Foamy gland microcarcinoma in needle prostatic biopsy

Atrophic and Microcystic Limited Prostatic Adenocarcinomas

Atrophic carcinoma and microcystic carcinoma have previously been classified as variants of conventional acinar adenocarcinoma. In this article, we studied 4 cases of atrophic carcinoma and 4 cases of limited microcystic carcinoma. We found an incidence of 0.8% in 250 needle prostatic biopsies and 1.3% of atrophic carcinoma in 150 radical prostatectomies. Microcystic carcinomas were found in 3 prostatectomies (1.2%) and in 1 needle biopsy (0.67%). The useful histological criteria for atrophic carcinoma included the irregular disposition of the glands, infiltrative pattern, "rigid" luminal borders, and intraluminal secretions. Cytological changes included scant cytoplasm, nucleomegaly, hyperchromatic nuclei, and visible nucleoli. The glands of the microcystic carcinoma differ from the benign glands because the malignant ones show a markedly greater dilatation and exhibit rigidity of glandular lumens. In some cases of microcystic carcinoma, the nuclei were flattened, small, and hyperchromatic; therefore, they can be difficult to recognize as malignant.

False-Negative Histopathologic Diagnosis of Prostatic Adenocarcinoma

Context.—

Histopathologic diagnosis of adenocarcinoma of the prostate is based on light-microscopic examination of hematoxylin-eosin–stained tissue sections. Multiple factors, including preanalytic and analytic elements, affect the ability of the pathologist to accurately diagnose prostatic adenocarcinoma. False-negative diagnosis, that is, failure to diagnose prostatic adenocarcinoma, may have serious clinical consequences. It is important to delineate and understand those factors that may affect and cause histopathologic false-negative diagnoses of prostatic adenocarcinoma.

Objectives.—

To review common factors involved in histopathologic underdiagnosis of prostatic adenocarcinoma, including the following: (1) tissue processing and sectioning artifacts, (2) minimal adenocarcinoma, (3) deceptively benign appearing variants of acinar adenocarcinoma, (4) single cell adenocarcinoma, and (5) treatment effects.

Data Sources.—

Data sources included published, peer-reviewed literature and personal experiences of the senior author.

Conclusions.—

Knowledge of the reasons for histopathologic false-negative diagnosis of adenocarcinoma of the prostate is an important component in the diagnostic assessment of prostate tissue sections. Diagnostic awareness of the histomorphologic presentations of small (minimal) adenocarcinoma; deceptively benign appearing variants including atrophic, foamy gland, microcystic, and pseudohyperplastic variants; single cell carcinoma; and treatment effects is critical for establishment of a definitive diagnosis of adenocarcinoma and the prevention of false-negative diagnoses of prostate cancer.

Minimal (Limited) Pseudohyperplastic Prostatic Adenocarcinoma in Needle Prostatic Biopsy

Background. Study of minimum adenocarcinoma has been done almost exclusively on conventional acinar adenocarcinoma. Pseudohyperplastic adenocarcinoma can be confused with benign lesions because of its well-differentiated appearance and has not been studied when the biopsy shows few malignant glands (limited carcinoma). Methods. We reviewed 94 pseudohyperplastic adenocarcinomas diagnosed in prostatic biopsies for a period of 12 years and selected those measuring less than 1 mm or involving less than 5% of the biopsied tissue. We also reviewed 200 consecutive consultations. Results. Four (4.2%) of the 94 cases were limited pseudohyperplastic adenocarcinomas, and 3 were from consultations. Three of them were mistaken for hyperplastic nodules, prostatic adenosis, or prostatic intraepithelial neoplasm. The number of glands varied between 6 and 50 (average 23). Three nodular histological patterns were identified—nodular, adenosis-like, and pseudohyperplastic carcinoma resembling prostatic intraepithelial neoplasia. The diagnosis of adenocarcinoma was not related to the number of neoplastic glands. Histological criteria that were useful included: crowded medium to large glands, papillary infoldings, branching glands, straight luminal borders, hyperchromatic nuclei, nucleomegaly, and apparent nucleoli. Areas of transition to conventional acinar adenocarcinoma were useful in recognizing four of these neoplasms, but were barely apparent in 2 of them. Hyperchromatic nuclei were found in all cases, whereas apparent nucleoli and nucleomegaly were only present in 4. Conclusions. The architectural and cytological criteria for limited acinar adenocarcinoma are only partially useful in interpreting minimum pseudohyperplastic adenocarcinomas. Knowledge of the criteria for malignancy in both neoplasms is important in order to avoid underdiagnosis of malignancy.

Pseudohyperplastic Adenocarcinoma With Foamy Changes in Needle Prostate Biopsy and Prostatectomy

Pseudohyperplastic adenocarcinoma (PHA) with foamy changes is composed of neoplastic glands that show a cytoarchitectural combination of both neoplasms. However, none of the previously reported cases have shown typical areas of foamy or PHA. We report on the clinicopathological characteristics of 5 cases consisting predominantly of pseudohyperplastic and foamy adenocarcinomas. In several histological fields, this neoplasm mimicked hyperplastic nodules or prostatic adenosis because they showed the nodular pattern of the PHA and the inconspicuous cytological atypia of foamy gland carcinoma. Four cases had a Gleason score of 6. In the prostatectomies, the neoplasm was limited to the prostatic gland. The evolution has been favorable in all patients after 3 years of follow-up, on average. The cases reported herein demonstrate that PHA and foamy adenocarcinoma may be associated and occasionally show overlapping histological criteria. The PHA with foamy changes must be distinguished from conventional foamy adenocarcinoma and PHA because it can closely resemble hyperplastic glands mainly in needle prostatic biopsy.

Morphologic Updates in Prostate Pathology

In the past several years, modifications have been made to the original Gleason system with resultant therapeutic and prognostic implications. Several morphologic variants of prostatic adenocarcinoma have also been described. Prostate pathology has also evolved over the years with the discovery and utility of new immunohistochemical stains. The topics discussed in this update include the Gleason grading system, prognostic grade grouping, variants of prostatic adenocarcinoma, and the application of immunohistochemistry to prostate pathology.

Expression and significance of cortactin and HDAC6 in human prostatic foamy gland carcinoma

Cortactin, the cytoplasmic substrate of HDAC6, is known to play an actin cytoskeletal regulatory role which is implicated in the motility of cancer cells, and thus in cancer progression. Its activity is found to be regulated by HDAC6. However, the significance of cortactin and HDAC6 remains unclear in uncommon histologic variant human prostatic foamy gland carcinoma (PfCa). In this study, we aimed to identify the expression and potential role of cortactin and HDAC6 in PfCa. Therefore, 16 PfCa specimens containing 48 foci with distinctive lesions were collected to identify the status of cortactin and HDAC6 by immunohistochemistry. Their correlation between clinicopathological characteristics and prognostic values were further analysed. The effect of cortactin and HDAC6 on prostate cancer cell migration and invasion was then evaluated in IA8 cells. The results showed that expression of cortactin and HDAC6 was significantly higher in PfCa foci, compared to that of high-grade prostatic intraepithelial neoplasia (HGPIN) foci and benign foci (P < 0.05). Cortactin and HDAC6 were associated with poor prognosis of patients with PfCa (P < 0.05). Multivariable Cox regression analysis showed HDAC6 level was a significant prognostic factor for survival of patients with PfCa (β = 1.200, Wald value = 7.282, P = 0.007, 95% CI = 1.389-7.941, P < 0.01, β > 0). Both knocking down cortactin and inhibition of HDAC6 activity with tubacin reduced in vitro migration and invasion ability of IA8 cells substantially. Furthermore, HDAC6 has prognostic value for patients with PfCa. Dysregulation of cortactin and HDAC6 is implicated in the invasiveness and migration of prostate cancer cells.

Pseudohyperplastic prostate carcinoma: histologic patterns and differential diagnosis

The similarity between some carcinomas and many benign glandular proliferations has been mentioned in the literature for decades. The description of the main histologic features of pseudohyperplastic carcinoma has been very useful in avoiding errors of interpretation, particularly false-negative results. In recent years, we have found some histologic variants of this neoplasm that have not been mentioned previously. In order to classify the different histologic growth patterns and comment on their differential diagnosis, we reviewed the architectural and cytologic features of 34 cases of pseudohyperplastic adenocarcinoma in 2 radical prostatectomies, 4 transurethral resections, and 28 needle biopsies. Growth patterns most commonly observed included nodular, complex, and mixed (nodular and complex) patterns. Other less frequent histologic varieties included adenosis-like pattern, prostatic intraepithelial neoplasia-like pattern, pseudohyperplastic adenocarcinoma with xanthomatous features, and limited pseudohyperplastic adenocarcinoma. Frequent changes in neoplastic glands included papillary infoldings, large/cystic glands, and branching. Criteria associated with malignancy include nuclear enlargement (92%), apparent nucleoli (85%), pink amorphous secretions (78%), and transition to small acinar carcinoma (70%). However, in some biopsies, nuclear atypia was little apparent. Fifteen of the 34 cases were misdiagnosed as benign and 5 as other malignant neoplasms, and included the following diagnoses: hyperplastic nodules (11), prostatic adenosis (2), diffuse adenosis of the peripheral zone (1), benign cystic glands (1), and less frequently other malignant tumors including xanthomatous carcinoma (2), low-grade prostatic adenocarcinoma (2), and atrophic carcinoma (1). It is important to recognize the different growth patterns of this neoplasm in order to avoid an underdiagnosis of malignancy.

Foamy gland carcinoma in core needle biopsies of the prostate: clinicopathologic and immunohistochemical study of 56 cases

Foamy gland carcinoma is a subtype of acinar adenocarcinoma characterized by foamy appearance, large cytoplasm, pyknotic nuclei, inconspicuous nucleoli and infiltrative pattern. In this study, we investigated the histological features and the incidence of foamy gland carcinoma. We compared foamy gland carcinoma with acinar adenocarcinoma according to age, prostate-specific antigen value, Gleason score, peripheral nerve invasion and accompanying high-grade prostatic intraepithelial neoplasia. Besides, we investigated the diagnostic value of immunohistochemical markers in foamy gland carcinoma. A total of 863 TRUS-guided prostate needle core biopsies performed at our hospital pathology clinic between January 1, 2010, and December 31, 2011, were examined, 251 of these were diagnosed acinar type adenocarcinoma. Conventional acinar type adenocarcinoma was present in 195 (78%) cases, and foamy gland carcinoma, in 56 cases (22%). We found that 11 (19%) of the 56 foamy gland carcinoma cases were pure and 45 (81%) cases were mixed with conventional acinar type adenocarcinoma. Single-core localization was present in 7 of 14 pure foamy gland carcinomas, and the number of cases with a Gleason score of 7 and above was 21 (37%). No statistically significant difference was found between foamy gland carcinoma and conventional acinar type adenocarcinoma in terms of age, Gleason score, high-grade prostatic intraepithelial neoplasia, and prostate-specific antigen values. Peripheral nerve invasion was found to be statistically significantly more common in foamy gland carcinoma compared to acinar type adenocarcinoma (P<.05). The staining percentage of immunohistochemical markers in foamy gland carcinoma was 90.1% for p63, 90.6% for 34Beta12 and 90.6% for AMACR.