Thymolipoma in child: a case diagnosed by correlation of ultrasound-guided fine needle aspiration (EUS-FNA) cytology and computed tomography with histological confirmation

The Utility of Fine Needle Aspiration (FNA) Biopsy in the Diagnosis of Mediastinal Lesions

Fine needle aspiration is a minimally invasive, low-morbidity, and cost-efficient technique for the sampling of mediastinal lesions. Additionally, ancillary testing on FNA samples can be used for the refinement of diagnoses and for treatment-related purposes (flow cytometry, cytogenetics, immunohistochemistry, and molecular diagnostics). Mediastinal lesions, however, can show a variety of lineages and morphologic features, giving rise to diagnostic dilemmas. As a result, the differential diagnosis can vary widely and becomes especially challenging due to the smaller sample size on FNA and the variability in component sampling. For appropriate patient management and to determine the correct treatment strategies, accurate pathologic diagnoses are paramount. In this review, we present the cytomorphologic features together with the immunophenotypic findings of mediastinal lesions, with emphasis on the diagnostic challenges and pitfalls in FNA cytology samples, including smears and cell block sections.

How to obtain adequate biopsy specımen in suspected thymic tumors

Pathologic diagnosis of thymic tumors (TTs) can be made by surgical or nonsurgical procedures. About 20% of TTs had been diagnosed by pretreatment biopsy methods while the rest had gone to surgery for diagnosis and treatment. However, in the last two decades there was an increase in pretreatment procedures for optimal management of locally advanced or metastatic TTs. Pretreatment tissue diagnosis of a noninvasive TT is not a standard option but is required if there is suspect or atypical clinical presentation and imaging, an invasive tumor requiring a nonsurgical approach or preoperative chemotherapy or chemo-radiotherapy, strong possibility of lymphoma or unclear differential diagnosis between lymphoma or other solid tumor by imaging studies, or suspicion of a metastatic lesion. In surgical diagnosis anterior mediastinotomy, video-assisted thoracic surgery or mediastinoscopy can be chosen for invasive TTs whereas total resection is performed for small, noninvasive tumors. Nonsurgical diagnosis can be made by transthoracic fine or core needle biopsies (TTFNA, TTCNB), conventional bronchoscopy, endobronchial ultrasonography-guided transbronchial needle aspiration (EBUS-TBNA), endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) or medical thoracoscopy depending on procedural amenability according to tumor extension. TTFNA and TTCNB have been the most frequently used nonsurgical methods. However, there is an upward trend in using conventional bronchoscopy, EBUS-TBNA, EUS-FNA and medical thoracoscopy recently. To increase the diagnostic performance of these procedures in TTs, recommendations are (I) obtaining histologic specimens, (II) combining smears or liquid based cytology preparations and cell blocks, (III) obtaining multiple sufficient samples, (IV) combining histologic and cytologic specimens, (V) performing morphologic, immunohistochemical and molecular analyses on all specimens, (VI) using rapid onsite evaluation for cytologic specimens, (VII) correlating pathologic, clinical and radiologic findings, (VIII) consulting experienced pathologists.

Pediatric fine-needle aspiration cytology: An audit of 266 cases of pediatric tumors with cytologic-histologic correlation

Objectives:

Fine-needle aspiration cytology (FNAC), a well-accepted minimally invasive diagnostic technique utilized in adults, is gradually gaining ground for pediatric patients as well. However, there are very few comprehensive reports in the literature on utility of FNA in pre-operative diagnosis of pediatric tumors.

Material and Methods:

An observational study was conducted at a cancer research center and a pediatric tertiary care hospital over a 5-year period. A cytologic-histologic correlation was performed for FNACs performed in pediatric patients for a clinical diagnosis of neoplastic lesions at both the centers. Relevant clinical details and histopathology, wherever available, were retrieved. Sensitivity, specificity, and accuracy of FNAC in diagnosis of malignant lesion were calculated from the cases with available histologic correlation.

Results:

Of the 266 cases included, there was a slight male predominance with lymphadenopathy being the most common presentation and non-Hodgkin’s lymphoma as the most frequent diagnosis in cases clinically suspected to have a neoplasm. Histologic correlation was available in 112 cases with 100% concordance in liver and kidney tumors. Few rare cytologic diagnoses such as papillary renal cell carcinoma, mesenchymal hamartoma of the liver, and thymolipoma could be accurately rendered on FNAC smears in conjunction with the clinic-radiologic features. The sensitivity, specificity, and accuracy of FNA in diagnosing malignant pediatric tumors were found to be 100%, 92.6%, and 97.7%, respectively.

Conclusion:

The present study underscores the high sensitivity and accuracy of FNAC in diagnosis of pediatric tumors, both in superficial and deep-seated locations. Awareness of the cytomorphologic features and clinic-radiologic correlation may assist the cytopathologists in rendering a precise diagnosis of rare pediatric tumors as well.

Giant thymolipoma of mediastinum and neck - initially misdiagnosed as liposarcoma by core needle biopsy

Thymolipomas are rare benign tumors, constituting one of the differential diagnoses of an anterior mediastinal mass. These tumors may have an indolent, asymptomatic course, often achieving massive dimensions before presentation. When it is symptomatic, respiratory symptoms predominate. We report a case of thymolipoma in a 30-year-old male complaining of heaviness and constricting type of chest pain and neck swelling of 1-year duration. Computed tomography scan finding revealed a space-occupying lesion in the anterior mediastinum and extend to the right side of the mediastinum, neck, and left hemithorax. A sono-guided core needle biopsy was carried out which identified an atypical cell and was suspicious to liposarcoma. The tumor was completely excised through “posterolateral thoracotomy.” Postoperative histopathological examination confirmed the diagnosis of thymolipoma. This is the second case we have reported from our institution.

Persistent radiologic thoracic hypotransparency: A case report and review of the literature

A thymolipoma is a slow-growing, anterior mediastinal tumor, rare in childhood. The authors present a report of a 4-year-old girl with persistent right thoracic hypotransparency on the chest radiograph. Computed tomography and magnetic resonance imaging revealed an anterior, well-limited, mediastinal mass of heterogeneous density, with lipomatous and soft tissue density areas. The tumor was totally excised and the histopathologic findings revealed a thymolipoma. A year and a half after surgery, the child remains well. This report enhances the relevance of differential diagnosis in the presence of persistent radiologic thoracic hypotransparency.