| Abstract|| |
Myxoid liposarcomas metastatic to lungs and mediastinum are infrequent lung neoplasms. The tumor has an aggressive course and needs to be recognized cytologically. A 60-year-old male smoker presented with gradually progressive left-sided chest pain, cough, and expectoration for the past one month. Chest radiograph and computed tomography of thorax revealed a lung mass in left apical region extending into the posterior mediastinum, which was subjected to ultrasound-guided fine needle aspiration (FNA). Smears showed a cellular tumor with ovoid to spindle shaped tumor cells in a myxoid background having a rich vascular network. The possibility of a myxoid liposarcoma metastatic to lung and mediastinum was suggested and confirmed by histopathology. A previous history of excision of a tumor in the thigh one and half years ago was present. The importance of recognizing the cytological picture by FNA is discussed.
Keywords: Lung; mediastinum; metastasis; myxoid liposarcoma
|How to cite this article:|
Inuganti RV, Bala SG, Bharathi KY. Metastatic myxoid liposarcoma of lung and mediastinum diagnosed by fine needle aspiration. J Cytol 2011;28:33-5
|How to cite this URL:|
Inuganti RV, Bala SG, Bharathi KY. Metastatic myxoid liposarcoma of lung and mediastinum diagnosed by fine needle aspiration. J Cytol [serial online] 2011 [cited 2021 Mar 3];28:33-5. Available from: https://www.jcytol.org/text.asp?2011/28/1/33/76948
| Introduction|| |
Metastatic neoplasms from bone and soft tissues comprise 8.4% of lung tumors. Myxoid liposarcomas metastatic to lung are extremely rare. The tumor has an aggressive clinical course and needs to be recognized cytologically. Fine needle aspiration cytology (FNAC) of a neoplasm in the lung extending into posterior mediastinum was done in a 60-year-old male and revealed cytological picture of a myxoid liposarcoma. This was confirmed histologically and labelled as metastatic due to a previous history of mass excised from thigh. We are reporting this case in view of its rarity.
| Case Report|| |
A 60-year-old male smoker presented with cough, expectoration, and left-sided chest pain for the past one month. Chest radiograph revealed a mass lesion in the left upper lung [Figure 1]. Computed tomography (CT) of thorax revealed a heterogeneously enhancing lesion in the left hemithorax with the involvement of lung and a major portion of posterior mediastinum. Ultrasound-guided FNAC was performed and smears were stained with hematoxylin and eosin (H and E).
Smears were highly cellular with a myxoid background. Cells were ovoid to spindle shaped with relatively uniform nuclei and thin cytoplasm. Focal areas showed a rich capillary network within the myxoid matrix and occasional large atypical cells, both univacuolated and multivacuolated having scalloped nuclei [Figure 2] and [Figure 3]. A differential diagnosis of fibrosarcoma was considered initially but ruled out on recognizing lipoblasts and the rich capillary network. The final diagnosis was given as a myxoid liposarcoma metastatic to lung and posterior mediastinum. Subsequently, the patient underwent a CT-guided biopsy. Histopathological examination showed a multinodular tumor of moderate cellularity with enhanced cellularity at the periphery. The individual tumor cells were seen in a myxoid matrix with a delicate plexiform capillary vascular network and many cells resembled mature adipocytes [Figure 4]. Univacuolar and multivacuolar lipoblasts were seen; some having large atypical nuclei with scalloped margins. The tumor showed immunoreactivity for S100 protein. The previous tumor in the thigh was reviewed and confirmed with immunohistochemical marker S100 as a myxoid liposarcoma. A diagnosis of classic myxoid liposarcoma in lung was given and in view of a previous history of excision of myxoid liposarcoma in the thigh the final diagnosis was signed out as a metastatic myxoid liposarcoma to lung and posterior mediastinum. Magnetic resonance imaging (MRI) revealed secondary deposits in liver also.
|Figure 2: Cellular smears showing a rich capillary network within a myxoid background (H and E, x 100)|
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|Figure 3: Cytological smears with univacuolated and multivacuolated lipoblasts (H and E, x 400)|
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|Figure 4: Histopathology sections showing the delicate plexiform capillary network (H and E, x 100)|
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The patient was advised chemotherapy after surgery in the thigh but was lost to follow-up and came with the mediastinal mass. Chemotherapy was offered after the current resection. Six cycles of chemotherapy were advised and the patient is responding well.
| Discussion|| |
Among patients that develop lung metastases, leiomyosarcoma is the most common histology, followed by malignant fibrous histiocytoma, liposarcoma, and synovial sarcoma.  The opportunity to study the cytology of tumors metastatic to the lungs has been markedly increased by the use of FNAC to sample the pulmonary lesions of metastatic disease. Before the advent of FNAC, such patients would have been subjected to thoracotomy or treated on the basis of radiologic and clinical findings.
In the diagnostic assessment with FNAC of a patient with suspected cancer metastatic to the lung, the case should be approached in the same manner as evaluation of tissue from open biopsy. The patient's clinical history must be reviewed for either documentation or prior suspicion of a preexisting neoplasm. All prior histologic and cytologic specimens should be reviewed and the cellular changes in the FNAC compared with preexisting diagnostic material. In our case, the patient had an excision of mass from thigh, one and a half years ago, diagnosed as a soft tissue sarcoma, with a differential diagnosis of myxoid liposarcoma/malignant fibrous histiocytoma.
In 1986, Kim and associates reported the morphological features of cells aspirated from 17 sarcomas metastatic to the lung and emphasized their cytological features. 
A preoperative diagnosis of a metastatic tumor to lung is difficult by cytological methods; epithelial tumors being relatively easier to diagnose than sarcomas. Cytological features of mesenchymal tumors and malignancy in particular show spindle-shaped cells with fragile cytoplasm, poorly cohesive and form rather flat cellular aggregates, display many single cells, nuclei with fairly granular chromatin, small nucleoli and bizarre multinucleated cells. This contrasts with the three-dimensional cell aggregates and the coarsely granular nuclei of carcinoma. 
The differential diagnosis includes other mesenchymal malignancies like fibrosarcomas, malignant fibrous histiocytomas, and malignant peripheral nerve sheath tumors. However, these tumors do not show the vascular network characteristically seen even in cytological smears nor do they show the classical lipoblasts. Smears from myxoid liposarcomas usually show myxoid background and the matrix stains blue or blue violet in May-Grόnwald-Giemsa and faintly green in Papanicolaou stain. The tumor cells could be round, spindle-shaped, or pleomorphic. 
| Conclusion|| |
This case is reported to highlight the importance of recognizing metastatic myxoid liposarcoma in cytology smears and to differentiate it from other mesenchymal malignancies.
| References|| |
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|2.||Kim K, Naylor B, Han IH. Fine needle aspiration cytology of sarcomas metastatic to the lung. Acta Cytol 1986;30:688-94. |
|3.||Crosby JH, Hoøeg K, Hager B. Transthoracic fine needle aspiration of primary and metastatic sarcomas. Diagn Cytopathol 1985;1:221-7. |
|4.||Choudhuri MK. Cytology of soft tissue tumors: Cytological classification of soft tissue tumors. J Cytol 2008;25:79-80 |
Renuka V Inuganti
Department of Pathology, Guntur Medical College, Guntur, Andhra Pradesh- 522 004
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4]