Adenomatoid tumors are composed of two major elements the epithelial component and the fibrous stroma. the epithelial component is arranged in tubules, cords and nests withe cells that are flat, cuboidal to low columnar with round or oval nuclei and abundant dense cytoplasm however the cells might contain cytoplasmic vacuols and sometimes it’s so extensive that it results in signet ring like morphology as in the case of this gentle man how presents with painless small 2 cm mass in the epididymis. one should not confuse this with metastasizing signet ring carcinoma as adenomatoid tumors are very common only second to cord lipomas in such locations. Negative CEA immunostain will rule out adenocarcinoma.
AMLs are composed of variable amounts of adipose tissue, smooth muscle, and vasculature . More than 90% of tumors contain at least focal areas of mature adipose tissue . Fat cells resembling lipoblasts are rarely seen. The smooth muscle component ranges from fascicles of elongated spindle cells with cigar-shaped nuclei to sheets of epithelioid cells with abundant eosinophilic granular cytoplasm. The smooth muscle cells often appear to originate and radiate from vessel walls. The morphology of the vascular component is variable. Thickened and hyalinized vessels with eccentric lumens are seen in most cases. Antibodies to several melanoma-related antigens, including HMB-45 and A-103 (melan-A/MART-1), are at least focally positive in the majority of cases. In general, from 5% to 10% of cells are immunoreactive with these antibodies . The epithelioid smooth muscle cell components are most consistently positive with these antibodies, although the spindled smooth muscle and adipose tissue components also may be positive. This observation is of particular importance in the subset of AML with a predominance of adipose tissue or spindled smooth muscle. (Sternberg’s 5th ed).
Hi there, few days ago i stumbled upon this relatively uncommon renal tumor and misdiagnosed it as Conventional renal cell carcinoma on smears. ” seams i got so much to learn ”
So lets review the Cytological Characteristics of this tumor :
- polygonal cells.
- well defined borders.
- granular to light transparent cytoplasm, clear cells are rare.
- accentuation of the granularity at the periphery of the cell.
- central halo giving the cell koilocyte like appearance.
- the nuclei are eccentric with anisonucleosis.
- some of the nuclei are condensed with raisinoid appearance.
Beware of the Eosinophilic Variant of Chromophobe RCC as it very hard to differentiate from Renal Oncocytoma which is a benign tumor.
40 years old male patient with testicular mass, the patient underwent radical orchidectomy and this is a smear from the tumor. you can see here the typical features of the germ cell tumor Seminoma classical variant, which are :
– highly cellular smears
– multiple bizarre nucleoli seen in side the nuclei
-infiltrating reactive lymphocytes ” smaller and darker in color ”