Fine needle aspiration biopsy of the liver. Principal diagnostic challenges

Fine needle aspiration biopsy (FNAB) is the diagnostic procedure of choice for evaluation of liver lesions. Although primarily applied to malignant disease, it is also used in the evaluation of benign conditions. Improvements in imaging techniques and advances in cytologic interpretations, as well as production of new biopsy needles, have all contributed to the rapid increase in radiologically guided liver FNAB.

Aspiration cytology of malignant neoplasms associated with granulomas and granuloma-like features: diagnostic dilemmas

BACKGROUND

Malignant lymphomas and solid tumors that mimic or are associated with epithelioid granulomas are widely recognized in surgical pathology, but have received little attention in the cytopathology literature. In this study the authors present their experience with six such cases in which the presence of granulomas or granuloma-like features posed a diagnostic difficulty on fine-needle aspiration cytology (FNAC).

METHODS

Clinical data, FNAC, and follow-up surgical specimens from six patients presenting with neck masses were reviewed.

RESULTS

Only one case was diagnosed confidently as metastatic squamous cell carcinoma with an extensive granulomatous response; the other five were interpreted as "atypical" with descriptive cytology and a differential diagnoses including granulomatous inflammation, in addition to a caveat of "cannot exclude malignancy." Biopsy studies in these cases were recommended in view of the atypical cytologic findings and strong clinical suspicion of malignancy in each case. The histologic findings in two cases revealed Hodgkin's disease with exuberant granulomatous response. The remaining three cases were found to be malignant neoplasms with epithelioid morphologic features and included one example each of diffuse large cell lymphoma, anaplastic carcinoma of the thyroid, and lymphoepithelial carcinoma.

CONCLUSIONS

Malignancies associated with granulomas and tumor cells mimicking epithelioid histiocytes may be difficult to diagnose accurately on FNAC. The cytologic differential diagnosis of a "granulomatous" process should include malignant neoplasms. Excisional biopsy studies may be required for definitive diagnosis.

Diagnostic pitfalls of aspiration cytology of salivary duct carcinoma

BACKGROUND

Salivary duct carcinoma (SDC) is a highly aggressive primary salivary gland neoplasm that resembles intraductal and infiltrating breast carcinoma histologically. The purpose of this study was to review the cytologic features of histologically proven salivary duct carcinomas and to identify the potential pitfalls in cytologic diagnosis.

METHODS

Fine-needle aspiration cytology of nine histologically proven salivary duct carcinomas was reviewed.

RESULTS

The patients' age ranged from 62 to 89 years (median, 69 years). There were eight males and one female. The cytologic diagnoses of these cases were as follows: pleomorphic adenoma (PA) (three cases), high grade carcinoma, not otherwise specified (three cases), mucoepidermoid carcinoma (MEC) (two cases), and atypical cytology with differential diagnosis including MEC, oncocytoma, and acinic cell carcinoma (one case). The spectrum of cytologic findings included broad flat sheets and three-dimensional clusters. There was mild to severe cellular pleomorphism and nuclear atypia. Papillary clusters and cribriforming occasionally were identified. Bland cytologic features and prominent hyaline stroma, shown to represent the dense fibrosis on histologic sections, were identified in three cases cytologically interpreted as PA.

CONCLUSIONS

Fine-needle aspiration of SDC may be difficult to interpret accurately, and bland cytomorphologic features in some cases may lead to a false-negative interpretation; several clinically important pitfalls are demonstrated in our series.

The usefulness of the reticulin stain in the differential diagnosis of liver nodules on fine-needle aspiration biopsy cell block preparations

We reviewed fine-needle aspiration biopsy (FNAB) cell blocks of hepatocellular carcinoma (HCC) (n = 16) and benign hepatic processes (n = 16) to evaluate the significance of reticulin staining (Gomori stain) in combination with standard cytomorphologic and architectural criteria. We analyzed the staining pattern using semiquantitative grading: normal, variable, decreased, or virtually absent. Also, we graded the cell thickness of the hepatic trabeculae as greater than or less than three cells. Fourteen of 16 biopsy specimens of benign processes demonstrated a normal reticulin framework, with staining outlining hepatic trabeculae less than three cell layers in thickness. Staining was markedly decreased in one case of steatosis and virtually absent in one case of cirrhosis. In contrast, all of the 16 HCCs demonstrated either a virtually absent (7 of 16), decreased (6 of 16), or variable (3 of 16) reticulin staining pattern, with thickened trabeculae greater than three cell layers. We conclude that the reticulin stain is a useful adjunct in the differential diagnosis of liver nodules on FNAB cell block preparations and that it is particularly useful in distinguishing HCC from benign hepatic processes. Virtually absent or decreased reticulin staining and staining outlining trabeculae greater than three cells in thickness support the diagnosis of HCC. Normal reticulin staining outlining well-defined hepatic trabeculae less than three cell layers in thickness supports the diagnosis of a benign hepatic process.

Cytology of germ cell tumors: extragonadal, extracranial masses and intraoperative problems

BACKGROUND

Germ cell tumors (GCTs) and their metastases may be found in numerous sites that are accessible to cytologic sampling, and many are responsive to chemotherapy.

METHODS

The authors reviewed 20 examples of GCT cytology from 16 males and 3 females ranging in age from 1.5 to 61 years (median, 34 years). With two exceptions, one benign cystic ovarian teratoma in which intraoperative cytology was used to diagnose an associated adult-type carcinoma and one undescended testis in which seminoma presented as an abdominal mass, the material reviewed included no examples of primary gonadal GCT.

RESULTS

The authors studied 7 primary and 13 metastatic GCTs; these studies were based on 13 in vivo aspirations, 4 intraoperative preparations, and 3 samples of body cavity fluids. All samples were correctly interpreted as malignant, and only one was incorrectly classified as a non-GCT malignancy.

CONCLUSIONS

Clinical and cytologic findings are useful in the diagnosis of GCTs and their metastases. Incorrect interpretation of these neoplasms as poorly differentiated malignancies of other types may deprive the patient of effective chemotherapy. Air-dried, Romanowsky-stained smear material and cell block sections may contribute to the resolution of diagnostic dilemmas.

The vascular architecture of renal cell carcinoma in fine-needle aspiration biopsies. An aid in its distinction from hepatocellular carcinoma

BACKGROUND

The morphologic similarities between renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC) can cause diagnostic difficulty in fine-needle aspiration biopsy (FNAB) specimens. In the authors' prior study of liver FNAB, peripherally wrapping endothelium (PE) and arborizing transgressing endothelium (TE) were 100% specific for HCC relative to metastatic tumors, which included only three RCCs. In this study, the vascular patterns of RCC in FNAB were reviewed for comparison with HCC, to determine their usefulness in the differential diagnosis of HCC and RCC.

METHODS

FNAB of 49 RCCs (26 primary and 23 metastatic) from 46 patients were reviewed. Four vascular patterns were assessed: PE, TE, papillary endothelium (PAP) in fibrovascular cores of papillary fragments, and short nonbranching endothelium (SE) in small cell clusters. Each pattern was given a semiquantitative score: absent (0), focal (1), or extensive (2). Cellularity was categorized as low (< 20 groups), moderate (20-50 groups), or high (> 50 groups).

RESULTS

Vessels were present in 19 of 26 (73%) primary and 9 of 23 (39%) secondary RCC. PE was not identified. TE was observed in 11 primary (42%) and 7 metastatic (30%) RCC. SE was present in 5 primary (19%) and 1 metastatic (4%) RCC. The TE and SE patterns were distributed among the clear cell, granular cell, and chromophobe RCC. PAP was observed in all four papillary RCC. The majority of the TE and all of the PAP were present in moderately to highly cellular FNABs, whereas SE was usually observed in FNABs with low cellularity.

CONCLUSIONS

FNAB specimens of RCC commonly contain TE, as in HCC, but lack PE. TE was less frequent in metastatic than primary RCC. Other vascular patterns (SE, PAP), absent in HCC, were observed infrequently. Vascular patterns, especially PE, are useful in distinguishing HCC from RCC.

Cytopathologic touch preparations (imprints) from core needle biopsies: accuracy compared with that of fine-needle aspirates

OBJECTIVE

The aim of this study was to evaluate the touch preparation (imprint) cytology method for obtaining rapid interpretations from core material obtained during abdominal percutaneous biopsy.

SUBJECTS AND METHODS

For 28 patients undergoing biopsy of abdominal masses, paired slides were prepared for rapid staining by use of smears of standard fine-needle aspirates and by use of a touch preparation of the core material obtained with a semiautomated biopsy gun. The slides were scored in comparison with the final cytopathologic and histopathologic diagnosis.

RESULTS

Touch preparation slides were equivalent in diagnostic yield to fine-needle aspirate smears, demonstrating similar cellular features. Touch preparation slides revealed features of tumor architecture not present on smears.

CONCLUSION

Touch preparation cytology offers rapid diagnosis from a single core biopsy sample. Carefully performed, the touch preparation method preserves the core material for subsequent permanent fixation and sectioning.

Significance of endothelium in the fine-needle aspiration biopsy diagnosis of hepatocellular carcinoma

We reviewed fine-needle aspiration biopsies (FNAB) of hepatocellular carcinoma (HCC) (n = 35), benign hepatic processes (n = 35), cholangiocarcinoma (CC) (n = 6), and metastatic tumors (n = 100) to evaluate the significance of endothelium present either peripherally-wrapping around groups of cells, (peripheral endothelium (PE)), or transgressing sheets of cells (transgressing endothelium (TE)), in distinguishing these lesions. These patterns were assessed as absent, focal, or prominent. Thirty-three of 35 (94%) HCCs contained either focal or prominent PE or TE, compared to only 3 of 35 (9%) benign hepatocytic lesions. Only one benign lesion contained a prominent endothelial component (TE only). Two cases of HCC failed to contain endothelium, one fibrolamellar variant and one well-differentiated HCC. These differences were statistically significant (P < 10(-5), sensitivity 94%, specificity 91%, and positive predictive value [PPV] 92%). Neither pattern of endothelium was present in any CC or metastatic tumor. These differences were also statistically significant (P < 10(-5), sensitivity 94%, and specificity and PVP 100%). We conclude that the presence of endothelium, at least focally in either one or both distinctive patterns, is highly sensitive and specific for HCC and aides in distinguishing it from benign hepatocytic lesions, CC, and metastases.

Endometrioid carcinoma of the ovary and endometrium, oxyphilic cell type: a report of nine cases

Six endometrioid carcinomas of the ovary and three of the endometrium composed predominantly or entirely of large eosinophilic (oxyphilic) cells are reported. The ovarian tumors occurred in women 31-75 years of age, with a mean of 58 years, and the endometrial tumors occurred in women 37-50 years, with a mean of 44 years. All the ovarian tumors and one endometrial tumor contained focal areas typical of endometrioid carcinoma, with round to oval tubular glands lined by simple or stratified columnar cells and focal squamous differentiation. Two endometrial tumors were composed almost exclusively of oxyphilic cells lining glands. One endometrial tumor contained prominent luminal and intracytoplasmic mucin. Five of the ovarian tumors were grade 2/3 and one was grade 3/3, whereas two of the endometrial tumors were grade 1/3 and one was grade 2/3. The prominence of the oxyphilic cells posed diagnostic difficulty in most of the cases. Electron microscopic examination performed on all tumors showed abundant mitochondria in only one, an ovarian tumor. Other organelles, especially microfilaments and tonofibrils, are cited as other possible reasons for the eosinophilia. Four of the nine cases were recent; follow-up of the remaining five showed a biological behavior similar to the typical endometrioid carcinoma of the ovary and endometrium. We suggest that the diagnosis of "endometrioid carcinoma, oxyphilic cell type" is appropriate for this variant of carcinoma largely composed of eosinophilic cells that may or may not be "oncocytic" in nature. The importance of recognizing this entity lies in distinguishing it from diverse other primary and metastatic oxyphilic cell tumors of the ovary and eosinophilic cell metaplasia and rare other types of primary carcinoma with eosinophilic cells of the endometrium, which may be especially challenging in a curettage or biopsy specimen.

Benign metastasizing pleomorphic adenoma of salivary gland: diagnosis of bone lesions by fine-needle aspiration biopsy

Two cases of benign salivary gland pleomorphic adenomas metastatic to bone (benign-metastasizing pleomorphic adenomas) diagnosed by fine-needle aspiration biopsy are presented. Both primary tumors were slightly atypical cytologically but neither case demonstrated features of carcinoma. The metastatic lesions contained benign epithelial, myoepithelial, and stromal components. In both cases the clinical history was either not known by the radiologist or not communicated to the cytopathologist interpreting the case, and a primary tumor of bone was the leading clinical diagnosis. Obtaining pertinent clinical history and comparing the cytomorphology of the bone aspirate with the primary parotid tumor allowed for an accurate diagnosis in both cases. The differential diagnosis with primary bone tumors is discussed and the importance of clinical history is emphasized.

Clinical utility of fine needle aspiration biopsy in the diagnosis of Wegener's granulomatosis. A report of two cases

In two patients, pulmonary lesions of Wegener's granulomatosis (WG) were sampled by fine needle aspiration biopsy: one with the clinical diagnosis of primary pulmonary malignancy and the other with a clinical suspicion of WG. In the latter case the smears showed distinctive eosinophilic, collagen necrosis (pathergic necrosis), poorly formed granulomata composed of loose aggregates of elongated, often palisading epithelioid histiocytes, and multinucleate histiocytes. A cell block preparation in this case contained minute tissue fragments illustrating the distinctive, pathergic-type necrosis. In the former case, many of these features were present, but additionally there were several groups, atypical bronchial epithelial cells that, in light of the clinical impression, initially led to an incorrect diagnosis of bronchoalveolar carcinoma. Subsequent review of this case led to the diagnosis of WG. Antineutrophil cytoplasmic antibody (ANCA) serology was later obtained, confirming the diagnosis of WG in both cases. In our experience, the cytomorphologic findings of granular collagen necrosis, granulomata and multinucleate cells, although not specific, should alert the cytopathologist to consider the diagnosis of WG, especially when special stains for microorganisms are negative. A recommendation for ANCA serology testing early in the disease process, particularly in the limited forms of the disease, may lead to early recognition of WG, resulting in prompt institution of immunosuppressive therapy, greatly improving the patient's prognosis.

The use of fine-needle aspiration in the diagnosis of metastatic pulmonary adenoid cystic carcinoma

Nine patients with a history of adenoid cystic carcinoma (ACC) arising in the head and neck and in whom transthoracic fine-needle aspiration (FNA) was performed to investigate pulmonary lesions are described. FNA yielded a definitive diagnosis of metastatic ACC in all cases. In six of the nine patients, the pulmonary metastases were asymptomatic. Lung lesions were discovered up to 19 years after primary tumor presentation, and in two, pulmonary spread was the only evidence of recurrent disease. On the basis of the FNA diagnosis, these two patients were treated surgically for their isolated pulmonary metastases, and are disease free at 107 and 139 months. Six of the nine patients received radiation or chemotherapy; one initially refused treatment. Thoracotomy was avoided in these patients on the basis of the FNA diagnosis. All are alive with disease at 25 to 246 months. The metastatic tumors were indistinguishable cytologically from two primary pulmonary ACCs that were available for comparison. Our experience suggests FNA is a useful tool in the diagnosis of ACC in pulmonary material--one which obviates the need for thoracotomy with its associated morbidity.