Recurrent solitary fibrous tumor of the pleura with malignant transformation: a case report

Evolution of Pleural Solitary Fibrous Tumors Causing Severe Hypoglycemia after Exceptionally Long Asymptomatic Periods: Report of Two Surgical Cases

Non-islet cell tumor hypoglycemia (NICTH) is one of the paraneoplastic syndromes manifesting severe hypoglycemia caused by aberrant production of high-molecular-weight insulin-like growth factor 2 (big-IGF2). Two surgical cases of extremely large thoracic solitary fibrous tumors (SFT) with unusual history of NICTH are presented. One case manifested severe hypoglycemia after four years of the first complete surgical resection of the tumor with potential malignant transformation, and the other case showed severe hypoglycemia after ten years of the first detection of the tumor. Meticulous laboratory testing, including serum endocrinological tests and western immunoblotting before and after surgery was performed, and both cases were diagnosed as NICTH. Both patients underwent open thoracic surgery. The patients showed normal glucose and hormone levels immediately after the resection of responsible tumors with elevated blood insulin concentration. SFTs are generally considered benign; however, life-threatening hypoglycemia can happen regardless of treatment. Careful follow-up of the tumor growth is warranted.

Malignant progression of cerebellopontine angle solitary fibrous tumors following radiation: illustrative case

BACKGROUND

Intracranial solitary fibrous tumors (ISFTs) are rare mesenchymal tumors originating in the meninges and constitute a heterogeneous group of clinical and biological behavior. Benign histotypes, such as hemangiopericytomas are now considered as a cellular phenotypic variant of this heterogenous group of rare spindle-cell tumors. IFSTs are poorly recognized and remain a diagnostic challenge due to rarity and resemblance to other brain tumors. Previously, IFSTs were thought to pursue a slow, indolent, and nonaggressive course, however, a growing body of literature based on longer follow-up demonstrates an unpredictable clinical course and an uncertain diagnosis.

OBSERVATIONS

A rare case report of malignant transformation of IFST following radiation therapy is reported. In this case a 60-year-old female who underwent gross total resection of the cerebellopontine angle tumor with histopathology consistent with solitary fibrous tumor followed by salvage stereotactic radiosurgery, presented with another recurrence after 2 years of surgery. The authors performed complete removal of the tumor with pathology now consistent with malignant solitary fibrous tumor. A recent follow-up magnetic resonance imaging did not show any recurrence or residual tumor, and the patient reports a generalized well-being.

LESSONS

This report will help to understand the natural history and unusual clinical behavior of these intracranial tumors.