Clear cell sarcoma of the soft parts arising in the rectus abdominis in a child - aspiration cytology of a rare case

Abstract

Background: Clear cell sarcoma of soft parts is most commonly found associated with the tendons and aponeuroses of distal extremities in young adults with a peak incidence in the third decade. Location in the abdominal wall and in a child is very rare.

Case presentation: A nine-year-old female child presented with a swelling in the anterior abdominal wall in the suprapubic region. Fine needle aspiration revealed predominantly discrete cells with loose clustering at places. The cytoplasm was abundant, finely granular, and eosinophilic with some cells exhibiting clear vacuolated zones. No pigment was seen. The nuclei were rounded and eccentrically placed with a striking single eosinophilic macro nucleolus present in all the cells. Taking into consideration, the history, age of the patient, location of the tumor and absence of melanin pigment, a diagnosis of soft tissue sarcoma was made, the differential including Clear cell sarcoma. This was subsequently confirmed on histopathological examination and immunohistochemistry

Conclusion: The atypical presentation of the case made the cytological diagnosis rather challenging. Clear cell sarcoma should be considered when cytology of a soft-tissue tumor shows uncharacteristically high cellularity and relatively uniform cells with macronucleoli.

Figure 1

Moderate to highly cellular smear with predominantly discrete cells. Loose clusters are also seen. The background is relatively clean. Papanicolaou stain × 200.

Figure 2

Loose cluster of epithelioid cells with abundant granular cytoplasm, rounded nuclei with mild to moderate anisokaryosis and prominent eosinophilic macro nucleolus. Note the micro acinus like formation in the centre. Papanicolaou stain × 1000.

Figure 3

Discrete cells showing abundant granular cytoplasm with vacuolation. Papanicolaou stain × 1000.

Figure 4

Thin fibrous septa dividing cells arranged in a nesting/alveolar pattern with prominent nucleolus and clear cytoplasm. Hematoxylin and Eosin × 400.

Figure 5

Immunohistochemistry with HMB 45 showed the tumor cells exhibiting cytoplasmic positivity. IHC – Streptavidin Biotin × 200.

Figure 6

The tumor cells expressed a strong positivity for Neuron specific Enolase (NSE). IHC – Streptavidin Biotin × 400.

Figure 7

The tumor cells also were positive for S100. IHC – Streptavidin Biotin × 400.