Arteriovenous malformations (AVMs) are type of vascular malformation most relevant to the surgical pathologist. Because their vessels tend to leak and induce gliosis. AVMs can present with seizure disorder and also cause spontaneous hemorrhage. Best seen by trichrome or elastic stains, AVMs manifest artery-vein connections with associated arterialization of veins. Arterialization is thickening of a venous wall to the point where it resembles an artery, possibly due to fibrotic reaction to shunted arterial blood. Arteries show irregular duplication or loss of elastin . Thrombi are common. (Sternberg’s 5th ed)
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).
GCTTS is a very common Benign tumor usually affecting the digits in females ( 2x more common) grossly it is a lobulated small (2-3 Cm.) yellowish mass.
Here in our case we can see :
- osteoclast like gaint cells with many bland looking nuclei.
- many mononuclear cells in the back ground.
- Not much inflammatory cells or hemosidren.
The differential here:
- pigmented villonodualr tenosynovitis – usually in large joints like knee with lots of hemosidren.
- other granulomatous lesions – many inflammatory cells.
- mononuclear cells stain with Desmin
- you may see necrosis , tumor thrombi on paraffin sections.
Neoplastic vs reactive nature is still one of the questions to be solved.
This patient underwent total abdominal hysterectomy and bilateral oopherectomy due to endometrial complex hyperplasia with atypia, the left ovary showed a mass ” couldn’t resist the temptation of taking a smear for fast pap stain” which showed this spindle tumor with fasicular arrangement. the tumor later proved to be a fibrothecoma quit known to screte lots of estrogen that may lead to hyperplastic endometrium. strangly the cells on smears showed many grooves as on sections a feature seen in estrogen secreting granulosa cell tumor.
- The smears are hyper cellular.
- cells appear singly or in loose groups or pseudo rosettes.
- Three types of cell have been described:
- The first type is small to moderate-sized polygonal cells with finely granular cytoplasm and uniform roundor oval nuclei with granular chromatin and prominent chromocenters. These cells are the prototypic cells of neuroendocrine tumors.
- The second type is spindle cells with abundant cytoplasm, elongated nuclei, and coarse granular chromatin.
- large, myoid-like cells with eccentric large nuclei, prominent nucleoli, and abundant pale, finely granular cytoplasm.
The smears may be composed of a mixture of these cell types or one cell type may predominate. “M.BIBO 3rd ed”
Aspirating a pheochromocytoma is dangerous as it may precipitate a hypertensive crisis.
Remember the rule of 10% and multiple endocrine neoplasia association.
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.
-Long slender tapering nuclei sometimes bend and form hooks and comma shapes.
– Fibrillari back ground.
– Watch out from degenerative changes which including pleomorphism.
– If you find verocay bodies you are lucky
This case is dedicated to our dear colleague and friend Ahmed AboSolb, leaving us soon. your case is solved from the very first day 🙂