Role of fine needle aspiration cytology in the diagnosis of soft tissue tumours and tumour-like lesions

In this study, we evaluated the usefulness of fine needle aspiration cytology (FNAC) in the diagnosis of soft tissue tumours. We have also assessed the various pitfalls of FNAC of soft tissue tumours. This was a retrospective study and here we analysed only 82 histopathology proven cases of FNAC of soft tissue tumours diagnosed in a five and half year period. On histopathological examination, 55 of these cases were malignant and 27 were benign. There was a total of 15 recurrences and histopathology was available prior to FNAC in only eight of these cases. Therefore, excluding these eight cases, malignant tumours were primarily diagnosed by FNAC in 47 cases. The sensitivity, specificity and positive predictive value of FNAC in diagnosis of soft tissue tumours were 91.5%, 92.5% and 95.5%, respectively. Only 22 of 47 cases (46.8%) were correctly categorized. There were two false-positive and four false-negative cases. One case each of fibromatosis and schwannoma were reported as sarcoma. False-negative cases were fibrosarcoma (1), malignant nerve sheath tumour (2) and haemangiopericytoma (1). FNAC was very useful in distinguishing benign from malignant soft tissue tumours. However, it was not so effective in exact categorization of tumours.     

Role of fine needle aspiration cytology in the diagnosis of soft tissue tumours

Fine needle aspiration cytology (FNAC) is a widely accepted safe, simple and rapid diagnostic procedure used in the examination of neoplastic and non‐neoplastic lesions of various locations. Since its introduction, FNAC has developed into an effective diagnostic tool practiced in a large majority of medical centres evaluating and treating oncological patients. The role of FNAC has been limited in the examination of primary soft tissue lesions, however, as many physicians working in this area recommended against using FNAC. An increasing use of minimally invasive diagnostic procedures in the last decade has resulted in a better acceptance of FNAC as a first‐line approach or as a complementary tool to core needle biopsy in the diagnosis of musculoskeletal lesions. This review discusses the role and value of FNAC in the evaluation and treatment of soft tissue tumours based on the experience gathered over the course of 48 years at the Sarcoma Center in Lund, Sweden. FNAC reports most often provide diagnostic information allowing the initiation of treatment or, when definitive diagnosis cannot be rendered from a cytological examination, guiding the continued diagnostic investigation. The main advantages of soft tissue FNAC are good sensitivity and specificity, low morbidity, speed of diagnosis, and low cost/benefit ratio. The most important disadvantages stem from limited experience in cytological diagnosis of soft tissue tumours and a lack of standardised and uniform reporting system for soft tissue FNAC.     

Endoscopic ultrasound-guided fine needle aspiration cytology of pancreatic neuroendocrine tumours: cytomorphological and immunocytochemical evaluation

OBJECTIVES: Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) is increasingly used in preoperative localization and diagnosis of pancreatic neoplasms including neuroendocrine tumours (NETs). The objective of the present study was to identify the cytological features of pancreatic NETs obtained by EUS-FNA. METHODS: The study group consisted of nine cases of pancreatic tumours correctly diagnosed or strongly suggestive of NETs based on EUS-FNA. Cytological smears were retrospectively reviewed. The clinical data and immunocytochemical stains applied to the cell block preparations were also reviewed and examined. RESULTS: All cases except one showed characteristic cytomorphological features sufficient for their recognition and separation from pancreatic adenocarcinoma and other lesions. The most helpful cytological features that facilitated the cytological diagnosis of NET were a richly cellular aspirate with a monotonous, poorly cohesive population of small cells with a speckled or dusty chromatin pattern and plasmacytoid morphology. The neuroendocrine differentiation of these tumours was further confirmed by immunocytochemistry. CONCLUSION: EUS-FNA is a valuable method in the recognition of pancreatic NETs. By adherence to the characteristic cytomorphological criteria of pancreatic NET together with collection of suitable material for ancillary immunocytochemical stains, cytopathologists could reach a correct diagnosis in most instances.     

Mediastinal masses diagnosed as thymus hyperplasia by fine needle aspiration cytology

OBJECTIVE: Thymic hyperplasia in the anterior mediastinum can occur in healthy children as idiopathic thymic hyperplasia or as a rebound effect after administration of chemotherapy in patients with malignancies. Thymic hyperplasia after chemotherapy is a well-documented phenomenon, particularly in children and less frequently in adults. Both forms of thymic hyperplasia are a diagnostic challenge, and most patients undergo surgical exploration. Fine needle aspiration cytology (FNAC) has supposed to be inadequate to diagnose benign thymic hyperplasia and to separate it from malignant disease. STUDY DESIGN: We report the cytologic findings on eight patients presenting with a mass in the anterior mediastinum that was diagnosed as thymic hyperplasia on FNAC. In five patients the masses developed after chemotherapy. The remaining three patients were healthy children. Three patients underwent ultrasound-guided aspiration; in five cases the procedure was performed under computerized guidance. RESULTS: In all eight patients the cytologic smears showed a mixed population of lymphoid cells. Cytologic diagnosis of thymic hyperplasia was confirmed by immunophenotyping in three patients and by follow-up studies in all of them (median, 68 months; range, 8-113). CONCLUSION: In contrast to previous reports, this study demonstrated the utility of FNAC as a front-line investigative procedure in diagnosing thymic hyperplasia.     

Intraabdominal desmoplastic small round cell tumor. Report of a case diagnosed by fine needle aspiration cytology.

In this report, fine needle aspiration (FNA) findings in a case of intraabdominal desmoplastic small round cell tumor (IADSRCT) are presented. Computed tomographic scan-guided FNA performed on a right upper abdominal mass on a 20-year-old man produced a cellular specimen consisting of monomorphic small round cells with scant cytoplasm and ovoid nuclei. FNA cytology and immunocytochemistry suggested the diagnosis of IADSRCT. Surgical removal of the tumor and detailed histology and ultrastructural studies confirmed the cytologic findings.     

Carcinoid tumour of male breast diagnosed by fine needle aspiration

A primary carcinoid tumour of the breast in a 66-year-old man was diagnosed by fine-needle aspiration cytology. The nature of the lesion was proved by histochemical and immunocytochemical studies. The importance of a conclusive diagnosis is discussed and the value of immunocytochemical analysis as an aid to cytomorphologic diagnosis is demonstrated.     

Difficulties in diagnosing small round cell tumours of childhood from fine needle aspiration cytology samples

There are four basic reasons for the difficulties in diagnosing small round cell tumours (SRCT) in childhood from fine needle aspiration cytology (FNAC) samples. First, SRCTs are rare and it is difficult for cytopathologists to obtain enough experience for rendering reliable diagnoses. Second, SRCTs are morphologically very similar. Third, many SRCTs do not have specific antigens which could be demonstrated with immunocytochemistry (ICC) or they lose them when poorly differentiated. In addition, cross reactivity exists between some SRCTs. Unstandardized performance of ICC also contributes to the difficulties due to unreliable results. Fourth, suboptimal FNAC samples add additional pitfalls. The latter may be due to partly degenerate samples or to unrepresentative ones in cases where a SRCT is a heterologous component of another nosological entity. Lymphoma, neuroblastoma, nephroblastoma, Ewing's tumour/primitive neuroendocrine tumours and rhabdomyosarcoma are discussed in detail, while other less common SRCTs are mentioned as differential diagnoses when appropriate. The use of cytogenetic and molecular techniques for differentiating between certain SRCTs is helpful in some doubtful cases. However, there are still problems in the use of these techniques, especially their cost which may delay their being introduced in every cytopathology laboratory.