Kimura disease with proliferative squamous metaplasia: an unusual finding and a potential diagnostic pitfall.

Kimura disease is a rare form of chronic inflammatory disorder involving subcutaneous tissue, predominantly in the head and neck region and frequently associated with regional lymphadenopathy and/or salivary gland involvement. We present a case of Kimura disease in a 28-year-old male which showed florid squamous metaplasia in the salivary gland ducts and salivary duct inclusions in the intraparotid nodes besides the usual features of Kimura disease. The squamous metaplasia was extensive enough to pose a diagnostic dilemma. We describe this case to highlight the rare histological finding of florid squamous metaplasia in Kimura disease and its diagnostic implications.

Clear cell sarcoma of the kidney--a study of seven cases over a period of three years.

Clear cell sarcoma of the kidney (CCSK) can display diverse morphological patterns and mimic various other pediatric renal tumors. An accurate diagnosis of this tumour is important considering the therapeutic and prognostic implications. AIM: The present study was undertaken to describe the various histological patterns of CCSK. The histology of 7 cases and the available case files of CCSK accrued over a period of3 years were reviewed. Immunohistochemical (IHC) stains were performed in 3 cases. The histological patterns observed in this study were classical (observed in 4 cases), epithelioid trabecular, myxoid, palisading and hyaline sclerosis types. IHC revealed reactivity to vimentin and non-reactivity to cytokeratin, desmin, smooth muscle actin, neuron specific enolase (NSE) and S-100 protein. Since CCSK is essentially a histological diagnosis, the importance of an accurate diagnosis of CCSK by a pathologist cannot be overemphasized. This study describes the various histological patterns that can be observed in CCSK.

Renal angiomyolipomas--a study of 18 cases.

Angiomyolipoma is a distinctive neoplasm composed of an intimate admixture of three components, viz. mature adipocytes, smooth muscle cells and blood vessels. This study was undertaken to better define the various morphological patterns of angiomyolipoma and their immunohistochemical profile. The paraffin blocks and slides of 18 cases of renal angiomyolipoma, accessioned over a period of 8 years from Tata Memorial Hospital, were reviewed. There were 2 men and 16 women in the age range of 17 to 68 years. Pre-operative fine needle aspiration cytology (FNAC) was performed in 6 cases, of which 5 were erroneously diagnosed as renal cell carcinomal sarcoma. Histologically, 14 cases revealed conventional histology. The remaining 4 cases were particularly misleading posing diagnostic problems due to variant patterns (leiomyomatous variant-3 cases and epithelioid variant- 1 case). Apart from the usual histology, necrosis, giant cells, and varying degrees of nuclear pleomorphism were present in three of the cases. Immunohistochemistry performed in 16 cases revealed immunoreactivity for HMB45 in all the 16 tumors (100%), estrogen receptor (ER) and progesterone receptor ((PR) in 2 cases (12.5%) and 6 cases (37.5%) respectively.