Recurrent malignant solitary fibrous tumor of the scalp: a case report and literature review

Prolonged generalized osteomalacia associated with a sinonasal cavity phosphaturic mesenchymal tumor: A case report

Phosphaturic mesenchymal tumor (PMT) is a rare disorder primarily affecting the extremities. It is notable for its correlation with hypophosphatemic osteomalacia and high FGF23 serum levels, which results in renal phosphate wasting and clinical symptoms associated with low serum phosphorus. We presented a patient with a 5-year history of progressive osteomalacia who recently experienced a major pathological bone fracture. Laboratory findings showed a persistent low serum phosphate, normal calcium, elevated alkaline phosphatase activity, high parathyroid hormone levels, and increased renal excretion of phosphate. According to ultrasonography and nuclear imaging, there was no evidence of parathyroid adenoma. During further diagnostic assessment, a sinonasal cavity tumor was found and resected. Histologically, the tumor was composed of bland spindle cell proliferation in the background of a calcified matrix with foci of osteoid formation, hemangiopericytoma-like (HPC-like) vasculature, and osteoclast-like giant cells. Tumor cells showed variable positivity for SMA, but CD34, S100, CD99, Melan-A, p63, and desmin were all nonreactive. Regarding the clinical context, histological and immunohistological findings, a final diagnosis of tumor-induced osteomalacia (TIO) secondary to a PMT was made. After surgery, laboratory results returned to normal, clinical symptoms disappeared, and the patient did not experience a recurrence during a six-month follow-up.

Adrenal Solitary Fibrous Tumor: A Case Report

Solitary fibrous tumor is a mesenchymal neoplasm that first appeared in the literature as a pleural lesion, but over the last decades, it has been reported in many extrathoracic sites. Primary solitary fibrous tumor in the adrenal gland is very uncommon. Its biological behavior is variable but mostly benign. We report here a case of an apparently healthy woman who, in the context of the study of limb paresthesias, was diagnosed with an adrenal incidentaloma. Laboratory tests were performed, and no hormone hyperfunction was detected. Subsequently, a right adrenalectomy was performed, and the pathological study confirmed a solitary fibrous tumor. To the best of our knowledge, this is the 19th case reported in the literature of a primary solitary fibrous tumor originating from the adrenal gland and, notably, the first documented instance in Spain.

Favorable outcome of a histiocytic sarcoma patient treated with immune checkpoint inhibitor: a case report

Introduction and Importance

Histiocytic sarcoma (HS) is an extremely rare malignancy in which there has been no standard treatment approach. Some preclinical studies have provided rationales for the application of immunotherapy in advanced HS.

Case Presentation

The authors reported a case of a 61-year-old patient with metastatic HS who had a rapid progression on ifosfamide, carboplatin, and etoposide chemotherapy. The authors performed PD-L1 testing, which showed a strong positivity in 90% of tumor cells. The patient was then treated with pembrolizumab 200 mg every 3 weeks. He refused palliative radiotherapy. A dramatic response in all sites was recorded on the PET-CT scan after three cycles. He was maintained on pembrolizumab, reaching over 30 months without disease progression.

Clinical Discussion

Recent molecular data suggests there could be a role of immunotherapy in HS. In our patient, the disease was refractory to chemotherapy and pembrolizumab has been given based on the strong PD-L1 expression. Response to immunotherapy has also been recorded in several cases with malignant histiocytic neoplasm.

Conclusion

Immunotherapy might bring sustained disease remission in PD-L1 high expression HS and further studies evaluating the role of immune checkpoint inhibitor in this disease are warranted.

Primary sclerosing liposarcoma of the ovary: Case report and a review of the literature

INTRODUCTION

Primary soft tissue sarcoma of the ovary is uncommon, with most literature reports being in the format of a single case report or small case series.

PRESENTATION OF CASE

We report a case of a primary sclerosing liposarcoma of the ovary in a 67-year-old lady. She presented with a rapidly growing ovarian mass, which was surgically excised. Histologically, the lesion appeared nodular with alternating hypercellular and low-cellularity areas, with areas of necrosis. It comprised atypical spindled, oval and stellate cells set in abundant myxoid and fibrous hyalinised stroma. Immunohistochemistry showed expression of p16, CDK4, CD34, S-100 and MDM2. The case was sent to a referral centre where MDM2 gene amplification was detected by interphase fluorescent in-situ hybridisation (FISH) analysis, rendering a diagnosis of well-differentiated sclerosing liposarcoma with focal low-grade dedifferentiation.

DISCUSSION

To the best of our knowledge, this is the first reported example of a sclerosing variant of liposarcoma in the ovary. Differential diagnosis includes microcystic stromal tumour (MST), sclerosing stromal tumour (SST), atypical spindle cell lipoma, myxoid liposarcoma, myxofibosarcoma, solitary fibrous tumour and low grade fibromyxoid sarcoma.

CONCLUSION

Ovarian sarcomas are characterised by a rapid and aggressive clinical course, requiring multidisciplinary team input for ongoing management. Complete surgical resection with clear margins is the mainstay of treatment.