Mills Ch35 Prostate

977

CHAPTER 35:  Prostate

FIGURE 35.33  Prostatic stromal hyperplasia is characterized by a relatively lobular or nodular proliferation of cytologically bland spindle cells associated with prominent small round blood vessels.

FIGURE 35.31  Postatrophic hyperplasia with atrophic acini in a lobular array surrounding a central dilated duct.

prostatectomy sections, these acini often seem to surround a dilated duct (Fig. 35.31), which has led some to use the alternate term “lobular atrophy.” The close packing of multi- ple small acini conveys a histologic impression of hyperplas- tic glands, yet whether this is truly a hyperplastic process or not remains unknown. The atrophic acini are often engulfed in a variable degree of fibrotic or sclerotic stroma. Cytologi- cally, postatrophic hyperplasia shows low cuboidal cells with scant cytoplasm and small- to medium-sized nucleoli. Like simple atrophy , chronic inflammation is often present, and the differential diagnosis of adenocarcinoma is often raised, especially in needle biopsy material. Partial atrophy is distinct from the other forms described here in that cytoplasm is attenuated, but is variably pres- ent, with a nonbasophilic appearance at low magnification. Characteristically, partial atrophy displays more cytoplasm lateral to the nucleus, increasing internuclear distance and imparting a pale low-power impression (Fig. 35.32). Small- to

medium-sized nucleoli, as well as intraluminal dense pink sections/crystalloids may mimic carcinoma. Partial atrophy is frequently seen admixed with foci of simple atrophy suggest- ing that they represent a spectrum of atrophic changes. In contrast to atrophy, the histologic hallmark of BPH is the expansile nodule, produced by the budding and branch- ing of newly formed duct–acinar structures, by the focal proliferation of stroma (Fig. 35.33), or by a combination of both elements (Fig. 35.34) (3,4,7,44). It mainly affects the transition zone.

FIGURE 35.32  Focus of partial atrophy with attenuated pale cytoplasm andwispy eosinophilic intraluminal secretions. The nuclei appear relatively evenly spaced due to retention of the lateral cytoplasm.

FIGURE 35.34  Nodule of glandular benign nodular hyperplasia in the prostatic transition zone.