Benign fibrous histiocytoma of the renal capsule

Deep benign fibrous histiocytoma occurring in the kidney: Case report

RATIONALE

Deep benign fibrous histiocytoma (BFH) is relatively rare in contrast to superficial BFH involving the skin. Moreover, it was extremely rare for deep BFH occurring in the solid organ. To our knowledge, so far, only one case of deep BFH of the kidney was reported in English literature.

PATIENT CONCERNS

Herein, we report another case of deep BFH located in the kidney in a 88-year-old female. She was referred to our hospital for a severe pain in the right upper abdomen. Computed tomography revealed a round low-density shadow measuring 6 cm in the kidney.

DIAGNOSIS

The lesion was diagnosed as a deep BFH of the kidney, as the tumor was histologically predominately composed of bland ovoid cells arranged in a storiform pattern.

INTERVENTION

The patient underwent the total resection of the right kidney with the tumor in our hospital.

OUTCOMES

The postoperative course was uneventful. The patient was alive with no tumor recurrence or metastasis within 6 months of follow-up.

LESSONS

We present another case of deep BFH of the kidney. Because of the rarity, the tumor may be poorly recognized. The typical storiform pattern in histology may be helpful for diagnosis. This report serves to remind that deep BFH is also a differential diagnosis for a tumor with storiform pattern in the kidney.

A huge benign fibrous histiocytoma arising from the renal capsule: report of a case

Background

Neoplasms originating in the renal capsule are very rare. Benign fibrous histiocytoma(BFH) most commonly occurs in the dermis and subcutis, few cases of this tumor appear in the renal capsule. In particular, BFH larger than 20 cm are scarce. Here we report a rare huge one measuring 23 × 13 × 7 cm.

Case presentation

We report a 64-year-old man who presented with a few-months history of dull pain in the right groin. The tumor had its point of origin in the renal capsule which is a rare condition. Histologically, the tumor was composed of intersecting fascicles of fibroblastic cells forming a “storiform” pattern. Immunohistochemical studies were also performed, ultimately leading to the diagnosis of BFH. The patient was treated with radical nephrectomy. No recurrence was detected 4 months after surgery.

Conclusions

BFH arising from the renal capsule was very rare. In particular, the case of more than twenty centimeters is extremely rare. The clinical presentation of renal BFH might be only a mass. However, differential diagnosis from renal cell carcinoma proved to be impossible before surgical intervention. It is difficult to diagnose only by means of histopathology, but the immunohistochemical method can provide a clear and definite diagnosis.