ABSTRACT
Collision tumor is a phenomenon in which two histologically different tumors exist as distinct lesions within the same organ. Occurrence of two different, synchronous, and ipsilateral renal tumors is rare. We present a case of two synchronous tumors of kidney comprising of clear cell renal cell carcinoma [CCRCC] and chromophobe renal cell carcinoma [CRCC]. Grossly, two separate tumor nodules were identified with unremarkable intervening area. Microscopic examination from both tumor nodules revealed two different epithelial malignancies. It is prognostically significant as prognosis in such cases is determined by the more aggressive of the two tumors. In this case, CCRCC is more aggressive with a 5-year survival rate of 50-60 % as compared to CRCC with a 5-year survival rate of 80-90%
ABSTRACT
Malignant triton tumor [MTT] is a tumor arising from Schwann cells with divergent rhabdomyoblastic differentiation.It is a relatively rare and aggressive variant of malignant peripheral nerve sheath tumor [MPNST]. We present a case of a 33 years old male with thigh swelling. Surgical excision was done followed by histopathological and immunohistochemical [IHC] workup which revealed a tumor showing two types of cell populations including pleomorphic spindle cells and large cells with pleomorphic eccentric nuclei. Spindle cells showed positivity for S-100 IHC stain confirming their neural origin while large cells with eccentric nuclei showed positivity for desmin and myogenin IHC stains confirming their rhabdomyoblastic origin. Hence, the diagnosis of MTT was made. A 5 years survival rate for MTT is 5-15% compared to 50-60% for MPNST. Considering it is a rare entity with aggressive clinical behavior and poor prognosis, correct diagnosis is essential that can be achieved by careful histological and IHC evaluation