Splenic Kaposi's sarcoma in a human immunodeficiency virus-negative patient: A case report.

BACKGROUND: Kaposi's sarcoma (KS) is a malignancy that usually affects the skin of the lower extremities, and may involve internal organs. It originates from the vascular endothelium. It is well known that the development of KS is associated with human herpes virus 8 (i.e. HHV8) infections. Sporadic KS cases have mainly been found in Africa. Isolated splenic KS in Asia has rarely been reported. We present here a case of KS primarily involving the spleen in a human immunodeficiency virus (HIV)-negative Chinese patient. CASE SUMMARY: A 50-year-old male patient was admitted to hospital due to abdominal distension and discomfort, reduced food intake and weight loss. Medical examination revealed that the patient had moderate anemia, a low platelet count, slight fatty liver and a huge mass in the spleen. Spleen lymphoma was considered. An anti-HIV test was negative. The whole spleen was surgically excised. The final pathological diagnosis was nodular stage spleen KS, and the patient underwent total splenectomy. He recovered well and was discharged from hospital 12 d after surgery. Two weeks later, the patient developed liver metastasis and died within 1 mo after surgery. CONCLUSION: KS is difficult to diagnose and pathological examination is necessary. KS has a poor prognosis and should be diagnosed and treated early to improve survival.

Papillary Solitary Fibrous Tumor/Hemangiopericytoma: An Uncommon Morphological Form With NAB2-STAT6 Gene Fusion.

Solitary fibrous tumor/hemangiopericytomas (SFT/HPCs) are mesenchymal tumors characterized by "staghorn" blood vessels and collagen deposition. Little is known about SFT/HPCs with papillary architecture. We summarized the clinicopathologic features of 12 patients with papillary SFT/HPCs (8 males and 4 females; median age: 59 years), including 8 previously reported cases. Tumors were present in the meninges (75%, 9/12), adrenal gland (8%, 1/12), orbit (8%, 1/12), or spinal canal (8%, 1/12). Six tumors (50%) had a true papillary architecture with fibrovascular cores and 6 tumors (50%) had a pseudopapillary architecture with vascular cores. Nuclear staining for STAT6 was present in all tested tumors (10/10). RT-PCR indicated NAB2 ex6-STAT6 ex17 fusion in 4 tumors (80%, 4/5) and NAB2 ex4-STAT6 ex2 fusion in 1 tumor (20%, 1/5). Five patients (42%, 5/12), all with tumors in the meninges, developed local recurrence at a median of 61 months after surgery (range: 56-165 months; mean: 88.6 months). These results indicated that the papillary architecture is a morphological form of SFT/HPCs. The recognition of this pattern, with appropriate immunohistochemical analysis and assessment of NAB2-STAT6 fusion, should facilitate the distinction of these rare neoplasms from morphologically similar tumors in the meninges, lung, pleura, and soft tissue.