Sebaceous tumors

Reactivity for EMA and related substances is often obtained in sebaceous tumors, and these substances are typically displayed in a unique manner in these neoplasms. In both benign and malignant sebaceous proliferations, a characteristic microvesicular or bubbly cytoplasmic profile of the mature sebocyte is often maintained (Eig. 13.8). EMA staining in such neoplasms is comparable to that seen in non-neoplastic sebaceous epithelium, in that cytoplasmic lipid vesicles are rimmed by EMA reactivity. Even in poorly differentiated sebaceous carcinomas, EMA stains may highlight otherwise inapparent cytoplasmic multivacuolization. ... 

The pathologic distinction between primary sebaceous carcinoma and metastatic renal cell carcinoma (RCC an important differential diagnostic alternative with a clear-cell appearance) is similar to that made earlier in reference to sweat gland carcinomas. Slow evolution of a solitary skin tumor favors a primary lesion. In addition, immunostaining for podoplanin is effective in this context that determinant is consistently present in sebaceous tumors, whereas it is absent in RCC. CD 10 is potentially seen in both lesional categories. TSS... 

An increased incidence of neoplasms at multiple sites has been found in chronic inhalation and gavage smdies in rodents. Anemia, lymphocytopenia, bone marrow hyperplasia, and an increased incidence of lymphoid tumors occurred in male mice exposed at 3 00 ppm for life. " Gavage administration to rats in one study, and rats and mice in another, caused an increase in tumors especially significant was an increase in zymbal gland tumors (tumors of the auditory sebaceous glands) in both reports. ... 

Of 111 rats given 20mg of DCB hy injection or gastric intuhation 6 days/week for 10-20 months, 17 had tumors of the zymbal gland (a specialized sebaceous gland adjacent to the external ear canal), 13 had mammary tumors, 8 had skin tumors, 5 had malignant lymphomas, 3 had urinary bladder tumors, 3 had salivary gland tumors, and 2 had intestinal tumors no tumors were found in 130 control... 

Male rats treated with isophorone in the NTP (1986) study also had preputial gland carcinomas, an extremely rare finding. Analogous tissues in humans are modified sebaceous glands in the prepuce (foreskin of the penis), but it is not known whether isophorone could cause tumors in these glands or other glandular tissues in humans. 

Animal carcinogen. Oral or parenteral administration to rodents causes tumors in the liver, mammary gland, urinary bladder, intestinal epithelium, and sebaceous glands of the ear duct. Mutagenic and slightly toxic. Reasonably anticipated to be a human carcinogen.3... 

The histologic appearance varies not only between tumors but also within the same neoplasm. Some areas of the tumor may be composed primarily of clear cells with only few widely scattered ducts, whereas other areas may be composed primarily of ducts. Sebaceous differentiation is also possible, as are other types of cellular differentiation such as oncocytic changes. 

Sebaceous and sweat gland tumors CD15+ and BerEP4+... 

---