Cytologic differential diagnosis of papillary pattern in breast aspirates: correlation with histology.

Papillary neoplasms, fibroadenoma, fibrocystic change, low-grade ductal carcinoma, and apocrine carcinoma are among "gray zone" lesions in breast cytology. They often have cellular smears with a papillary or pseudopapillary pattern. To better define cytologic criteria useful in distinguishing these entities, we correlated them with histology. Papanicolaou and giemsa stained smears from 33 aspirates and their corresponding histology were reviewed. Of these, 28 had an initial cytologic diagnosis or suspicion of papillary neoplasm, while five cases were not diagnosed cytologically as papillary but the histologic diagnosis was a papillary neoplasm. Cytologic features evaluated included cellularity, architecture, apocrine/single/columnar cells, nuclear atypia, intranuclear inclusions, calcifications, background, myoepithelial cells, and bipolar, naked nuclei. Discriminating cytologic features grouped by final histologic diagnosis were as follows: Papillary neoplasm (14 cases): Hemorrhagic/cystic background, 3-dimensional papillary clusters, columnar cells, and fibrovascular cores. Myoepithelial cells within clusters and background naked, bipolar nuclei were inconspicuous. Fibroadenoma (4 cases): Two-dimensional branching clusters often with folding, moderate myoepithelial cells in clusters, moderate to numerous background bipolar nuclei, often forming doublets in smear background, cellular stroma. Ductal carcinoma (11 cases): Papillary ductal carcinoma in situ in 5 of 11 cases, cribriform/tubular architecture in 6 of 11. Absence or paucity of myoepithelial within clusters and background bipolar nuclei was noted. Fibrocystic change (4 cases): Two-dimensional clusters, moderate myoepithelial cells within clusters, and moderate bipolar nuclei in the background. The presence and quantity of myoepithelial cells, bipolar naked nuclei in the background, and ductal cell architecture were the only consistently useful cytologic features in distinguishing breast lesions with a papillary pattern. Ann Diagn Pathol 5:34-42, 2001.

Thyroid plasmacytoma mimicking medullary carcinoma: a potential pitfall in aspiration cytology.

Extramedullary plasmacytoma (EMP), a malignant neoplasm of the soft tissues composed of plasma cells, may occur either as a solitary plasma-cell tumor (primary EMP) or as a manifestation of multiple myeloma (secondary EMP). We report on the aspiration cytology findings of an intriguing case of EMP of the thyroid that was initially misinterpreted as medullary carcinoma on clinical and cytologic examination. A major contributing cause for the cytologic misinterpretation was the presence of amyloid in the aspirate and the clinical impression of a "thyroid mass." Based on this experience, we suggest that EMP should be considered in the differential diagnosis of a neck mass that yields discohesive cells associated with amyloid/amyloid-like material. Clinical correlation and immunocytochemistry are crucial in avoiding pitfalls in this situation.

Hyaline globules in renal cell carcinoma and hepatocellular carcinoma. A clue or a diagnostic pitfall on fine-needle aspiration?

The cytologic similarity to hepatocellular carcinoma (HCC) of 2 cases of granular renal cell carcinoma (RCC) with hyaline globules (HGs) prompted us to evaluate the frequency of HGs in RCC and HCC and the association between cell type, differentiation, and malignant potential of these 2 neoplasms and the presence of HGs. We studied fine-needle aspirates from 23 cases of RCC (primary, 7; metastatic, 16) and 23 cases of primary HCC and noted anatomic site, tumor cell type, and presence, quality, and quantity of HGs. Fuhrman nuclear grade was assigned to RCC and overall differentiation to HCC cases. RCC cell type was granular (7), mixed (4), and clear (12). HCC cases were granular (22) and clear (1). Morphologically similar, predominantly intracytoplasmic HGs were identified in 4 RCCs and 10 HCCs. All 4 RCCs with HGs were at metastatic sites, granular cell type, and high Fuhrman grade. HGs showed no association with differentiation of HCC. While HGs are seen more commonly in HCC than in RCC, their presence in an adenocarcinoma should bring renal origin into consideration. The presence of HGs in metastatic granular RCC, particularly in the liver, can lead to misinterpretation as primary HCC.

Hemangiopericytoma of the liver: immunohistochemical observations, expression of angiogenic factors, and review of the literature.

PURPOSE: We describe an unusual case of a hemangiopericytoma in the liver of a child, review the literature, and characterize the tumor by immunohistochemistry and electron microscopy. We study the expression of basic fibroblast growth factor (bFGF) and of vascular endothelial growth factor (VEGF) in the tumor. MATERIALS AND METHODS: Clinical history and pathology were reviewed; sections of the tumor were studied by histology, electron microscopy, and immunohistochemistry using antibodies directed towards factor-XIIIa, HAM-56, bFGF and VEGF, among others. RESULTS: The expression of VEGF resembled that of "proliferating" hemangiomas; however, despite being markedly elevated in the urine, bFGF could not be unequivocally detected in the tumor. A subpopulation of factor XIIIa positive cells was identified, similar to the "interstitial" cells of the cellular hemangiomas of infancy. The nature and function of these cells remains speculative. CONCLUSIONS: Hemangiopericytomas are rare in the liver. When arising in this location in a child, they may clinically resemble a hemangioma, may express angiogenic factors in a similar fashion, and should be considered in the differential diagnosis.

Characterization of an evolutionarily old human alphoid DNA.

A recently isolated human alphoid DNA (in plasmid pHH550) has been sequenced and found to have an exceptionally high degree of similarity to the human alphoid consensus sequence, while its component monomers are unusually heterogeneous in sequence. In contrast to other alphoid DNAs, this DNA is found in all primates tested. Thus this may be an evolutionarily old sequence similar to the one from which other human alphoid DNAs diverged. The pHH550 sequences are found on a number of human chromosomes, including 21 and 22. On chromosome 21 most members of this new sequence group are located distal to other alphoid DNAs.