Angiomatoid fibrous histiocytoma: novel MR imaging findings.

OBJECTIVE: To describe novel MR imaging features, and clinical characteristics of soft tissue angiomatoid fibrous histiocytoma (AFH) at presentation, local recurrence, and metastases. MATERIALS AND METHODS: We described the MRI findings of six cases of histologically proven AFH. Pathologic findings, clinical presentation, and outcome were reviewed. RESULTS: Lesions were primarily cystic. At initial presentation, tumors were surrounded by low signal intensity fibrous pseudocapsule. High signal intensity consistent with the lymphoplasmacytic infiltrate was seen in T2-weighted and post-contrast images as a rim over the hypointense pseudocapsule (double rim sign). High signal intensity infiltrating tumoral cords extended into adjacent tissues, through pseudocapsular defects on T2-weighted and post-contrast images. The cystic component and tumor cell nodularity were demonstrated at post-contrast images. Clinically, lesions were often thought to be benign, underwent marginal resection, developed local recurrence, and one developed second recurrence consisting of metastases. Recurrent tumors appeared as multiple masses, misinterpreted as post-surgical changes. An intramuscular recurrence demonstrated double rim and infiltrating margin. CONCLUSIONS: A predominantly well-circumscribed, primarily cystic mass with double-rim and marginal infiltration on MRI suggests the possibility of AFH, in particular in child or young adult. Inclusion of these novel observations in AFH differential diagnosis may have a significant impact on treatment and prevention of recurrence.

Needle biopsy of mesenchymal lesions of the head and neck: Evolving concepts and new strategies for diagnosis.

Sarcomas are a rare and heterogeneous group of neoplasms that can be a significant diagnostic challenge in routine practice. Recent advances in the understanding of molecular mechanisms underlying oncogenesis have led to an array of novel diagnostic tools. Here we review several sarcomas of the head and neck region, focusing on neoplasms with new molecular findings and highlighting novel diagnostic tools.

Imaging of recurrent intramuscular granulomatous masses induced by depot injection of leuprorelin.

Leuprorelin is a luteinizing hormone-releasing hormone (LH-RH) agonist that is used as an agent of androgen deprivation in some patients with prostate cancer. When administered in depot form, local granulomatous reactions may occur at the injection site, which may mimic masses and which are associated with treatment failure. We present a patient who, over a period of 5 years, developed multiple intramuscular gluteal masses while receiving leuprorelin therapy via intramuscular depot injections; biopsy of one of the masses showed the specific histologic features of leuprorelin granuloma. To our knowledge, this entity has not been described in the radiology literature. Awareness of this entity is necessary to suggest the correct diagnosis in patients with a history of leuprorelin depot injections.

Pseudotear of the peroneus longus tendon on MRI, secondary to a fibrocartilaginous node.

OBJECTIVE: The purpose of this study was to identify the presence of a fibrocartilaginous node within the distal peroneus longus tendon (PLT) just proximal to the cubital tunnel and correlate this with MRI signal characteristics of the distal PLT, which could result in a pseudotear appearance on MRI. We correlated imaging characteristics with pathologic specimens. MATERIALS AND METHODS: Institutional review board approval was obtained. Retrospectively, 91 ankle MRIs utilizing a standard ankle protocol were reviewed by two musculoskeletal radiologists. Four cadaver ankles were imaged using a standard ankle MRI protocol and reviewed by the same radiologists. All the MRIs were examined for signal changes in the PLT. The cadaver ankles then underwent PLT dissection by an orthopaedic surgeon, and a pathologic review was undertaken by a pathologist with orthopaedic specialization, who looked for an os peroneum or proposed fibrocartilaginous node relating to the signal change found on the MRIs. RESULTS: In the 91 ankle MRI studies, the PLT demonstrated normal low and increased signals. On the fat-saturated T2-weighted sequence, 76 (83.5%) ankles demonstrated low signal and 15 (16.5%) demonstrated increased signal. Of the cadaver ankle MRIs, all four demonstrated increased signal within the PLT; three contained a fibrocartilaginous node and one contained an os peroneum in that same region. CONCLUSIONS: The MRI signal of the PLT can change with the presence of a fibrocartilaginous node, which may be due to the molecular and chemical content of the fibrocartilage. This node increases the MRI signal in the distal PLT and gives the appearance of a pseudotear.

Leiomyosarcoma of the somatic soft tissues.

Leiomyosarcomas of the somatic soft tissues are tumors of smooth muscle origin that occur in the extremities. These lesions are commonly high-grade tumors that carry a poor prognosis. Recommended treatment often includes wide excision and chemotherapy or radiation therapy. Sixty-five patients were followed for a mean of 4.1 years. The mean maximum tumor diameter was 7 cm, and approximately 70% of all patients had tumors deep to fascia. Including all stages of disease, the overall 1-, 2-, and 5-year survival rates were 91%, 87%, and 68%, respectively. Mitotic rate and tumor depth were significant predictors of development of recurrent disease and metastatic disease. Tumor size was another predictor of recurrent disease. The mitotic rate and AJCC stage were also important predictors of overall survival. Patients with deep lesions, histologic grade 3 disease/higher mitotic rates, and advanced stage of disease had a poorer prognosis and thus were more likely to undergo adjuvant chemotherapy. Future clinical studies may help determine if knowledge of these predictors can help guide treatment and improve clinical outcomes.

Crystals and crystalloids in cytopathology: Incidence and importance.

Many crystals and crystal-like structures may be encountered in cytopathology practice and can represent both beautiful novelties and diagnostic aids. The authors present an organ-specific review of the published literature on crystals combined with personal experiences. The purpose is not only to serve as a reference guide by highlighting the clinical and morphologic features of crystals, crystalloids, and crystal-like structures but also to review their significance and to offer reporting strategies in cases that bear management implications.

Performance of specific morphologic features in distinguishing low-grade squamous intraepithelial lesions from high-grade squamous intraepithelial lesions in borderline cases: a College of American Pathologists Cytopathology Committee multiobserver study.

INTRODUCTION: Distinguishing between low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) can be difficult on certain Papanicolaou (Pap) tests, hindering interobserver concordance. We investigated the variables influencing the interpretation of LSIL versus HSIL in Pap test slides rejected from the College of American Pathologists PAP education program. MATERIALS AND METHODS: Eleven cytologists, who were unaware of the reference interpretation, examined 21 Pap slides (11 submitted as LSIL and 10 as HSIL) rejected from the PAP education program and recorded the number of LSIL cells, HSIL cells, keratinized dysplastic cells, LSIL clusters with mixed HSIL cells, atypical squamous metaplasia, atypical glandular cells, the presence of inflammation or infectious organisms, and the overall interpretation (LSIL or HSIL). We evaluated the significance of these 11 variables using a nonlinear mixed model analysis. RESULTS: LSIL had greater concordance (92 of 121 responses; 76.0% concordance) than HSIL (68 of 110 responses; 61.8% concordance; P < 0.001). The only predictors of misclassified cases were the number of atypical squamous metaplastic cells and the number of HSIL cells (P < 0.001). The more of these cells identified, the more likely the reviewers were to classify the slide as HSIL. The reproducibility of the diagnosis was fair (Gwet's agreement coefficient, 0.33). CONCLUSIONS: Interobserver reproducibility is a challenge for a subset of cases with features intermediate between LSIL and HSIL. Atypical squamous metaplasia and dysplastic nuclei with a nuclear/cytoplasmic ratio greater than one half of the cell volume (HSIL) present on a Pap test influenced the likelihood that a reviewer would interpret the case as HSIL rather than LSIL.

Case report: lead toxicity associated with an extra-articular retained missile 14 years after injury.

Lead toxicity associated with extra-articular retained missiles (EARMs) is an uncommon yet potentially devastating complication of gunshot wounds. While the risk of lead toxicity with intra-articular retained missiles is well-known, EARMs are routinely permitted to remain in tissues indefinitely without surveillance for lead toxicity. We present a 34 year-old man who was found to have symptomatic lead toxicity 14 years after sustaining a gunshot-associated femoral fracture with retention of lead bullet fragments. A fluid-filled cyst containing two large lead bullet fragments was identified intraoperatively. Whole-blood lead concentration decreased after removal of the lead-filled cyst. Cyst formation and concomitant bone fracture are two of the risk factors for lead toxicity in patients with EARMs after gunshot wounds. Recognizing risk factors for EARM-associated elevation in lead levels is important as the adverse effects of increased lead burden may be asymptomatic and difficult to diagnose, yet debilitating and potentially lethal.

Making the diagnosis of acute appendicitis: do more preoperative CT scans mean fewer negative appendectomies? A 10-year study.

PURPOSE: To determine the frequency of preoperative computed tomography (CT) in the evaluation of patients suspected of having appendicitis at one institution during the past 10 years and to determine whether changes in CT utilization were associated with changes in the negative appendectomy rate. MATERIALS AND METHODS: Institutional review board approval was obtained, and a waiver of informed consent was granted for this HIPAA-compliant study. A surgical database search yielded medical record numbers of 925 patients (526 [ 56.9%] men and 399 [43.1%] women; mean age, 38 years (range, 18-95 years]) who underwent urgent appendectomy between January 1998 and September 2007. Patients who were younger than 18 years of age at the time of surgery were excluded. CT, pathology, and surgery reports were reviewed. By using logistic regression, changes in the proportion of patients undergoing CT and in the proportion of patients undergoing each year appendectomy in which the appendix was healthy were evaluated. Subgroup analyses based on patient age ( 45 years) and sex also were performed. RESULTS: Prior to urgent appendectomy, 18.5% of patients underwent preoperative CT in 1998 compared with 93.2% of patients in 2007. The negative appendectomy rate for women 45 years of age and younger decreased from 42.9% in 1998% to 7.1% in 2007. However, the timing of the decline in negative appendectomy rates for women 45 years and younger could not be proved to be associated with the increase in CT use. There was no significant trend toward a lower negative appendectomy rate for men regardless of age or for women older than 45 years of age with increased use of preoperative CT. The shift from single-detector CT to multidetector CT and the use of decreasing section thickness also correlated with a reduction in false-positive diagnoses. CONCLUSION: Rising utilization of preoperative CT and advances in technology coincided with a decrease in the negative appendectomy rate for women 45 years and younger but not in men of any age or women older than 45 years.

Carcinoid tumors of the appendix: are these tumors identifiable prospectively on preoperative CT?

The purpose of this study was to determine if carcinoid tumors of the appendix were identified prospectively on preoperative CT at our institution during the last decade. A surgical database search performed using the Current Procedural Terminology codes for appendectomy and colectomy yielded 2108 patients who underwent appendectomy or colectomy with removal of the appendix from January 1998 through September 2007. Pathology reports were reviewed to identify patients in whom an appendiceal carcinoid tumor was identified. Preoperative CT reports and images were reviewed. Twenty-three carcinoid tumors (1.1%; 15 women [65.2%], eight men [34.8%]; average age 54 years [range, 23 to 86 years]) were identified. Ten patients underwent preoperative CT. No tumors were identified prospectively on CT. Images were available for rereview for eight patients. Studies were acquired with 16- (n = 7) and four- (n = 1) slice CT scanners. Average reported tumor size was 6.1 mm (range, 1.5 to 15 mm; n = 18). A tip or distal location was reported for all tumors for which a location was given (n = 15). Carcinoid tumors occurred in 1.1 per cent of appendix specimens. These tumors were all less than or 1.5 cm in size. Likely as a result of their small size, none of these tumors was identified prospectively on preoperative CT.

Incidence and clinical relevance of non-small cell lung cancer lymph node micro-metastasis detected by staging endobronchial ultrasound-guided transbronchial needle aspiration.

BACKGROUND: Approximately twenty percent of lymph node (LN) negative non-small cell lung cancer (NSCLC) patients who undergo curative intent surgery have pan-cytokeratin immunohistochemistry (IHC)-detectable occult micro-metastases (MMs) in resected LNs. The presence of the MMs in NSCLC is associated worsened outcomes. As a substantial proportion of NSCLC LN staging is conducted using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), we sought to determine the frequency of detection of occult MMs in EBUS-TBNA specimens and to evaluate the impact of MMs on progression-free and overall survival. METHODS: We performed retrospective IHC staining for pan-cytokeratin of EBUS-TBNA specimens previously deemed negative by a cytopathologist based on conventional hematoxylin and eosin staining. The results were correlated with clinical variables, including survival outcomes. RESULTS: Of 887 patients screened, 44 patients were identified meeting inclusion criteria with sufficient additional tissue for testing. With respect to the time of the EBUS-TBNA procedure, 52% of patients were clinical stage I, 34% clinical stage II, and clinical 14% stage IIIa NSCLC. Three patients (6.8%) were found to have cytokeratin positive MMs. All 3 MMs detected were at N2 LN stations. The presence of MMs was associated with significantly decreased progression-free (median 210 vs. 1,293 days, P=0.0093) and overall survival (median 239 vs. 1,120 days, P=0.0357). CONCLUSIONS: Occult LN MMs can be detected in EBUS-TBNA specimens obtained during staging examinations and are associated with poor clinical outcomes. If prospectively confirmed, these results have significant implications for EBUS-TBNA specimen analyses and possibly for the NSCLC staging paradigm.

Low-Grade Squamous Intraepithelial Lesion or High-Grade Squamous Intraepithelial Lesion? Concordance Between the Interpretation of Low-Grade Squamous Intraepithelial Lesion and High-Grade Squamous Intraepithelial Lesion in Papanicolaou Tests: Results From the College of American Pathologists PAP Education Program.

CONTEXT.­: Obtaining diagnostic concordance for squamous intraepithelial lesions in cytology can be challenging. OBJECTIVE.­: To determine diagnostic concordance for biopsy-proven low-grade squamous intraepithelial lesion (LSIL) and high-grade squamous intraepithelial lesion (HSIL) Papanicolaou test slides in the College of American Pathologists PAP Education program. DESIGN.­: We analyzed 121 059 responses from 4251 LSIL and HSIL slides for the interval 2004 to 2013 using a nonlinear mixed-model fit for reference diagnosis, preparation type, and participant type. We evaluated interactions between the reference diagnosis and the other 2 factors in addition to a repeated-measures component to adjust for slide-specific performance. RESULTS.­: There was a statistically significant difference between misclassification of LSIL (2.4%; 1384 of 57 664) and HSIL (4.4%; 2762 of 63 395). There was no performance difference between pathologists and cytotechnologists for LSIL, but cytotechnologists had a significantly higher HSIL misclassification rate than pathologists (5.5%; 1437 of 27 534 versus 4.0%; 1032 of 25 630; P = .01), and both were more likely to misrepresent HSIL as LSIL ( P < .001) than the reverse. ThinPrep LSIL slides were more likely to be misclassified as HSIL (2.4%; 920 of 38 582) than SurePath LSIL slides (1.5%; 198 of 13 196), but conventional slides were the most likely to be misclassified in both categories (4.5%; 266 of 5886 for LSIL, and 6.5%; 573 of 8825 for HSIL). CONCLUSIONS.­: More participants undercalled HSIL as LSIL (false-negative) than overcalled LSIL as HSIL (false-positive) in the PAP Education program, with conventional slides more likely to be misclassified than ThinPrep or SurePath slides. Pathologists and cytotechnologists classify LSIL equally well, but cytotechnologists are significantly more likely to undercall HSIL as LSIL than are pathologists.

Fine-needle aspiration of fibrous dysplasia of bone: a worthwhile endeavor or not?

Fine-needle aspiration (FNA) is a minimally invasive technique which is enjoying ever-increasing popularity in the initial diagnosis of many pathologic processes. However, FNA diagnosis of neoplasms occurring within bones is less commonly employed and is not the preferred method in some types of bony lesions. Fibrous dysplasia is a primary neoplasm of bone for which it is not yet clear whether FNA can reliably yield adequate diagnostic material. Review of data from 82 cases of fibrous dysplasia diagnosed between 1990 and 2006 yielded six cases, in which diagnosis was initially attempted by FNA prior to open biopsy and surgical resection. Corresponding cytologic, histologic, and imaging characteristics of the cases were reviewed. Of the six cases in which initial diagnosis was attempted by FNA, only two of six (33%) yielded adequate diagnostic material. Smears of aspirated material in all cases contained nonspecific elements, including fragments of benign host bone and cartilage, bland stromal cells, adipocytes, blood, and debris. Importantly, the two positive FNA cases were dependent on the concurrent core needle biopsy (all smears of aspirate material were nondiagnostic). Even with image guidance, FNA is insufficient to obtain diagnostic material for cases of suspected fibrous dysplasia of bone. Core needle biopsy at least is recommended to obtain adequate material, and to reduce the risk of misdiagnosis due to sampling error.

CIC-DUX4 sarcoma diagnosed by fine-needle aspiration cytology: A case report.

The CIC-DUX4 sarcoma is a small round blue cell sarcoma which presents like extraskeletal Ewing sarcoma, but is negative for the EWSR1 gene translocation. The recognition of CIC-DUX4 sarcomas as an aggressive sarcoma may be challenging in fine needle aspirates or small needle core biopsies. We present a case of a 13-year-old female with a fine needle aspiration (FNA) and core needle biopsy (CNB) of a thigh mass showing CIC-DUX4 sarcoma. Cytologic findings include tumor cells with high nuclear to cytoplasmic (N:C) ratio, eccentric nuclei and small nucleoli. The tumor cells were arranged in sheets and singly dispersed with background necrosis. Mitotic figures and apoptosis were present. These findings are similar to cases previously reported. Other reported findings of spindled nuclei, clear cell change and lobular growth pattern were not seen in our case. Immunohistochemical stains showed tumor cells positive for CD99, WT1, vimentin and negative for pancytokeratin, desmin and myogenin, which is the pattern similar to cases previously reported. However, our case was also positive for BCL-2. Fluorescence in situ hybridization (FISH) was negative for EWSR1 and SS18 (SYT) rearrangements and positive for CIC gene rearrangement. On balance, if the following features are seen: (1) a small round blue cell tumor with histomorphology more atypical than that of Ewing sarcoma, (2) cytoplasmic CD99 staining, nuclear WT1 positivity, negative keratin, desmin and myogenin; and (3) EWSR1 rearrangement negative by FISH, then molecular testing for CIC-DUX4 sarcoma should be considered.

Intraosseous Rosai-Dorfman disease diagnosed by touch imprint cytology evaluation: A case series.

Sinus histiocytosis with massive lymphadenopathy, also known as Rosai-Dorfman disease (RDD) is a rare benign disorder that primarily affects the lymph nodes. Localized lymphadenopathy is the most common clinical manifestation of this disorder. However, RDD has been described in several extra-nodal sites including the head and neck region, soft tissue, skin, upper respiratory tract, gastro-intestinal tract and central nervous system (CNS). Involvement of the bone is considered very rare, occurring in less than 10% patients. RDD is one of the histiocytoses and the differential diagnosis includes entities such as Langerhans cell histiocytosis and Erdheim-Chester disease. In the rare intraosseous variant, the clinical and radiologic differential diagnosis is broader and includes neoplasms such as osteosarcoma and Ewing sarcoma. In this report, we describe three cases of extra-nodal, intraosseous RDD where touch imprint cytology played a crucial role in diagnosis. Two of the cases initially presented with involvement of the head and neck region and later developed intraosseous disease; while the third patient presented with primary bone involvement. The diagnosis was established by core biopsy with touch imprints of the bone lesions. The cytologic samples showed numerous histiocytes, often with neutrophils within their cytoplasm (emperipolesis) in addition to lymphocytes and plasma cells. The diagnosis of RDD was confirmed with appropriate immunohistochemical stains. Our account of these three cases of intraosseous Rosai-Dorfman disease highlights the role of cytology in the diagnosis of this rare entity.

Northern Italy in the American South: Assessing interobserver reliability within the Milan System for Reporting Salivary Gland Cytopathology.

BACKGROUND: The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has been proposed to standardize salivary gland fine-needle aspiration (FNA) diagnoses. This study assessed salivary gland FNA results and risk of malignancy (ROM) rates at the University of North Carolina as well as the interobserver reliability (IOR) of the atypia of undetermined significance (AUS) and salivary gland neoplasm of uncertain malignant potential (SUMP) categories. METHODS: The electronic medical record was searched for FNA cases from 2010 to 2017 with subsequent surgical resections. Histologic diagnosis was used for gold-standard comparison. The original cytologic results were then converted into MSRSGC categories (nondiagnostic, nonneoplastic, AUS, benign neoplasm, SUMP, suspicious, and malignant). For the assessment of IOR, 23 cases were selected with enrichment for cases diagnosed as AUS (n = 11) or SUMP (n = 9). Six boarded cytopathologists and 1 cytopathology fellow assessed representative slides and provided an MSRSGC diagnosis for each case. Fleiss' κ coefficients were calculated to determine IOR. RESULTS: The ROM was 33% for both AUS and SUMP cases; however, the risk of neoplasia was 56% for AUS cases and 100% for SUMP cases. Fleiss' κ for the AUS category was 0.217 (P < .05), and Fleiss' κ for the SUMP category was 0.024 (P = .74). CONCLUSIONS: In this study assessing the IOR of MSRSGC categories, fair agreement and slight agreement were found for the AUS and SUMP categories, respectively. Observers preferentially used the AUS or benign neoplasm category for SUMP cases, perhaps because of unfamiliarity with SUMP as a diagnostic option. The initial adoption of a new reporting system will require a quality assessment to ensure that the system is reliable and useful for clinicians. Cancer Cytopathol 2018;126:390-6. © 2018 American Cancer Society.

Acral myxoinflammatory fibroblastic sarcomas: MRI findings in four cases.

OBJECTIVE: Acral myxoinflammatory fibroblastic sarcoma is a rare, recently described, low-grade sarcoma that involves mainly the distal extremities. The purpose of this study is to report the MRI findings in four cases of acral myxoinflammatory fibroblastic sarcoma. CONCLUSION: Acral myxoinflammatory fibroblastic sarcomas may present with various MRI patterns that probably reflect their variable histologic composition. Differential diagnosis with other benign conditions, especially with ganglion cysts and giant cell tumors of the tendon sheath, may be difficult. We report tumoral invasion of the bone in one case, which to our knowledge has not been previously described.

Desmoplastic small round cell tumor: using FISH as an ancillary technique to support cytologic diagnosis in an unusual case.

Desmoplastic small round cell tumor is a rare and aggressive neoplasm that predominantly affects young males. In almost all cases, a reciprocal translocation is present resulting in the fusion of the Ewing sarcoma gene with the Wilms' tumor gene. Here we describe an unusual case occurring in a 59-year-old male, in which fluorescence in situ hybridization (FISH) was used in conjunction with immunohistochemical studies to confirm the diagnosis. To our knowledge, this is the first reported case of using FISH as an ancillary technique to confirm the cytologic diagnosis of this tumor.

Fine-needle aspiration of chondrosarcoma.

Fine-needle aspiration (FNA) is a reliable, safe and cost-effective procedure with an established role in the diagnosis of various solid tissue neoplasms. However, the role of FNA in the diagnosis of primary bone tumors, including chondrosarcoma (CS) is controversial. To determine the accuracy of FNA as a diagnostic procedure, the author reviewed the institutional experience of a series of patients with CS who underwent FNA for diagnosis. The author's objectives were to determine the accuracy of the technique as well as possible limitations to sensitivity and specificity, and perhaps to suggest the most appropriate use for this procedure. Computer records and then subsequently archives of the department were searched for patients diagnosed and treated for CS between 1993 and 2003. Patients without adequate clinical follow-up, missing materials or records otherwise unavailable for review were eliminated from study. All patients who underwent FNA for a diagnosis had to have a subsequent histological confirmation to be included in the study. FNAs were largely performed with image-guided assistance. In those that were palpable, the aspiration was performed by the aspiration cytologist using standard methods. Histologic materials were processed according to standard methods. All cytological and histologic materials were reviewed for accuracy and appropriateness of diagnosis by the author. There were 34 aspirates from 32 patients with CS (2 patients with 2 aspirates each). Attempts at diagnoses were made from 27 primary lesions, 6 recurrent lesions, and one metastatic lesion. There were an additional two patients who were assigned a diagnosis of CS on FNA who ultimately were proven to have chondroblastic osteosarcoma. Of the primary CS, 18 were definitively diagnosed as CS or "malignant chondroid neoplasm," 8 of the aspirates were considered equivocal in that an additional diagnostic procedure was required to clarify or confirm the diagnosis. Two aspirates were diagnosed as negative. Both of the false negatives were due to inadequate sampling of the lesion on FNA. Diagnostic accuracy of FNA for primary CS in this series was 67% (18/27). Accuracy for recurrent or metastatic lesions was higher at 86% (6/7). FNA appears to be a reliable means of diagnosis of recurrent and/or metastatic CS in patients with a documented history. In primary lesions, however, the accuracy of the technique is lower. In addition, there are problems of sampling chondroid components of non-CS lesions such as this study's experience with chondroblastic osteosarcoma.

Cytomorphology of yolk sac tumor of the liver in fine-needle aspiration: a pediatric case.

Yolk sac tumors (YST) in extragonadal locations are rare. Cytologic diagnosis of YST on fine-needle aspiration (FNA) smears may be a challenge to the cytopathologist. Further neo-adjuvant therapy may be based on cytologic diagnosis making accuracy important. We studied FNA material from a hepatic mass in a pediatric patient to further define the cytomorphologic features of hepatic YST. Features include large pleomorphic balls of tumor cells with high nuclear to cytoplasmic ratios, papillary or microglandular pattern of growth, cytoplasmic and intranuclear vacuoles, and prominent nucleoli. Positive immunohistochemical studies included alpha-fetoprotein, cytokeratin AE1/AE3, and CAM 5.2, which are useful in supporting the diagnosis. We report a pediatric patient in whom the diagnosis of hepatic YST was made by cytologic, histologic, and immunohistochemical studies. The subsequent liver biopsy was consistent with the FNA diagnosis. Our findings may further help to characterize the cytomorphologic features of this rare lesion.