Diagnostic accuracy of image-guided percutaneous fine needle aspiration biopsy of the mediastinum

Interpreting a fine needle aspiration biopsy (FNAB) from the mediastinum is challenging as this location may harbor many lesions, including primary and metastatic tumors. Image-guided transthoracic (percutaneous) FNAB is less invasive than mediastinoscopy or endoscopic-guided FNAB. The aim of this study was to determine the diagnostic accuracy of FNAB performed percutaneously for evaluating mediastinal lesions.A retrospective study of 157 consecutive CT-guided transthoracic FNAB of the mediastinum was performed (1988-2004). Direct smears (N = 145; average 13 slides/case), ThinPrep slides (N = 25), and adequate cell blocks (N = 131) were prepared from procured cytologic material. When needed, ancillary studies included immunocytochemistry (N = 53) and flow cytometry (N = 8). Subsequent histologic tissue diagnoses available for 68 cases were also reviewed.Patients were of average age 57 yr (range 1-88 yr), including 75 males and 82 females. A definitive diagnosis was rendered in 128 (82%) cases. Primary neoplasms (N = 38) included 24 lymphomas (6 Hodgkin and 18 non-Hodgkin), 7 thymomas, 1 thymic carcinoma, and 6 peripheral nerve sheath tumors. Metastases (N = 72) were mainly carcinomas (N = 71) and 1 melanoma. There were 4 non-neoplastic lesions (1 granulomatous process; 2 bronchogenic and 1 pericardial cyst), 1 case of undifferentiated malignant large cell neoplasm, 13 cases negative for malignancy, and 29 (18%) that were indeterminate, due largely to insufficient cellularity. Subsequent histologic diagnoses were concordant with FNAB diagnoses in 53/68 cases (78%). Nine FNAB were inadequate/nondiagnostic. There were 6 discordant cases, including 5 FNAB that were of adequate cellularity but interpreted as negative for malignant cells (on subsequent histology 2 turned out to be Hodgkin lymphoma, 2 carcinomas, and 1 diffuse large cell lymphoma), and 1 diagnosed as thymoma that on histologic evaluation was a thymic large cell lymphoma.Adequate diagnostic cytologic material was obtained by image-guided percutaneous FNAB of mediastinal lesions in 82% of our cases. Sufficient material was available to make cell blocks and perform ancillary studies when necessary. These data also show a high proportion of agreement (78%) between FNAB and subsequent histologic diagnoses for a wide variety of mediastinal lesions. The majority of discordant cases were primarily interpretive, with a final cytologic diagnosis negative for malignancy. Only one problematic case misdiagnosed on FNAB as thymoma was found on subsequent surgical excision to be a thymic large B cell lymphoma. Cases with nondefinitive FNAB diagnoses were largely due to sampling error and/or insufficient cellularity. Therefore, percutaneous FNAB of the mediastinum is a diagnostically helpful, minimally invasive procedure that can be performed in patients of all ages as part of the evaluation of a mediastinal mass lesion.     

Concomitant lymphoma and metastatic carcinoma in a lymph node: Diagnosis by fine-needle aspiration biopsy in two cases

Concomitant lymphoma and metastatic carcinoma are an unusual occurrence in a lymph node. We report two patients in whom synchronous malignancies were diagnosed by fine-needle aspiration biopsy (FNAB). In one case, the FNAB diagnoses of both small lymphocytic lymphoma and metastatic breast carcinoma were the initial diagnoses. In the second case, metastatic poorly differentiated squamous carcinoma was an unexpected finding in a patient with a history of small lymphocytic lymphoma. The aspirates in both cases showed two distinct cell populations, one consisting of a dispersed population of small uniform lymphoid cells and the other comprising large atypical single cells and cohesive clusters of epithelial cells. In both cases, the cytologic diagnoses were supported by immunohistochemical and flow cytometric studies. Diagn. Cytopathol. 1997;17:287–291, 1997. © 1997 Wiley-Liss, Inc.     

Fine-needle aspiration biopsy of vertebral body lesions: Cytologic,pathologic, and clinical correlations of 57 cases

We reviewed 57 cases of fine-needle aspiration biopsy (FNAB) specimens of vertebral body lesions at our institutions and sought correlations between clinical histories, aspirates, and tissue specimens. Patients'ages ranged from 10–86 yr (mean 62 yr). Previous clinical histories included malignancy (n = 33), osteomyelitis or systemic infection (n = 18), and nonspecific (n = 6). FNAB diagnoses were rendered in 81% of cases (n = 46) and were correlated with previous clinical history (P < 0.004). Tissue diagnoses were also correlated with previous clinical history (P < 0.02). In 19% of cases (n = 11), FNAB was unsatisfactory; of these, tissue specimens were diagnostic for five cases. In 19% of cases (n = 11), both aspirates and tissue specimens were available, and the diagnoses coincided in all cases; tissue specimens did not enhance the results of aspirates which produced positive results. Aspirates which showed normal bone marrow elements appeared to effectively rule-out metastatic malignancy based on clinical follow-up (mean 3.7 yr). Diagn Cytopathol 1994;11:348–351. © 1994 Wiley-Liss, Inc.     

Fine-needle aspiration of secondary neoplasms involving the salivary glands. A report of 36 cases

Metastases or secondary deposits account for 16% of the malignant neoplasms involving the major salivary glands. A correct diagnosis of a secondary neoplasm is important to avoid unnecessary radical surgery and to guide further therapy. Fine-needle aspiration biopsy (FNAB) is an excellent noninvasive diagnostic tool for evaluating salivary gland lesions. We reviewed 36 secondary malignant salivary gland neoplasms evaluated by FNAB. Ancillary studies were performed in selected cases. Follow-up included clinical correlation and review of histologic material. For 4 adenocarcinomas, 4 squamous cell carcinomas, 1 undifferentiated carcinoma, 1 cutaneous basal cell carcinoma, 10 cutaneous melanomas including 1 desmoplastic variant, 3 osteosarcomas, 11 non-Hodgkin lymphomas, and 2 multiple myelomas, there was 1 false-negative FNAB result. The desmoplastic melanoma was interpreted as reactive lymphoid hyperplasia. A malignant diagnosis was given in all remaining cases except the secondary basal cell carcinoma, which was diagnosed as a neoplasm with basal cell features. FNAB is a reliable tool to differentiate hematologic malignant neoplasms and melanomas from other salivary gland neoplasms. A complete knowledge of the clinical history, review of previous pathologic materials, and, in some instances, the use of ancillary studies are crucial for recognizing solid malignant neoplasms secondarily involving the salivary glands.     

A unique case of bilateral ovarian splenosis and review of the literature

Splenosis is an acquired anomaly related to heterotopic auto‐transplantation of splenic tissue following abdominal trauma or splenectomy. We report the first definitive bilateral ovarian case in a 65‐year‐old woman who underwent splenectomy following a motor vehicle accident 44 years prior to presentation. We review the literature and discuss the main differential diagnoses. Gross examination revealed a 1‐cm well‐circumscribed dark nodule on the surface of each ovary. Paraffin‐embedded, formalin‐fixed blocks were sectioned and stained with hematoxylin–eosin and immunostains (CK5/6, Calretinin, WT1, Vimentin). The histological presence of both red and white splenic pulp, delimitation from ovarian tissue and ovarian origin of blood supply, as well as medical history, led us to the correct diagnosis. The outer nodular surface was covered by mesothelium (WT1+, CK5/6+, Calretinin+, Vimentin+), which was in continuity with the ovarian surface epithelium. To our knowledge, only six previous cases of ovarian splenosis are reported. Our patient is the oldest, with a very long interval from splenectomy to presentation. Clinically, splenosis may mimic malignancy, and a correct diagnosis avoids unnecessary overtreatment. The differential diagnosis includes an accessory spleen, spleno‐gonadal fusion, and splenic hamartoma: they should be excluded to come to the correct diagnosis.     

Role of repeat fine-needle aspiration biopsy (FNAB) in the management of thyroid nodules

The purpose of the present study was to determine the role of repeat fine-needle aspiration biopsy (FNAB) in the evaluation of thyroid nodules initially classified as "nondiagnostic" due to limited cellularity or as "indeterminate for neoplasm." We reviewed a cohort of 431 patients (352 females, 79 males; average age 50 yr); 237 patients were classified as "nondiagnostic" due to limited cellularity and 194 as "indeterminate for neoplasm" over a 3-yr period (1999-2002). Repeat FNAB under ultrasound guidance was performed in 226 patients (226/431, 52%); surgical pathology results were available in 101 patients. Repeat FNAB diagnoses were: benign 70 (31%), follicular/Hürthle cell neoplasm 62 (27%), suspicious for papillary carcinoma 25 (12%), malignant 17 (7%), and nondiagnostic 52 (23%) cases. Surgical follow-up was available in 101 (45%) patients; malignancy was identified in 50 (49%) patients. The malignancy rate was 51% and 48% in cases in which initial FNAB was nondiagnostic and indeterminate for neoplasm, respectively. There were no false-positives and all malignant cases undergoing surgery were found to be malignant. This study demonstrates that repeat FNAB is warranted in patients with thyroid nodules diagnosed on initial FNAB as nondiagnostic and indeterminate for neoplasm since it can yield a definitive diagnosis in the majority of cases with an overall malignancy rate of 49%.     

Metachronous soft-tissue masses in children and young adults with cancer: correlation of histology and aspiration cytology

We describe a series of 28 fine needle aspiration biopsies (FNAB) of soft tissue from 22 patients. Four patients had two separate FNABs, and one had three aspiration procedures. The patient population was limited to children and young adults (age range, 2 months to 29 years; mean, 16 years) who were known to have diverse forms of cancer, and who subsequently developed a mass in the peripheral soft tissues (including breast). The interval between the time of diagnosis of the primary malignant neoplasm and FNAB ranged from 1 day to 17 years (mean, 39 months). All FNAB diagnoses were confirmed by subsequent surgical open biopsy or clinical follow-up greater than 1 year. No complications occurred from the procedure. The cytomorphology is presented in selected cases and correlated with the patient's original tissue histopathology. Twenty aspirates were diagnosed as cytologically malignant, one as suspicious for malignancy. Seven were considered benign. None were unsatisfactory. One false-positive and no false-negative cytologic diagnoses were obtained. The overall accuracy of FNAB diagnoses was 96%, while sensitivity was 100% and specificity 88%. Sites of aspiration included soft tissues of the head and neck (seven cases), trunk (eight cases), breast (four cases), and extremities (nine cases). Malignant cytologic diagnoses included sarcoma (thirteen), seminoma (two), lymphoma/leukemia (two), melanoma (one), undifferentiated neoplasm (one), and neuroblastoma (one). Electron microscopy of aspirated cells was used to confirm the diagnosis in two cases. Fine needle aspiration biopsy of soft tissue masses from children and young adults with cancer demonstrates a high diagnostic accuracy, and its use is justified in this population.     

Mass-forming extramedullary hematopoiesis diagnosed by fine-needle aspiration cytology

Extramedullary hematopoiesis (EMH) is usually a microscopic finding. However, it may present as a mass-forming lesion making it amenable to fine-needle aspiration biopsy (FNAB). When mass-forming EMH occurs, it can simulate a neoplasm clinically and radiologically. Additionally, the megakaryocytes can mimic malignant neoplastic cells, particularly if EMH is not a considered diagnosis. We report six cases of mass-forming EMH diagnosed by FNAB and evaluate the utility of FNAB in diagnosing EMH. Four patients had prior diagnoses of hematologic disorders, one patient had malignant mastocytosis who presented with lymphadenopathy and one patient had a history of carcinoma. The patients' ages ranged from 46 to 78 yr with an equal sex distribution. Aspirate smears showed trilineage hematopoiesis. The cytomorphologic differential diagnosis included metastatic carcinoma, Hodgkin lymphoma and myeloid sarcoma. No special stains were necessary due to the classic cytologic findings and prior hematologic history.     

Fine-needle aspiration biopsy of vertebral and intervertebral disc lesions: specimen adequacy, diagnostic utility, and pitfalls.

BACKGROUND AND OBJECTIVES: Fine-needle aspiration biopsy (FNAB) is used extensively in the clinical workup of radiologically detected bony lesions. The aims of this study were to evaluate the diagnostic utility of FNAB of such radiologically detected vertebral and intervertebral disc lesions in patients with and without a known primary malignancy, to establish criteria for specimen adequacy, and to evaluate the diagnostic pitfalls. DESIGN: The cytologic material obtained by FNAB performed under computed tomographic guidance of 78 cases comprising 66 vertebral and 12 intervertebral disc lesions was reviewed and analyzed. The initial cytologic diagnosis was compared with the diagnosis after review in all 78 cases. RESULTS: Thirty-five cases (45%) were positive for malignancy, 1 case (1.3%) was suspicious for malignancy, 9 (11.5%) consisted of normal cellular elements with no evidence of malignancy, 21 (27%) were unsatisfactory/inadequate for diagnosis, and 12 (15.2%) were benign nonneoplastic lesions. Nonneoplastic lesions diagnosed included fracture callus, discitis/osteomyelitis, degenerative disc disease, and Paget disease. In 11 cases, FNAB gave the initial diagnosis of malignancy (8 occult carcinomas and 3 plasmacytomas). In 23 out of 36 cases with a clinical history of a known primary tumor, FNAB established the diagnosis of metastases, and in 1 case, a second primary was detected. CONCLUSIONS: Fine-needle aspiration biopsy of radiologically suspected vertebral and intervertebral disc lesions in patients with a history of a known malignancy is useful to confirm the presence of metastases. In cases without any history of malignancy, FNAB can provide additional clues to aid in the subsequent workup and treatment of cases diagnosed with an unsuspected malignancy and other nonneoplastic lesions. Through assessment of the specimen adequacy, correct interpretation of the cytologic material available, and correlating with the clinical and radiologic findings, a definitive diagnosis can be made in most cases.     

Utilization of fine-needle aspiration biopsy in the diagnosis of metastatic tumors to the pancreas

There is relatively little information concerning the use of fine-needle aspiration biopsy (FNAB) to diagnose a mass in the pancreas that is secondary to metastatic tumor. This study reviews the incidence and types of neoplasms which metastasize to the pancreas and assesses the contribution FNAB can make in their diagnosis. of 117 radiologically guided FNABs of the pancreas, 11% (n = 13) showed metastatic malignancy. Nine patients had a previous history of malignancy while four patients presented with a pancreatic mass and were subsequently found to have widespread malignant disease. the majority of metastatic lesions were epithelial (77%, n = 10). Patient outcomes were generally poor (mean survival 2.8 mo). Metastases to the pancreas occur from a variety of primary sites and should be considered in patients with a pancreatic mass and a history of prior malignancy. FNAB is useful in diagnosing these metastases and this is clinically important because of their poor prognosis.     

Fine-needle aspiration cytology of thymic basaloid carcinoma: case studies and review of the literature

We report the features in fine-needle aspiration biopsy (FNAB) of thymic basaloid carcinomas. This is a rare neoplasm, of which there are only three documented in our hospital files. To the best of our knowledge, this is the first fine-needle aspiration (FNA) report on basaloid carcinoma of the thymus. This is a tumor in which the FNA diagnosis is difficult and the differential diagnosis is broad. We describe the cytologic features encountered in the three cases, and immunohistochemical and ultrastructural findings so as to raise awareness of this entity in the differential diagnosis of thymic neoplasms on FNABs. The cases studied included three male patients, aged 73, 65, and 50, who presented with anterior mediastinal masses, with no primary tumor elsewhere. FNAB was performed on two cases, followed by thymectomy. One case, additionally, had metastasis to a cervical lymph node, and the other two were associated with thymic cysts. The diagnoses on all three cases were thymic basaloid carcinoma.     

The reliability of fine-needle aspiration biopsy in the diagnosis of deep lesions of the lung and mediastinum: experience with 250 cases using a modified technique

Two-hundred and fifty discrete lesions of the lung and mediastinum were sampled by a modified fine-needle aspiration biopsy (FNAB) technique. Aspirates were collected directly into 15 ml of Saccomanno's fixative, and all preparative work was carried out in the cytopathology laboratory. Only seven aspirates were "insufficient for diagnosis," giving a productivity rate of 97%. Five insufficient aspirates later proved to be neoplasms. Of the 243 cases with a primary FNAB diagnosis, 21 had insignificant disease, 29 had benign neoplasms or nonneoplastic disease, and 193 had malignant tumors. Most malignancies could be assigned to a specific histologic type by FNAB; those that proved difficult by FNAB were usually difficult on histopathologic examination. There were no false-positive diagnoses of malignancy and only eight false-negative results. Of 12 results interpreted as "suspicious," 10 proved to be malignant on follow-up. This modified method has proven to have a low complication rate and to be both highly productive and reliable in the diagnosis of malignant and nonmalignant disease.     

KP-1: not a specific marker. Staining of 137 sarcomas, 48 lymphomas, 28 carcinomas, 7 malignant melanomas and 8 cystosarcoma phyllodes

This study documents the reactions of the monoclonal antibody KP-1, which detects histiocytes in paraffin sections, with 137 sarcomas, 48 lymphomas, 28 carcinomas, 7 malignant melanomas and 8 cystosarcoma phyllodes. The soft tissue sarcomas had been previously immunophenotyped. Positive staining was obtained in all categories of sarcoma except clear-cell sarcomas. Most categories of sarcoma showed staining in less than 10% of tumour cells although a minority of leiomyosarcomas showed more extensive staining. Five of 7 malignant melanomas were also positive while all lymphomas and carcinomas were negative. We conclude that KP-1 positivity is not helpful in supporting the histiocytic origin of a tumour and is of limited value in the differential diagnosis of soft tissue sarcomas or their separation from other categories of malignancy.     

Thoracic splenosis diagnosed by fine-needle aspiration cytology: a case report.

A case of thoracic splenosis diagnosed by fine-needle aspiration (FNA) of subpleural lung lesions is presented. The patient, a 49-yr-old male with a history of gunshot wound to his trunk with splenic rupture and splenectomy several years previously, presented with recent hemoptysis and multiple subpleural solid nodules shown in the left lung field by CT scan. As the possibility of a metastatic malignancy vs. mesothelioma was entertained, an FNA was performed on one of these lesions, revealing lymphoid tissue with abundant vascularity simulating the structure of splenic tissue. In view of this finding, supported by the absence of splenic outline in the CT radiograph, the diagnosis of splenosis was made. This is the fourth reported case of thoracic splenosis in which FNA cytology was utilized for diagnosis, yet the first in which the diagnosis was based exclusively on the FNA cytologic findings. Clinical, pathologic, and diagnostic aspects of this entity are discussed.     

Primary and metastatic high-grade carcinomas of the salivary glands: A cytologic-histologic correlation study of twenty cases

We reviewed the clinical and fine-needle aspiration (FNA) findings in 20 patients with poorly differentiated carcinomas presenting initially as parotid or as submandibular masses. There were 11 primary tumors and nine metastatic malignancies in 14 males and six females ranging in age from 39 to 89 yr (median = 66). The tumor types included three primary carcinomas with oncocytic features, three additional cases of high-grade parotid carcinoma, one case of primary neuroendocrine carcinoma, two examples of malignant mixed tumor, one high-grade mucoepidermoid carcinoma, and a single example of malignant lymphoepithelial lesion. Six patients with metastatic carcinoma had previous diagnoses of malignancy. In the three remaining individuals, primary carcinomas of the lung (two cases), and an unknown primary site presented initially as parotid masses. Five examples of metastatic squamous cell carcinoma, one metastatic basal cell carcinoma, and two metastatic renal cell carcinomas were identified. One parotid lymphoepithelioma was interpreted cytologically as an atypical lymphoproliferative process suggestive of Hodgkin's disease. Nineteen cases (95%) were correctly classified as carcinoma at the time of FNA. High-grade carcinomas aspirated from the parotid may be primary, but are frequently metastatic to either the gland, or to an intraparotid lymph node. Our experience indicates that some metastatic carcinomas present at this site, without a previous history of malignancy. Distinguishing primary from metastatic lesions has important therapeutic implications. © 1995 Wiley-Liss, Inc.     

Cytodiagnosis of amelanotic metastatic malignant melanoma: An immunocytochemical study

Malignant melanomas are known to present diverse patterns and this can result in considerable difficulties for an interpretation of malignancy type from cytohistologic material. Such difficulties are further compounded, if melanin pigment cannot be demonstrated by conventional histochemical stains; unfortunately many cases do exhibit this feature, especially in its metastases. This study was designed to review cases of amelanotic metastatic malignant melanomas in a variety of cytologic samples which were received from 40 patients with a known history of malignant melanoma. Cytomorphologically, the cases were classified as classical, carcinoma-like, spindle cell type, lymphoma-like, and undifferentiated type (Table I). While in 36 of the cases, the diagnosis of metastases from a melanoma was confirmed based on an immunopositivity to a variety of melanoma markers (Table III), in four of the cases, the immunostaining indicated metastases from another primary source, which was subsequently found. Based on our study, we are of the opinion that an immunologic characterization is useful to conclusively diagnose the majority of cases of metastatic amelanotic malignant melanomas. Furthermore, we feel that a reliance on a single melanoma marker is not justified, and a panel of antibodies should be used to distinguish a metastatic amelanotic malignant melanoma from other metastatic neoplasms. Diagn. Cytopathol. 16:238–241, 1997. © 1997 Wiley-Liss, Inc.     

Fine-needle aspiration biopsy of metastatic Ewing's sarcoma with MIC2 (CD99) immunocytochemistry

The use of fine-needle aspiration biopsy (FNAB) has been infrequently described as a diagnostic modality for Ewing's sarcoma (ES) patient follow-up and management. The purpose of this study is to examine the use and accuracy of FNAB combined with MIC2 immunocytochemistry for evaluating metastases in patients with ES. Records from Saint Louis University Health Sciences Center and Indiana University Medical Centers identified patients with known ES who had undergone FNAB for evaluation of potential metastases. Immunocytochemical analysis for MIC2 (CD99) was performed retrospectively on cell blocks and direct aspirate smears. FNABs from nine patients were procured either percutaneously or under radiologic guidance and in all cases a definitive cytologic diagnosis of metastatic ES was rendered. Aspirates were cellular with many single discohesive small round cells and occasional loosely cohesive clusters. The nuclei were round with a fine chromatin pattern and small nucleoli. The cytoplasm was scanty and the nuclear-cytoplasmic ratio was high. Six of six cases showed strongly positive immunocytochemical labeling for MIC2. Immunocytochemistry with MIC2 in FNAB aspirate smears can provide supportive evidence of ES in patients with known disease. Diagn. Cytopathol. 1998;19:382–384. © 1998 Wiley-Liss, Inc.     

Reliability of fine-needle aspiration biopsy in the initial diagnosis of soft-tissue lesions

We retrospectively reviewed fine-needle aspiration biopsy (FNAB) specimens of 301 soft tissue lesions of the extremities and trunk. Final diagnoses were 137 benign and 86 malignant neoplasms and 78 nonneoplastic lesions. Of the 301 FNAB samples, 279 (93%) were adequate for cytologic diagnosis. The adequate FNAB specimens were initially grouped into three broad categories: benign (197 cases), malignant (57 cases), and suspicious for malignancy (25 cases). Sensitivity and specificity for diagnosis of a malignant lesion were 92% and 97%, respectively. The specimens were cytomorphologically classified into nine categories: small round (14 cases), spindle cell (77 cases), epithelioid/polygonal (16 cases), pleomorphic (29 cases), myxoid (19 cases), lipomatous (37 cases), epithelial (23 cases), inflammatory lesions (28 cases), and others (36 cases). Specific FNAB diagnoses were correct in 151 of 279 cases (54%) in combination with clinical and radiologic findings. FNAB is a valuable technique for the primary diagnosis of soft-tissue lesions.     

A Bethesda‐like system for breast cytopathology: A retrospective assessment two decades on

Fine‐needle aspiration biopsy (FNAB) has been used for many decades in the investigation of breast lesions. Originally, cases were signed out using the categories benign and malignant. The benign category contained specimens showing fibrocystic change as well as benign neoplasms such as fibroadenoma. The malignant category contained carcinomas, lymphomas, and phyllodes tumors with specific diagnoses often given in place of the term malignant. Categorization was less clear when the cytopathologists could not definitively separate benign from malignant. This led to the use of terms, such as atypical, suspicious for malignancy, and atypical suspicious with variable definitions and utilization among cytopathologists. In 1997, a uniform approach to breast FNAB was proposed with well‐defined diagnostic categories and criteria. This system foreshadowed the recent International Academy of Cytology Standardized Reporting System for Breast Fine‐Needle Aspiration Biopsy. These two systems are compared and contrasted.     

Fine-needle aspiration cytology of splenic hamartoma

Bench-top fine-needle aspiration biopsy (FNAB) following splenectomy and nephrectomy from a 21-yr-old female of tuberous sclerosis with right renal angiomyolipoma and splenic hamartoma was performed for the correlation of the cytologic features with histologic findings and, along with the immunopathologic studies, for the establishment of a challenging preoperative diagnosis of splenic hamartoma. The postoperative bench-top aspirate of splenic hamartoma yielded small and large clusters of plump, spindly to polygonal cells in the blood-stained background with scattered small lymphocytes, comparable with the preoperative echo-guided FNAB. The histopathology and immunopatholgy of the splenic hamartoma from the bench-top aspirate cytoblock and splenectomy tissue were comparable, unveiling the red pulp tissue consisting of wider cord stromal tissue than its normal counterpart with sinus-like vascular channels lined by endothelial cells which were positive for CD8, CD34, factor VIII-related antigen, vimentin, as well as negative for muscle-specific actin, CD21, CD68, and cytokeratin, scattered dispersed CD3- and CD45RO-positive T-lymphocytes, and small clusters of CD20-positive B lymphocytes, with a dearth of fibrous trabeculae and organized white-pulp lymphoid tissue. A combination of cytologic features and immunopathologic results from the aspirate cytoblock along with the salient clinical information should enable an accurate preoperative diagnosis of splenic hamartoma.