A middle aged female presented with a large flank mass, was initially reported to be a renal cell carcinoma of the sarcomatoid variant. Discordant presentation lead to further pathological work-up and a primary renal synovial sarcoma was diagnosed. We present our journey in images.

Introduction Inflammatory myofibroblastic tumor is a benign entity that may present as a locally aggressive malignancy, predominantly in the lung. 500 cases have been reported in the literature, and an estimated prevalence ranges from 0.04% to 0.7%. Case presentation An eighteen-year old male presented to the surgical clinic with abdominal pain. The pain was recurring despite trials of analgesics and remained undiagnosed. Radiological imaging demonstrated a lesion in the spleen. An infectious cause was presumed due to their endemicity in South Asia, however pathology showed an inflammatory myofibroblastic tumor. Discussion Pre-operative imaging is yet to develop a set criterion that may identify this lesion, though clinicians may be clued in by the benign appearance despite the large size. Usual diagnosis is on pathology after complete surgical excision, which is the mainstay treatment advocated. Conclusion Reporting of the tumor in unusual sites such as the spleen is scarce, increase of which may help establish guidelines, understand tumor behavior and guide clinicians that may encounter it in surgical practice.

A large flank mass was reported as a renal cell carcinoma of sarcomatoid variant.It had discordant clinical presentation; on further pathological work-upwith t(X;18), diagnosis of a synovial sarcoma was made.Forty-five-year-old female patient with right flank pain made multiple visits to rural general practitioners in Pakistan a year preceding presentation. Computed tomography scan reported "Massive heterogeneous mass replacing the whole of the right kidney, with residual scanty renal tissue, at its medial aspect." During surgery a 15 × 18 cm mass involving the inferior vena cava was excised. (Figure 1).Histopathology reported a 19 × 17 × 11 cm mass, involving the upper and lower pole adherent to the capsule with necrosis present. Lymph nodes free of tumor with positive markers: CK, Vimentin, TLE-1, CD99, EMA, Cytokeratin AE1/AE3 and Cytokeratin 20.Renal cell carcinoma, sarcomatoid variant was diagnosed, metastases were absent, and clinical presentation was discordant with reported aggressive tumor behavior.