Prostatic adenocarcinoma metastases mimicking small cell carcinoma on fine-needle aspiration

Metastatic prostate cancer diagnosed by fine-needle aspiration: Contemporary cytopathologic and biomarker assessment with clinical correlates

INTRODUCTION

The diagnosis of metastatic prostatic cancer (MPC) by fine needle aspiration (FNA) can usually be rendered by typical cytomorphologic and immunohistochemical (IHC) features. However, MPC diagnosis may be complicated by transformation to atypical phenotypes such as small cell carcinoma, typically under pressure from androgen deprivation therapy (ADT). Predictive and prognostic biomarkers can also be assessed by IHC. This study illustrates how careful assessment of cytologic and biomarker features may provide therapeutic and prognostic information in MPC.

DESIGN

We reviewed our anatomic pathology archives for MPC diagnosed by FNA from January 2014 to June 2021. Clinical histories, cytology slides, and cell blocks were reviewed. Extensive IHC biomarker workup was performed, including markers of prostate lineage, cell-cycle dysfunction, Ki-67, neuroendocrine markers, PDL1, and androgen receptor splice variant 7. Cases were reclassified into three categories: conventional type, intermediary type, and high-grade neuroendocrine carcinoma (HGNC).

RESULTS

Eighteen patients were identified. Twelve had conventional MPC, including six of six ADT-naive patients. Six of twelve (50%) with prior ADT were reclassified as intermediary or HGNC. Four intermediary cases included two with squamous differentiation and two with pro-proliferative features. Two HGNC cases had typical small cell carcinoma cytomorphology. Expression of PDL1 was identified in two cases and ARv7 in three cases. Five of five intermediary and HGNC patients died of disease versus six of eleven with with conventional type.

CONCLUSIONS

Aggressive cytomorphologic variants were commonly identified in patients with prior ADT. Identification of nonconventional cytomorphology and increased proliferation can provide important prognostic information. Recognition of these changes is important for an accurate diagnosis, and the identification of high-grade variants can affect therapeutic decision-making. Clinically actionable biomarkers such as PDL1 and ARv7 can be assessed by IHC.

Metastatic prostate carcinoma presenting as a gluteal soft tissue mass

Metastatic lesions from prostate adenocarcinoma to the bone and lymph nodes and less frequently to the lungs, pleura, liver and adrenal glands are well documented. The presence of soft tissue metastases from a prostate adenocarcinoma is extremely rare. We report a case of a 56-year-old male who presented with a 2-year history of a painless buttock mass. MRI showed a well-defined, right gluteal intermuscular soft tissue mass and multifocal hypointense lesions of the pelvic bones and appendicular skeleton suggestive of secondary metastatic disease. Tru-cut biopsy of the gluteal mass demonstrated metastatic adenocarcinoma. Further workup showed an elevated prostate-specific antigen, and acinar adenocarcinoma of the prostate was confirmed on transrectal biopsy of the prostate. Androgen deprivation therapy with long-acting three monthly goserelin and short-term cover with bicalutamide was initiated as was systemic taxane-based chemotherapy. He has shown an excellent PSA response and remains asymptomatic with complete resolution of the size of the gluteal metastasis at the most recent follow-up 9 months later.

A Case of Metastatic Prostate Cancer to the Distal Phalanx

Metastatic bone tumors to the hand are extremely rare. We present a case of metastatic prostate cancer to the right middle finger distal phalanx. To our knowledge, there is one other case of metastatic prostate cancer to the hand in the literature. In our case, a 59-year-old man with a history of widely metastatic prostate cancer presented to urgent care and was diagnosed with a nail plate avulsion injury. He was referred to hand surgery and treated with amputation of the right middle finger distal phalanx. The pathology reported high-grade poorly differentiated adenocarcinoma with primary lesion from the prostate.

Metastatic Prostate Cancer of Hand

Soft tissue metastases of prostate cancer to other sites are extremely rare, and, to our best knowledge, there have been no reports of metastasis to soft tissue of the hand. A 63-year-old man was diagnosed with prostatic cancer. During treatment, bone and soft tissue metastases to the right hand, appearing in the first web space, were observed. The tumor was resected, along with both the first and second metacarpal bones. The thumb was reconstructed by pollicization of the remaining index finger, enabling the patient to use the pollicized thumb for activities of daily living. This is the first case report of prostate cancer metastasizing to the soft tissue in hand. After wide resection, pollicization was able to reconstruct a functional hand and thumb.

The utility of PSMA and PSA immunohistochemistry in the cytologic diagnosis of metastatic prostate carcinoma

The diagnosis of metastatic prostate carcinoma frequently requires the use of immunohistochemical adjuncts. Immunohistochemistry for prostate-specific antigen (PSA) is commonly used for this purpose but can be of limited utility. Recently, prostate-specific membrane antigen (PSMA) has been shown to be a promising marker for the identification of metastatic prostate carcinoma in surgical specimens. The utility of this marker has yet to be reported for cytology specimens. We sought to compare the sensitivities of PSMA and PSA immunohistochemistry and investigate the specificity of PSMA by utilizing cell block preparations from cytologic cases of metastatic prostate carcinoma (n = 19) and carcinomas of nonprostatic origin (n = 33). The sensitivity of PSMA immunohistochemistry was higher (16/19; 84%) in detecting metastatic prostate carcinomas than that of PSA immunohistochemistry (11/19; 58%). Strong, diffuse staining for PSMA was seen in 13 (81%) of 16 PSMA-positive cases whereas strong, diffuse staining for PSA was observed in six (55%) of 11 PSA-positive cases. Positivity for either PSMA or PSA was seen in 17 of 19 cases of metastatic prostate carcinoma for a combined sensitivity of 89%. PSMA immunohistochemistry was completely negative in 32 of 33 cytology cases of nonprostatic carcinomas. Therefore, the specificity of this marker was 97% in this study. In conclusion, our results indicate that PSMA is a highly sensitive and specific immunomarker for the detection of metastatic prostate carcinoma in cytology specimens.

Urinary cytomorphology and clinical correlates of prostatic small cell neuroendocrine carcinoma

BACKGROUND

Small cell carcinoma (SCC) of the prostate represents a rare form of prostatic carcinoma. While the tumor is often considered to arise from neuroendocrine proliferation or possibly dedifferentiation of an acinar carcinoma, the precise etiology remains uncertain. The diagnosis of prostatic SCC in urine has to date not been described.

METHODS

A retrospective review was performed at a tertiary-care hospital, and 3 patients with prostatic SCC in voided urinary specimens were identified. The following clinical data were collected for each case: age, gender, treatment and follow-up information, when available.

RESULTS

The patient age range was 70-86 years, all male. Two patients had known metastatic adenocarcinoma of the prostate, and 1 had recently presented with prostatic SCC. One patient with metastatic disease died shortly after diagnosis, the other was lost to follow-up. The third patient with a recent presentation has yet to have a treatment plan finalized.

CONCLUSIONS

Our results highlight the importance of making this uncommon diagnosis as it may carry significant treatment and prognostic importance. Future work should hopefully clarify the role of ERG gene rearrangements in the pathogenesis of prostatic SCC, as there is a potential role here for targeted therapy.

Prognostic significance of neuroendocrine differentiation in prostate adenocarcinoma

Much progress has been made toward an understanding of the development and progression of prostate cancer (PC) and the factors that drive the development of androgen independence. Neuroendocrine (NE) cells may provide an intriguing link between NE cell differentiation (NED) and tumor progression in PC. NED in PC generally confers a more aggressive clinical behavior and less favorable prognosis than conventional PC. In this article, we review the known functions of NE cells in PC and discuss the current knowledge on stimulation of cancer proliferation, invasion, apoptosis resistance, serum and immunohistochemical markers, and the prognostic significance of NED in human PC.

Fine needle aspiration of metastatic prostate carcinoma simulating a primary adrenal cortical neoplasm: a case report and review of the literature

Adrenal metastases usually occur in prostate cancer patients with widespread bone and visceral disease. Autopsy studies have shown that adrenal metastases may be found in up to 23% of these patients. However, the finding of an isolated adrenal metastasis without the involvement of other organs in a patient with prostate cancer is exceedingly rare. Thus, it may cause a diagnostic dilemma on FNA cytology. We report a patient with a history of prostate cancer, status post radiation, and hormonal therapy 4 years before, who presented with a new, single adrenal mass on abdominal imaging studies. The ultrasound-guided FNA cytology of the adrenal mass revealed cytomorphological features that were suggestive of a primary adrenal cortical neoplasm, but overlapped with those of a prostate metastasis. To our knowledge, FNA findings of metastatic prostate cancer simulating an adrenal cortical neoplasm have not been previously reported in the English literature. The purpose of our study is to discuss the differential diagnosis of these entities. The accurate diagnosis is important because of different prognosis and treatment implications for the various diseases.

Cytology of metastatic prostate cancer following orchiectomy and antiandrogen therapy: a diagnostic challenge

Androgen deprivation therapy induces apoptosis and decreases both cell proliferation and angiogenesis in prostate adenocarcinoma. The molecular alterations following androgen ablation translate into unique cytologic features in both primary and metastatic prostate adenocarcinoma. We describe the cytologic appearance of metastatic prostate carcinoma following both surgical castration and androgen deprivation therapy.

Fine needle aspiration biopsy diagnosis of metastatic prostate carcinoma to inguinal lymph node

Carcinoma of the prostate is predominantly a disease of older men. Men younger than 50 years of age account for approximately 1% of all patients diagnosed with prostate cancer. Patients generally present with urinary symptoms and rarely with metastatic disease. Lymphatic spread typically occurs to the obturator and internal iliac nodes. We report a case of an aggressive prostate adenocarcinoma in a 47-year-old white male who presented with nausea, vomiting, and enlarged inguinal lymph nodes for 1 month. A fine needle aspiration biopsy (FNAB) and immunohistochemical stains performed on the FNAB revealed metastatic prostatic adenocarcinoma. The initial clinical presentation of inguinal lymphadenopathy, the age of the patient and the cytologic features made this an unusual case.

Secondary prostatic adenocarcinoma: A cytopathological study of 50 cases

Positive diagnosis of metastatic prostate adenocarcinoma (PAC) can be made by microscopic examination of the cytologic specimens and immunostaining for prostate-specific antigen (PSA) and prostate acid phosphatase (PAP). Immunohistochemical markers have been known to display negative, weak, or focal staining in poorly differentiated PAC and in patients with prior hormonal and/or radiation therapy. The purpose of this study is to characterize the cytopathology of metastatic PAC as it has not been documented in large series. Fifty cases of metastatic PAC with cytological specimens consisting of 41 fine-needle aspiration biopsies (FNAB), 6 pleural fluid aspirates, and 3 catheterized urine samples were reviewed and correlated with the surgical specimens and the clinical charts. Immunostaining for PSA, PAP, cytokeratin AE1/3, cytokeratin 7 (CK7), cytokeratin 20 (CK20), vimentin, and carcinoembryonic antigen (CEA) was done. Mean patient age was 77 +/- 8 yr; serum PSA, 4.1 +/- 2.3; and primary PAC Gleason score, 8.1 +/- 1.5. Cytologically, the specimens consisted of cell clusters or cell sheets with overlapping uniform hyperchromatic nuclei with or without nucleoli. Twelve cases were not reactive to PSA and PAP and 44 cases displayed negative immunoreactivity to both CK7 and CK20. Carcinoid-like lesions and small cell carcinomas were seen in 4 cases and were misdiagnosed as nonprostatic origin based on the following features: negative immunoreactivity to PSA and PAP with or without positive reactivity to CEA, and different histopathological features when compared with the primary PAC. In addition to the frequency of high-grade PAC, awareness of the negative immunoreactivity to PSA and PAP, the discrepancy in the histopathological patterns between the primary and secondary tumors, especially the frequent neuroendocrine differentiation, are helpful features for the diagnosis of metastases of prostatic origin.

Small-cell tumors of the liver: A cytological study of 91 cases and a review of the literature

This study was designed to consider the cytomorphological spectrum, differential diagnosis, and the role of ancillary studies in small-cell tumors of the liver. Three independent pathologists reviewed cytological slides from 91 cases of small-cell tumors of the liver. The results were compared with the findings of three recently published studies (Cytopathology 11 (2000) 262-267; Diagn Cytopathol 19 (1998) 29-32; and Acta Cytol 40 (1996) 937-947). The role of immunohistochemistry in reaching timely and specific diagnoses was also examined. The diagnostic categories included 44 cases of metastatic small-cell undifferentiated carcinoma, 15 cases of metastatic neuroendocrine carcinoma, 10 cases of metastatic adenocarcinoma, 7 cases of malignant lymphoma, 4 cases of hepatocellular carcinoma with small-cell features, 2 cases of cholangiocarcinoma, 1 case of poorly differentiated carcinoma, and 8 cases of rare tumors including granulosa cell tumor (2 cases), sarcoma (4 cases), malignant melanoma with small-cell features (1 case), and meningioma with small-cell features (1 case). Metastatic granulosa cell-tumor, metastatic melanoma, and metastatic meningioma should be included in the differential diagnoses of small-cell malignancies found in the liver.