gland were 94.6, 75.0, and 91.1%, respectively. The corresponding figures for malignancies were 60.0, 95.0, and 91.1%, respectively. Conclusion: FNA cytology is very useful for the diagnosis of salivary gland lesions. However, sampling and interpretation errors may occur. The low specificity for the diagnosis of neoplasms as a whole and the poor sensitivity for malignancies found in our study can be attributed to the relatively small number of benign nonneoplastic and malignancy cases with available histopathologic diagnoses.

Endometriotic nodules need to be differentiated from other benign/malignant masses and evaluated for possible malignant transformation. FNAC provides a safe and effective tool for diagnosis thereby obviating the need for other procedures.

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