Fine-needle aspiration of leiomyosarcoma: a correlative cytohistopathological study of 96 tumors in 68 patients

Incidental deep soft tissue leiomyoma of the groin - a case report and comprehensive review of literature

Leiomyomas are rare, benign tumors arising from smooth muscle cells. Due to the heterogeneous anatomical locations, as well as clinical and radiological findings, early and correct diagnosis is usually tricky. The clinical symptoms depend on the anatomical structure the tumors are compromising by their growth. We present a case of a 53-year-old male patient who suffered from swelling of the right foot and ankle. Initially, arthritis and deep vein thrombosis were ruled out. As the swelling progressed to the entire leg, CT scan was performed showing a tumor compressing the right femoral vein. However, a magnetic resonance imaging (MRI) and a biopsy did not show any conclusive findings. Tumor excision was planned and immunohistochemical staining confirmed leiomyoma. The authors conclude that unspecific, progressive symptoms should prompt further investigation and whenever planning a biopsy, a possible malignant finding should be considered and excision of the biopsy canal together with the tumor must be assured.

Cytologic features of metastatic epithelioid uterine leiomyosarcoma to the pancreas

Although uterine leiomyosarcoma (ULMS) is a rare disease, it accounts for a significant proportion uterine cancer-related deaths due to frequent metastasis and chemoresistance. The WHO currently recognizes the conventional (spindle), myxoid, and epithelioid variants of ULMS, the latter of which is the rarest, least understood, and cited as clinically more aggressive than the other variants. Descriptions of the histologic features of epithelioid ULMS are extremely limited, and are absent from the cytology literature which has only published descriptions of conventional ULMS or epithelioid variants of other LMS primaries. Therefore, we present a unique case of metastatic epithelioid ULMS to an unusual location, the pancreas, along with its cytologic features on endoscopic ultrasound-guided fine needle aspiration not previously described including pseudoglandular arrangements, scant cytoplasm, and frequent molding.

Cytopathology of rare gastric mesenchymal neoplasms: A series of 25 cases and review of literature

BACKGROUND

Gastrointestinal stromal tumour (GIST) is the most common mesenchymal neoplasm arising in the stomach. However, a number of other rare mesenchymal neoplasms do occur at this anatomic site, which often presents a diagnostic challenge for cytopathologists on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Our study aims to selectively present the clinico-radiological and cytopathological characteristics of these rare "non-GIST" neoplasms, as well as their differential diagnoses.

MATERIAL AND METHODS

We performed a 20 year retrospective search in the cytopathology database of our two large medical institutions for non-GIST mesenchymal neoplasms arising in the stomach and diagnosed on EUS-FNA. Data regarding the patients' demographics and radiological findings were analysed. All available cytopathology specimens were reviewed. The cytomorphological characteristics and the accompanying immunohistochemical stains, when available, were subsequently analysed.

RESULTS

Twenty-five cases of gastric mesenchymal tumours were selectively included in the study after excluding all cases of GIST (n = 113) diagnosed on FNA. These cases included 10 leiomyomas (40%), eight schwannomas (32%), five glomus tumours (20%), one perivascular epithelioid cell neoplasm, and one desmoid tumour. The specimen cellularity was variable and ranged from hypocellular to highly cellular. Most smears were composed of spindle cells with a few showing epithelioid morphology. Cell blocks were available in 20 cases and a range of immunohistochemical ancillary studies were performed. DOG-1, c-KIT, smooth muscle actin (SMA), and S100-protein were the most common immunomarkers done.

CONCLUSION

Our study highlights important cytomorphological characteristics of rare mesenchymal neoplasms arising in the stomach. In the appropriate clinical setting and with the help of immunohistochemistry, an accurate diagnosis of these neoplasms can be achieved.

Periosteal Myxoid Leiomyosarcoma Histologically Mimicking Extraskeletal Myxoid Chondrosarcoma: Report of a Case with Histopathological and Cytopathological Comparison with Extraskeletal Myxoid Chondrosarcoma

Myxoid leiomyosarcoma (MLS) is a rare variant of leiomyosarcoma, with most cases occurring in the uterus. A case of MLS arising in the periosteal region of the tibia, mimicking extraskeletal myxoid chondrosarcoma (EMC), is described. The evaluation included histological and cytological comparison with EMC. The patient was a 77-year-old man with a palpable mass at the anterior aspect of the right lower leg. After diagnosis by cytopathology and biopsy examination, a wide resection was performed. The resulting cytological smears were composed primarily of spindle-shaped tumor cells in a myxoid and hemorrhagic background. Histologically, the tumor showed abundant myxoid matrix and tumor cells proliferating in a cord-like to reticular pattern, exhibiting a lace-like arrangement that mimicked EMC. Although immunohistochemical findings suggested leiomyosarcoma, a diagnosis of EMC eventually was excluded by the lack of a split signal when assessed for a rearrangement of NR4A3 by chromogenic in situ hybridization. Despite histological similarity to EMC, characteristic cytological findings of EMC such as epithelioid structures with a cord-like pattern and chondroblast-like lacunar structures were not observed in the smears of this patient's MLS. We propose that cytopathological examination of bone and soft tissue lesions is useful as a diagnostic tool in similar cases. A total diagnostic workup, including clinical, radiographic, cytopathological, histopathological, and molecular findings, is needed to ensure an accurate final diagnosis and to reduce diagnostic error.

Mesenchymal neoplasms of the tubular gut and adjacent structures: experience with EUS-guided fine-needle aspiration cytopathology

INTRODUCTION

Unlike epithelial malignancies, mesenchymal neoplasms arising within the tubular gut are less often encountered in endoscopic ultrasound-guided (EUS) fine-needle aspiration biopsies (FNABs). Nonetheless, preoperative diagnosis of such neoplasms has important therapeutic and prognostic value. We report our experience with this category of neoplasms from the past decade.

MATERIALS AND METHODS

We performed a 10-year retrospective search at our respective institutions to identify EUS-guided FNAB cases of mesenchymal neoplasms arising from the tubular gut wall and closely adjacent structures. Cytopathologic diagnoses were compared to corresponding surgical pathology (SP) when available. Cases with either no confirmatory cell block (CB) immunohistochemical (IHC) staining, or no SP were excluded.

RESULTS

Two-hundred eighty-two cases (M:F = 1:1; age range: 25-94 years, mean age = 60 years) of EUS-guided FNAB from the tubular gut met our criteria. Onsite adequacy was performed on nearly all cases. Case numbers: 209 gastrointestinal stromal tumors (GIST), 58 smooth muscle neoplasms, and 15 miscellaneous neoplasms. Of these, 188 (67%) had SP follow-up. We found that 258 (91%) aspirates had a correct specific diagnosis, 3 (1%) were nondiagnostic, 18 (6%) had indeterminate diagnoses, and 3 (1%) had incorrect diagnoses (2 leiomyosarcomas mistaken as leiomyoma, and 1 fibrosclerotic lesion mistaken as inflammatory pseudotumor). Of 94 cases with no SP, all had a specific cytologic diagnosis based on confirmatory IHC staining from the CB including 61 GISTs, 29 smooth muscle neoplasms, and 4 miscellaneous tumors.

CONCLUSION

This study endorses the clinical utility of EUS-guided FNAB in the diagnosis of tubular gut mesenchymal neoplasms. A definitive and accurate diagnosis is possible in over 90% of cases, chiefly when cytomorphology is coupled with optimal cellularity and IHC from a concurrent CB. EUS-guided FNAB diagnosis of mesenchymal tubular gut neoplasms may play an important role in determining neoadjuvant therapy as targeted therapy evolves.

Soft tissue tumor diagnosis: A three prong approach utilizing pattern analysis, immunocytochemistry, and molecular diagnostics

Tissue diagnosis of a soft tissue neoplasm is of paramount importance for the development of an appropriate treatment plan. Biopsy technique including approach and biopsy method is important to the success of diagnosis and subsequent treatment. Histologic and cytologic diagnoses are difficult and complicated by the large number of soft tissue lesions described, distinctly different biopotential for morphologically similar lesions, often small biopsy specimen size, and the generally limited experience many pathologists have in the diagnosis of soft tissue neoplasms. While utilized less frequently than core-needle biopsies, fine-needle aspiration is a valuable initial approach for the classification of soft tissue neoplasms. The combination of pattern based morphologic analysis, immunohistochemistry, and molecular diagnostics represents a utilitarian and generally successful approach for the diagnosis of soft tissue lesions.

Plexiform Fibrohistiocytic Tumor Presenting as a Central Neck Mass Clinically Mimicking a Thyroglossal Duct Cyst: An Unusual Case Reported with Histo-cytopathologic Correlation and a Review of the Cytopathology Literature

We present the case of an uncommon example of a plexiform fibrohistiocytic tumor (PFHT) occurring in the anterior central neck region of a 40 year-old female with previous subtotal thyroidectomy. The tumor clinically mimics a complicated thyroglossal duct cyst. On fine needle aspiration cytology, the tumor was composed of sheets of bland spindle cells and nests of plump histiocytoid cells in vaguely whorled arrangements. Occasional multinucleated giant cells were also identified. The excised specimen showed an irregular, highly infiltrative subcutaneous tumor arranged in a nodular/plexiform pattern concentrated to the center of the tumor mass. In addition, the tumor contained numerous tongue-like extensions composed of variably cellular, fibroblastic/fibromatosis-like areas. These fibroblastic/fibromatosis-like extensions reached far from the epicenter of the tumor and were associated with scattered small plexiform nodules of histiocytic cells. These tongue-like extensions multifocally involved the surgical margins. The fibroblastic and histiocytoid cells showed diffuse smooth muscle actin (SMA) expression. The multinucleated giant cells and also the histiocytoid proliferation were positive for CD68. This case illustrates an uncommon both anatomical and demographic manifestation of PFHT and also characterize the fine needle aspiration cytologic features in this tumor, which previously have been reported in a few cases.

Uterine pleomorphic leiomyosarcoma with osteoclastic giant cells: Case report with peritoneal washing cytology and cell block study

Uterine leiomyosarcoma (LMS) with osteoclastic giant cells (OGCs) is extremely rare. However, its morphological appearance and aggressive behavior may have resulted in its being diagnosed as so-called giant cell malignant fibrous histiocytoma (MFH) in the past. Effusions are not uncommon in LMS and may be indicative of an unfavorable prognosis. We report a case with the cytological appearance of a uterine LMS with OGCs metastatic to lower pelvic peritoneum. The pelvic washing specimen consisted of three-dimensional aggregates of atypical cells. The cytohistologic and immunohistochemical study obtained from the cell block and the tumor mass showed overlapping features such as bizarre pleomorphic spindle cells containing numerous evenly dispersed OGCs. The malignant tumor cells showed extensive positivity for desmin, h-caldesmon and multifocal positivity for smooth muscle actin (SMA) whereas OGCs stained with CD68. We stress the usefulness of performing cell block and subsequent immunohistochemistry in order to make an accurate cytohistologic correlation.

Superficial CD34-positive fibroblastic tumor: Cytologic features, tissue correlation, ancillary studies, and differential diagnosis of a recently described soft tissue neoplasm

Superficial CD34-positive fibroblastic tumor is a low-grade mesenchymal neoplasm of superficial soft tissues characterized by fascicles of spindle to epithelioid cells displaying nuclear pleomorphism and strong diffuse CD34 immunoreactivity. The intraoperative imprint cytology preparations (ICP) of a superficial CD34-positive fibroblastic tumor from a 50-year-old female are described. To the best of our knowledge, there is no report of the cytologic findings of superficial CD34-positive fibroblastic tumor in the English medical literature. The ICP, differential diagnosis, tissue correlation, and ancillary studies of this fascinating entity are discussed. Diagn. Cytopathol. 2016;44:926-930. © 2016 Wiley Periodicals, Inc.

Effectiveness of histology and cytology on musculoskeletal tumor diagnosis

OBJECTIVE:

To compare cytology and histology on the diagnosis of musculoskeletal neoplasms.

METHOD:

Fifty eight cases available to evaluation were analyzed both by cytology and histology. The results of the biopsies studied by histology and cytology were compared to the results obtained on the surgical specimen or immunohistochemistry. We determined the percentage of correct results, sensitivity, specificity, positive and negative predictive values and accuracy of each method.

RESULTS:

Twelve per cent of biopsies were inconclusive by cytology. The percentage of correct diagnosis was 70.7% and 81% (p=.179), the ability to differentiate benign lesions from malignant ones was 84.5% and 93.1% (p=0.18) respectively, for cytology and histology. Cytology showed sensitivity of 87.8%, specificity of 76.5%, positive predictive value of 90%, negative predictive value of 72% and accuracy 84.5%. Histology showed sensitivity of 90.2%, specificity of 100%, positive predictive value of 100%, negative predictive value of 81% and accuracy of 93.1%. The Youden index for cytology was 64.3% and for histology it was 90.2%.

CONCLUSION:

Despite promising, cytology obtained by thin needle aspiration is less accurate and reliable than the histological evaluation on musculoskeletal tumors diagnosis.

Level of Evidence II, Diagnostic Studies.

Ultrasound-guided fine needle aspiration cytology of a primary lymph node leiomyoma: a flexible procedure for a complex case

BACKGROUND

A primary lymph node leiomyoma diagnosed by fine needle aspiration cytology (FNAC) is reported.

CASE

A 22-year-old male complained of right groin swelling; ultrasound examination (US) showed a lymph node containing a 20-mm hypoechoic nodule. The residual lymph node was oval, with a well-characterized cortex and hilum. US-FNAC of the nodule showed oval spindle cells embedded in fibrillar matrix. Nuclei were naked and oval with dispersed chromatin but without nucleoli. Immunocytochemistry showed positivity for vimentin and actin, and negativity for cytokeratin, S100, CD23 and CD31. A smear of the residual lymph node showed a reactive lymphoid cell population. FNAC diagnosis was mesenchymal cell proliferation with smooth muscle phenotype; a lymph node is part of the lesion. A CT scan did not detect any inguinal or abdominal mass. The surgical sample was a lymph node containing a spindle cell tumor, which was actin and desmin positive, and S100, CD21, HMB45, CD23 and CD31 negative; MIB1 was positive in <5% of the cells. The residual lymph node was normal.

CONCLUSION

The final diagnosis was primary benign leiomyoma in a lymph node. US-FNAC may frame complex lymph node lesions and provide treatment options.

The role of cytology in the diagnosis of musculoskeletal neoplasms: systematic review

The authors systematically reviewed the literature of the last decade on the role of cytology in the evaluation of musculoskeletal neoplasms, and its diagnostic accuracy. A search was carried out on the databases PubMed, MEDLINE, LILACS and SciELO, selecting articles in which cytology was used in the diagnosis of musculoskeletal neoplasms. Limits were used for English, Spanish and Portuguese, and only articles published since 2000 were selected. 757 articles were retrieved, 24 of which were selected based on criteria of inclusion and exclusion. It was concluded that although promising in the assessment of musculoskeletal neoplasms, cytology obtained by fine needle aspiration is less accurate and reliable than histological evaluation of such lesions.

[Cytologic diagnosis of sarcoma]

Soft tissue swelling represents a common clinical sign of a variety of neoplastic and non-neoplastic lesions. Sarcoma is rarely a cause. Fine needle biopsy as a minimally invasive, economic and accurate method is well suited for the diagnosis of inflammatory/infectious processes as well as of recurrent and metastatic disease. Cytologic diagnosis of primary soft tissue tumors is also feasible. It requires close collaboration with other medical disciplines and incorporation of clinical, radiological and morphologic findings. Clinical data such as age, gender, size and topography are important parameters. The differentiation of cells and properties of the extracellular matrix supplies clues for the differential diagnosis and forms the starting point for immunohistochemical or molecular analysis (FISH, RT-PCR). This analysis may be performed on cytological smears, paraffin embedded material of the cell blocks or on frozen material.

Fine-needle aspiration cytology features of a recurring plexiform fibrohistiocytic tumor in the upper limb and review of the literature

Plexiform fibrohistiocytic tumor is a rare soft tissue tumor that has a propensity to occur in the extremities in adolescents and young adults. Its cytologic features are not well documented, with only two case reports available in the literature. We present the case of a recurrent plexiform fibrohistiocytic tumor in a 19-year-old male, the cytologic features of which mimic that of a high-grade sarcoma. We discuss the likely differential diagnosis based on the cytologic findings and a review of the current literature on this highly unusual tumor is also performed.

A comparison of fine-needle aspiration, core biopsy, and surgical biopsy in the diagnosis of extremity soft tissue masses

BACKGROUND

Biopsy tissue can be obtained through a fine needle, a wider coring needle, or through an open surgical incision. Though much literature exists regarding the diagnostic yield of these techniques individually, none compare accuracy of diagnosis in the same mass.

QUESTIONS/PURPOSES

We asked how the diagnostic accuracy of fine-needle aspiration, core biopsy, and open surgical biopsy compare in regard to identifying malignancy, establishing the exact diagnosis, and guiding the appropriate treatment of soft tissue masses.

PATIENTS AND METHODS

We prospectively studied 57 patients with palpable extremity soft tissue masses, performing fine-needle aspiration, followed by core biopsy, followed by surgical biopsy of the same mass.

RESULTS

Open surgical biopsy was 100% accurate on all accounts. With regard to determining malignancy, fine-needle aspiration and core biopsy had 79.17% and 79.2% sensitivity, 72.7% and 81.8% specificity, 67.9% and 76% positive predictive value, 82.8% and 84.4% negative predictive value, and an overall accuracy of 75.4% and 80.7%, respectively. In regard to determining exact diagnosis, fine-needle aspiration had a 33.3% accuracy and core biopsy had a 45.6% accuracy. With regard to eventual treatment, fine-needle aspiration was 38.6% accurate and core biopsy was 49.1% accurate.

CONCLUSIONS

In soft tissue mass diagnosis, core biopsy is more accurate than fine-needle aspiration on all accounts, and open biopsy is more accurate than both in determining malignancy, establishing the exact diagnosis, and the guiding appropriate treatment.

Cyto-histological correlations in primary, recurrent and metastatic rhabdomyosarcoma: the institut Curie's experience

To determine diagnostic cytomorphologic features of rhabdomyosarcoma (RMS) on fine-needle aspiration (FNA) material, the cytologic material and corresponding histologic slides of 180 tumors obtained from 109 patients were reviewed. Fifty eight (32.2%) tumors were primary, 34 (18.9%) recurrent, and 88 (48.9%) metastatic. A review of original cytology reports revealed that 176 of 180 (97.8%) tumors were either diagnosed accurately or as round cell sarcoma, while 3 (1.7%) were reported as suspicious. In one case (0.5%), the material was unsatisfactory. No false negative samples were seen. When FNA morphology was correlated with different histological subtypes, the alveolar subtype RMSs were more cellular than the nonalveolar ones (91.4% vs. 64.9%). Similarly, alveolar subtype RMSs compared with nonalveolar ones exhibited more rhabdomyoblastic cells (77.1% vs. 52.7%), alveolar structures (67.6% vs. 10.8%), giant, multinucleated cells (22.9% vs. 6.7%), mitotic figures (57.1% vs. 18.9%), and cyto-nuclear atypia (77.1% vs. 43.2%). Inversely, spindle-shaped cells were more frequently seen in nonalveolar versus alveolar RMSs (37.8% vs. 20.9%).

[Cytologic diagnosis of soft tissue tumors]

Soft tissue swellings represent common clinical signs of a variety of neoplastic and non-neoplastic lesions. Sarcomas are rarely the cause. Fine needle biopsy as a minimally invasive, economic and accurate method is well suited for the diagnostics of recurrent and metastatic diseases. Cytologic diagnosis of primary soft tissue tumors is also feasible but requires close collaboration with other medical disciplines and incorporation of clinical, radiological and morphologic findings. Clinical data such as age, gender, size and topography are also important parameters. Differentiation of the cells and the properties of the extracellular matrix offer initial indications for the differential diagnosis and are the starting point for immunohistochemical and molecular analyses (FISH, RT-PCR). These analyses can be performed on cytological smears, on paraffin-embedded cell blocks on snap frozen material.

Esophageal leiomyosarcoma diagnosed by endoscopic ultrasound-guided fine-needle aspiration

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has proven itself to be a reliable method for the diagnosis of gastrointestinal stromal tumors and other gastrointestinal mesenchymal neoplasms. The diagnosis and distinction of these entities remain important, as these neoplasms have different prognoses and treatment options. We present a case of a 14.5-cm esophageal mass in a 67-yr-old woman sampled by EUS-FNA. Smears showed a cellular, spindle cell lesion with marked cytologic and nuclear pleomorphism. A cell block showed neoplastic cells reacting strongly with antibodies to smooth muscle antigens and not with antibodies to keratin, CD34 and CD117. Resection confirmed the diagnosis of esophageal leiomyosarcoma. To the best of our knowledge, this represents the first reported case of an esophageal leiomyosarcoma diagnosed by EUS-FNA. Clinical, imaging, and cytologic features as well as differential diagnosis are discussed.

Fine-needle aspiration of neurilemoma (schwannoma). A clinicocytopathologic study of 116 patients

The preoperative fine-needle aspiration cytology (FNAC) diagnoses in 116 surgically excised neurilemomas were reviewed and compared with the corresponding histopathologic diagnoses made on surgical specimens and with clinical data. In addition, the utility of adjunctive techniques was analyzed and other spindle-cell lesions in the differential diagnoses were discussed. An unequivocal, benign diagnosis was rendered by FNAC in 80 cases, 67 of which were correctly labelled as neurilemoma in a review of the original cytology reports. There were 6 false-positive malignant diagnoses while 23 smears were considered insufficient and 7 inconclusive as to whether benign or malignant. On reevaluation, the diagnostic smears in most cases contained spindle cells with wavy nuclei embedded in a fibrillar, occasionally collagenous, and/or myxoid matrix and Antoni A/Antoni B tissue fragments. A moderate to abundant admixture of round to oval cells was also frequent. Nuclear palisading was seen in 41 smears with distinctive Verocay bodies in 10. Markedly pleomorphic nuclei were seen in smears from 8 ancient and 6 conventional neurilemomas, and slight to moderate nuclear pleomorphism was observed in 38 additional cases. Thus most neurilemomas have distinct cytomorphologic features that allow correct diagnosis. The major problem in FNAC of neurilemoma is to obtain sufficient material. Furthermore aspirates showing predominantly Antoni A features, nuclear pleomorphism, and/or myxoid changes can easily be confused with other types of benign or malignant soft-tissue tumors.

Fine-needle aspiration of soft tissue leiomyosarcoma: An analysis of the most common cytologic findings and the value of ancillary techniques

This study aims to determine the diagnostic accuracy of fine-needle aspiration cytology (FNAC) of primary leiomyosarcoma (LMS) of soft tissue and to review diagnostic criteria and adjunctive methods, which can contribute to a confident diagnosis. We evaluated the preoperative FNAC in 89 patients with primary LMS for the following: cytomorphology and correspondence of FNA to histological features of excised tumors and clinical data. In addition, the utility of adjunctive techniques was analyzed and other spindle-cell lesions in the differential diagnoses were discussed. An unequivocal, malignant diagnosis was rendered by FNAC in 78 cases; 74 tumors were diagnosed as sarcoma, of which 31 as LMS or suspicion of LMS. In addition, three smears were labeled as malignant tumor, one as carcinoma metastasis, and three as neurilemmoma. Seven aspirates were inconclusive and one insufficient. On reevaluation, the diagnostic smears in most cases contained tumor cell fascicles with an admixture of dispersed cells or stripped nuclei. The most common cells were spindle cells with elongated, blunt-ended, segmented or fusiform nuclei, and round/polygonal cells, often with rounded or indented nuclei. In addition, 51 cases showed pleomorphic, often multinucleated cells. Osteoclasts, intranuclear vacuoles, and mitoses occurred in 14, 47, and 27 cases, respectively. Thus, most high-grade LMSs have cytologic features that allow diagnosis of sarcoma. Ancillary studies can confirm the diagnosis of LMS and help in the correct interpretation of predominant spindle-cell or epitheloid-cell smears resembling neurilemoma or carcinoma, respectively.

Fine-needle aspiration in liposarcoma: Cytohistologic correlative study including well-differentiated, myxoid, and pleomorphic variants

We have reviewed cytopathology and the corresponding histopathology material of 86 liposarcomas (55 patients) seen at Institut Curie. The liposarcomas (LS) were well differentiated in 14 cases (9 pure, 2 dedifferentiated, 3 sclerosing), 64 myxoid, and 8 pleomorphic. Twenty-four tumors were primary, 34 recurrent, and 28 secondary. Smears in LS were composed in different proportions of round, spindle cells, lipoblasts, and myxoid and vascular arborizing structures. Pure well-differentiated LS were frequently composed of lipoblasts, and round or spindle cells were occasionally seen. Dedifferentiated and sclerosing liposarcomas were composed of spindle or round cells, but lipoblasts were also occasionally present. Myxoid or vascular arborizing structures were absent. Myxoid LS (including round and spindle cell LS) frequently showed a myxoid background and less frequently vascular arborizing structures. Tumor cells were round or spindle. Lipoblasts were also seen. Pleomorphic LS were composed of an admixture of all cellular and stromal elements. Well-differentiated LS should be distinguished from hibernoma and spindle cell lipoma, and myxoid LS from myxoma, myxoid chondrosarcoma, chordoma, myxoid leiomyosarcoma, and myxoid malignant fibrous histiocytoma. The demonstration of the specific translocation t(12;16)(q13;p11) of myxoid LS is very helpful to establish the diagnosis. Pleomorphic LS should be differentiated from other high-grade sarcomas, whenever possible.

Cytological features of epithelioid mesenchymal neoplasms: A study of 21 cases

Epithelioid mesenchymal neoplasms (EMNs) are rare tumors that share cytological, histological, and immunohistochemical features with epithelial tumors. It is important to distinguish EMNs from epithelial tumors in cytology specimens due to their different clinical management and prognosis. The cytomorphological features of histologically confirmed EMN were reviewed. Twenty-one cytological specimens of EMN were evaluated and characterized by polygonal cells with moderate to abundant dense cytoplasm, prominent nucleoli, and pleomorphism. Additional findings included the presence of a distinct population of spindle cells, hemosiderin-containing cells, multinucleated cells, and granuloma-like structures in selected cases. Cytokeratin immunoreactivity was seen in two cases and was negative in one case. This study shows that the cytological features of EMNs and epithelial tumors overlap; nonetheless, some features are more helpful in suggesting EMN. A panel of immunocytochemical studies must include specific mesenchymal markers to avoid a misdiagnosis of carcinoma in cases of cytokeratin-positive EMN.

Comparative fine-needle aspiration and pathologic study of malignant fibrous histiocytoma: Cytodiagnostic features of 95 tumors in 71 patients

To determine diagnostic cytomorphologic features of malignant fibrous histiocytoma (MFH) on fine-needle aspiration (FNA) materials, we reviewed the cytologic material and corresponding histologic slides of 95 tumors in 71 patients. Forty-four (46%) tumors were primary, 38 (40%) were recurrent, and 13 (14%) were metastatic. Histological variants of MFH were as follows: 52 (54.7%, 43 patients) were of the storiform/pleomorphic, seven (7.4%, five patients) were giant cells, four (4.2%, four patients) were inflammatory, and 31 (33.7%, 19 patients) were myxoid type. Review of original cytology reports showed that only 23 (24.2%) tumors were diagnosed as MFH and 68 (71.6%) as other types of malignancies. Four (4.2%) cases were reported as unsatisfactory/suspicious. Our findings showed that spindle-shaped, round, giant cells, osteoclastic-like giant, and inflammatory cells were the most consistent features that allow identification of the storiform/pleomorphic, giant cell, and inflammatory variants of MFH. The myxoid tumors had marked myxoid background matrix with spindle-shaped cells and, less frequently, round and giant cells. Pleomorphic leiomyosarcoma and dedifferentiated liposarcoma should be considered in the differential diagnosis of stroriphorm/pleomorphic, giant cells, and inflammatory variants of MFH. However, myxoid MFH may resemble their leiomyosarcoma and liposarcoma counterparts.