Calcifying Prostatic Glands in an Adult

Specimen Type:

Prostate

History:

A 54-year-old male with an elevated serum PSA underwent prostate needle biopsies.

Pathologic Features:

At low magnification, there are a good number of crowded glands occupying nearly one third length of one biopsy core (Fig. 4.1). Blue-stained calcific deposits are present in the majority of glands (Fig. 4.1). The glands are pale, variable in size, and some appear distorted (Fig. 4.2), or atrophic (Fig. 4.3). At higher magnification, the cells have abundant cytoplasm, with finely dispersed chromatin, slightly enlarged nuclei, and inconspicuous nucleoli (Fig.4.4). Individual glands display nuclear hyperchromasia and prominent nucleoli (Fig. 4.5). Basal cell layer can not be appreciated histologically.

Differential Diagnosis:

  • Typical adenomatous hyperplasia (Fig. 4.6, 4.7)
  • Calcifying prostatic adenocarcinoma

Atypical adenomatous hyperplasia (AAH): AAH is invariably an incidental finding, mostly seen in TUR or prostatectomy specimens, and only minority is (less than 1%) seen in needle biopsy. Histologically, AAH typically is a well-circumscribed collection of densely packed small, pale, acini, which merge with larger, more complex glands. The periphery of the aggregate is characteristically round, but in a minority of cases, the small acini can extend into surrounding stroma in an infiltrative pattern. Cytologically, the cells lack prominent nucleoli. Basal cell layer can be difficult to discern in some acini, and its presence is usually confirmed with the use of the immunohistochemical staining with CK34BE12.

Calcifying prostatic adenocarcinoma: Prostate cancer with calcifying glands is rare, and may be present on needle biopsy. Glands can be benign-looking cytologically, but the diagnostic architectural and cytological features of cancer should be retained.

Diagnosis:

Calcifying Prostatic Adenocarcinoma

Key Features:

  • Rare, may be present on needle biopsy
  • Architecturally, infiltrative
  • Calcific deposits in the lumen of acini
  • Benign-looking glands are present, but glands with malignant features such as nuclear enlargement and hyperchromasia, and prominent nucleoli, are invariably seen
  • Absence of basal cell layer, sometimes needs to be confirmed with the aid of immunostain

Comment: Prostatic adenocarcinoma can present itself with a variety of morphologies; some cancer glands look quite innocent architecturally or cytologically, such as atrophic, and calcifying as seen in this case. Relatively common, although still rare, is prostatic adenocarcinoma with atrophic features, and this type of cancer has been well documented (references 1, 2). However, prostate cancer with calcifying feature is not well recognized. The diagnosis in this case is not difficult due to the presence of a plenty of glands showing an infiltrative pattern, and individual glands with prominent nucleoli, but in case of modest glands available, the diagnosis can be problematic and cancer may be overlooked due to the benign impression of calcifying glands. Recognization of this calcifying feature, which can be associated with cancer, can prompt you to further investigate the true nature of similar lesions whenever you encounter in routine practice.

References:

  1. Egan AJ, Lopez-Beltran A, Bostwick DG. Prostatic adenocarcinoma with atrophic features: malignancy mimicking a benign process. Am J Surg Pathol. 1997 Aug; 21(8):931-5.
  2. Kaleem Z, Swanson PE, Vollmer RT, Humphrey PA. Prostatic adenocarcinoma with atrophic features: a study of 202 consecutive completely embedded radical prostatectomyspecimens. Am J Clin Pathol. 1998 Jun;109 (6):695-703.