Intracranial solitary fibrous tumour with rhabdomyosarcomatous differentiation: A diagnostic challenge of a rare presentation.

INTRODUCTION AND IMPORTANCE

Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms, initially described in the pleura but capable of arising in various anatomical locations, including the central nervous system. Dedifferentiation, characterized by the transformation of a low-grade tumor into a high-grade sarcoma, is an uncommon phenomenon in SFTs, especially in the intracranial region.

CASE PRESENTATION

A 31-year-old male visited the neurology outpatient department with complaints of frequent headaches, seizures, speech difficulties, and weakness on the left side of his body. MRI was done which showed a relatively well defined T1 isointense and T2 hypointense extra-axial mass lesion in the right frontal lobe. Histopathological analysis confirmed the diagnosis of dedifferentiated SFT, marked by distinct fibroblastic differentiation and areas of high-grade sarcomatous transformation (rhabdomyosarcoma). Immunohistochemically, areas with fibroblastic differentiation showed strong and diffuse positivity for CD99, STAT6, vimentin and focal BCL-2 High-grade sarcomatous area was positive for vimentin, desmin and Myo-D1 and was negative for GFAP, EMA, PR, S-100, SMA and CD-34. It also showed focal positivity for STAT-6. The final diagnosis of intracranial solitary fibrous tumor with rhabdomyosarcomatous differentiation was made. At 2 months of follow-up, the patient is doing well.

CLINICAL DISCUSSION

Given the rarity of dedifferentiation in intracranial SFTs, there is limited consensus on optimal management strategies. En bloc resection remains the primary treatment approach, though the unpredictable behaviour of dedifferentiated SFTs complicates prognosis. This case underscores the importance of integrating clinical, radiological, and pathological findings for accurate diagnosis and discusses the need for further research into effective therapeutic options for dedifferentiated SFTs, particularly in challenging intracranial cases.

CONCLUSION

This case report presents a unique instance of an intracranial dedifferentiated SFT with rhabdomyosarcomatous dedifferentiation, highlighting the significant diagnostic challenges posed by this rare entity.