Cancer Cytopathology

In this issue, 2 groups of authors investigate the diagnostic usefulness of the immunohistochemical marker arginase-1 in the evaluation of hepatic masses using fine-needle aspiration. Both groups propose that arginase-1 join 2 other immunohistochemical stains, hepatocyte paraffin and glypican-3, which are commonly used in the often challenging diagnosis of liver lesions.

The authors focus their expertise in the area of peritoneal washings on the detection of gynecologic neoplasms, specifically on the challenging area of ovarian serous tumors of low malignant potential. Particular attention is paid to the cytomorphologic differential diagnosis with endosalpingiosis; investigation of the prognostic significance of positive peritoneal washings is advanced.

Arginase-1, along with HepPar-1 and glypican-3, can be helpful in the diagnosis of hepatocellular carcinoma and its separation from metastatic carcinoma.

Arginase-1 is a sensitive marker of hepatic differentiation and is particularly useful in poorly differentiated hepatocellular carcinomas, which frequently lack HepPar-1 immunoreactivity.

Peritoneal washing cytology detects the presence of peritoneal implants in patients with ovarian serous tumors of low malignant potential with moderate accuracy, but it cannot distinguish between invasive and noninvasive implants. Long-term studies are needed to determine whether positive cytologic findings are an independent predictor of tumor recurrence.

The Bethesda System for Reporting Thyroid Cytopathology predicts the presence of adverse pathological risk factors and disease progression when the malignancy is papillary thyroid carcinoma (PTC). These differences may have implications for clinical management, because malignant diagnoses identify higher risk PTCs and atypia of undetermined significance identifies mostly low-risk follicular variant PTCs.

The current series describes cytomorphologic findings of nodular lymphocyte-predominant (LP) Hodgkin lymphoma on fine-needle aspiration (FNA) with a discussion of common pitfalls and differential diagnosis. Because the entity is often mistaken for reactive lymphoid hyperplasia, a careful search using high magnification for LP cells is recommended in the evaluation of lymph node FNAs.

Intrapancreatic accessory spleen (IPAS) is a rare benign lesion of the pancreas that frequently mimics a solid neoplasm. If IPAS is recognized as a diagnostic consideration on endoscopic ultrasound fine-needle aspiration, unnecessary surgical resection may be avoided.

Carbonic anhydrase IX (CAIX) is a hallmark of metabolic change in cancer cells. Enzyme-linked immunosorbent assay and immunocytochemistry methods for determination of CAIX protein are potential additional tests for detection of malignant pleural effusions.

The correlation between p16^INK4a immunoreactivity in urinary cytology and biopsies is reasonably strong. p16^INK4a may be useful in the diagnosis and follow-up of low-grade urothelial carcinomas in urine cytology.