Stereotactic biopsy diagnosis of primary non-Hodgkin's lymphoma of the central nervous system. A histological and immunohistochemical study

We report 29 cases of primary non-Hodgkin lymphomas (NHL) of the Central Nervous System (CNS), 26 of which were diagnosed by stereotactic biopsy and 3 by autopsy. In seven cases the patients were affected by AIDS. Histological examination of this series revealed 15 cases of immunoblastic lymphoma, 12 cases of centroblastic lymphoma, 1 case of lymphoplasmacytic immunocytoma and 1 case of unclassified high grade lymphoma. By immunohistochemistry the B-cell origin of lymphoma cells was demonstrated in 28/29 cases. Eight cases were assigned to the B-cell lineage by demonstration of monotypic surface or cytoplasmic immunoglobulin or of the B-cell phenotype CD22+, CD2-, CD3-, CD5-. In twenty cases the B-cell nature of lymphoma was identified by positivity with two or more anti-B monoclonal antibodies (LN1LN2MB2) and negativity by the anti-T monoclonal antibody UCHL1. The histologically unclassified case was a peripheral T-NHL (CD1-, CD2+, CD3-, CD5+, CD22-). We conclude that histological and immunohistological evaluation of stereotactic biopsy specimens provides sufficient information for diagnosis and phenotypic characterization of primary NHL of the CNS. These lymphomas exhibit important predominance of high-grade malignancy histological types and are nearly always B-cell derived. In addition, we provide further evidence that the panel of monoclonal antibodies LN1, LN2, MB2, and UCHL1 is useful for immunophenotypic characterization of brain lymphomas when only paraffin embedded stereotactic biopsy tissue is available.     

Intravascular large B-cell lymphoma. A report of five cases initially diagnosed by bone marrow biopsy.

We report 5 cases of intravascular lymphoma (IVL) initially diagnosed by bone marrow aspiration and biopsy. Each patient had generalized symptoms; 1 also had neurologic deficits. CBC counts revealed anemia (4 patients), thrombocytopenia (4 patients), or mild leukopenia (1 patient). The bone marrow biopsy specimen was diagnostic in each case. Lymphoma cells were present in small groups or single file in sinusoids (in 1 patient, sinusoids were distended markedly by IVL) and were detected in bone marrow aspirate smears (4 patients) and peripheral blood smears (all patients). Immunohistochemical studies demonstrated that every neoplasm was of B-cell lineage, CD20+, positive for other B-cell antigens, and CD3- or CD43-. Immunophenotypic studies revealed at least 2, and possibly 3, distinct immunophenotypic groups of B-cell IVL: CD20+ CD5+ (3 neoplasms), CD20+ CD5- CD10+ (1 neoplasm), and CD20+ CD5- CD10 unknown (1 neoplasm). B-cell IVL may be detected by morphologic examination of peripheral blood and bone marrow, and involvement of these sites may be more common than is reported in the literature. Immunophenotypic studies are helpful in establishing the diagnosis and suggest that B-cell IVL is a heterogeneous group of neoplasms that may arise from more than 1 normal B-cell precursor.     

Intravascular lymphomatosis of the lung and liver following eyelid lymphoma in a Chinese man and review of primary pulmonary intravascular lymphomatosis

Intravascular lymphomatosis (IVL) is characterised by an almost exclusive intravascular proliferation of malignant lymphoid cells, with the diagnosis often made only when the illness is in its terminal phase or at autopsy. We detail a case of IVL affecting the lung and liver of a 49-year-old Chinese man presenting primarily with lung symptoms and incidental findings of abnormal serum transaminase levels, the ante-mortem diagnosis being established on transbronchial lung biopsy and percutaneous liver biopsy specimens, respectively. Histology disclosed CD20 + CD5 - CD10 [corrected] - malignant large mononuclear B cells within the lumina of the blood vessels of the affected organs as well as sinusoids of the liver. Significantly, the patient had a history of large B cell lymphoma affecting the eyelid 18 months prior to the angiotropic disease, suggesting a possible link between the more common types of non-Hodgkin's lymphoma and IVL. A brief review of all cases of primary pulmonary intravascular lymphomatosis is also presented.     

子宫静脉内平滑肌瘤病临床病理与生物学行为分析

目的观察和分析子宫静脉内平滑肌瘤病（intravenous leiomyomatosis of the uterus,IVL）的临床和病理学特征,期望更好地了解其生物学行为,为临床和病理诊断提供帮助。方法回顾分析29例IVL的临床和病理资料,采用LABC法免疫组化检测desmin、SMA、CD10、vimentin、CD34、ER、PR表达。结果所有患者术前均诊断为子宫平滑肌瘤或子宫腺肌病,无1例怀疑为静脉内平滑肌瘤病。手术中,29例均行冷冻切片检查且均正确诊断为子宫静脉内平滑肌瘤病;所有病例术后经石蜡包埋病理切片检查确诊。28例全子宫切除标本中,肿块均沿脉管腔穿出宫旁或浆膜下。获访的18例患者中,1例患者在肌瘤剥出术后两次复发,行全子宫＋双侧附件切除术后随访至今无复发,其余患者随访无复发。免疫组化染色显示脉管内的肿瘤细胞desmin、SMA均阳性;脉管内皮细胞CD34阳性。结论正确认识这种少见肿瘤的大体和剖面特点可减少误诊率,术中冷冻切片检查有助于提高术中诊断率和正确选择处理方式;由于肿瘤有潜在的复发性,患者术后长期随访十分必要。     

Primary CNS lymphomas. Morphology and diagnosis

Diagnostically primary central nervous system lymphomas (PCNSL) have to be differentiated from glioblastoma and brain metastases. Histologically the overwhelming majority of PCNSL is represented by diffuse large B-cell lymphomas, in this series with a BCL6 expression in 80% of the cases detected by immunohistochemistry. Stereotactic biopsy is the method of choice in establishing the definite diagnosis and intraoperative smear cytology will detect the lymphoid blasts. To confirm the B-cell lineage, immunohistochemistry is needed (CD20, CD79a). Small reactive T-lymphocytes and monohistiocytic cells and activated "microglia" are found within and at the periphery of PCNSL foci. The infiltrated brain tissue shows partially pleomorphic reactive astrocytes that can be confused with neoplastic astrocytes, especially in small specimens. In contrast to high-grade gliomas, however, PCNSLs do not show endothelial proliferations. Subtypes or variants of diffuse large B-cell lymphomas can also be observed in cases of PCNSL: the anaplastic variant with large multinucleated tumour cells resembling Reed-Sternberg cells, T-cell rich B-cell lymphoma and intravascular B-cell lymphoma with primary manifestation within the brain or the spinal cord. HIV/AIDS-associated PCNSLs are characterised by large plasmoblastic or small Burkitt-like cells and tumour necrosis. Primary leptomeningeal large B-cell lymphomas do occur very rarely and are diagnosed by cerebrospinal fluid cytology.     

Diagnosis of lymphoma,leukemia, and metastatic tumor involvement of the cerebrospinal fluid by cytology and immunocytochemistry

Fifty-five cerebrospinal fluid (CSF) specimens from 42 patients with suspected meningeal tumor involvement were reviewed. Cytology in conjunction with immunocytochemistry identified 26 CSF specimens as malignant. There were fifteen cases of lymphoma, four cases of leukemia, two cases of carcinoma, and two cases of melanoma. A monoclonal light chain expression was demonstrated in nine out of eleven B cell lymphomas. the three T-cell lymphomas all expressed pan T markers (CD 3) and two the T-helper antigen (CD 4). One patient had meningeal involvement of a true histiocytic lymphoma which was indentified by its large atypical cells which were positive for α-1-anti-trypsin and muramidase. in four patients with a primary diagnosis of acute lymphoblastic leukemia, CSF involvement was confirmed by the demonstration of blasts with CD 10 (cALLA) or light chain restriction. Epithelial or melanocytic markers were demonstrated on the tumor cells in CSF from the remaining four patients. In 29 CSF specimens a diagnosis of reactive lymphocytosis was made using cytomorphology which mostly was characterized by macrophages mixed with small mature lymphoid cells. Immunologic evaluation showed that these mature cells were CD 10 negative T-cells and only few specimens contained polyclonal B-cells. the subsequent clinical course of these patients showed no evidence of CNS malignancy. It is concluded that cytology should be used in conjunction with immunocytochemistry to accurately evaluate CSF specimens from patients with possible malignant meningitis.     

Intravascular lipoleiomyomatosis: a report of two cases

Two cases of intravascular leiomyomatosis (IVL) with histologic features of a lipoleiomyoma (LPL) are reported. Both tumors arose from preexisting uterine leiomyomata. One tumor was found incidentally in a uterus removed for leiomyomata. The other tumor extended up the inferior vena cava into the right side of the heart and presented as a cardiac mass. Although LPL is considered to be a benign lesion, IVL recurs in approximately 10% of reported cases, and must be distinguished from low-grade endometrial stromal sarcoma and leiomyosarcoma with vascular invasion. The combination of features in these cases lends support to the theory that IVL may arise by intravascular extension of a preexisting leiomyoma.     

Primary hepatic lymphoma with spindle cell components: a case report

Diffuse large B-cell lymphoma (DLBCL) with spindle cell components is extremely rare and often misdiagnosed as carcinoma or sarcoma. Here, we present a case of primary DLBCL with spindle cell components arising in the liver, for which a preoperative diagnosis by needle biopsies was unsuccessful. The patient was a 70-year-old man with a continuous cough. Thoracic computed tomography incidentally detected a mass of 5 cm in diameter in his liver. The initial and second needle biopsies from the liver mass were pathologically diagnosed as suspicious for sarcomatoid hepatocellular carcinoma. He underwent an extended left hepatectomy. Histological examination revealed a diffuse or epithelioid arrangement of round and polygonal cells, mixed with the fascicles of spindle-shaped cells. Immunohistochemically, all the morphological types of tumor cells showed positive reactions for a lymphocytic marker (CD45RB) and B-cell markers (CD20 and CD79a). Double-immunostaining revealed that the spindle-shaped tumor cells expressed CD20, but never expressed alpha-smooth muscle actin. Malignant lymphoma with a spindle cell morphology is quite uncommon, and this variant can be a diagnostic pitfall, especially in tiny biopsy specimens. We emphasize that pathologists should be reminded of lymphoma as a differential diagnosis of spindle cell tumors.     

Intravaskuläres Lymphom als Ursache für akutes Abdomen

A 65-year old man presented with acute abdominal pain and fever. The initial diagnosis was small bowel gangrene. Pathology revealed small to large abdominal vessels obliterated by cells of intravascular B-cell-lymphoma (IVL). Visceral IVL involvement is common at autopsy but rarely reported in patients with acute abdomen. The subtype of diffuse large B-cell lymphoma is a rare and aggressive malignancy, which in typical cases is characterized by cephalic or cutaneous manifestation. Few cases showed involvement of large vessels which in combination to fibrin thrombi may lead to infarction of the organ involved. Thus IVL should be considered in cases of ischemic diseases with fever of unknown origin.     

Clinicopathological and immunophenotypical features of canine intravascular lymphoma (malignant angioendotheliomatosis)

Intravascular lymphoma (IVL) is a rare angiotropic large-cell lymphoma in which neoplastic lymphocytes proliferate within the lumina of blood vessels in the absence of a primary extravascular mass or leukaemia. A retrospective review of veterinary medical records identified 17 cases of canine IVL. Spinal cord ataxia (seven dogs), posterior paralysis (one dog), seizures (four dogs) and vestibular disease (three dogs) dominated the clinical presentation. Haemorrhage, ischaemia, and occasional foci of vascular proliferation were found in tissue sections from affected dogs. Vessels, predominantly veins, throughout the body were frequently filled with neoplastic lymphocytes. Splenic involvement occurred in only one of 10 cases examined and bone marrow involvement was absent in four cases examined. Formalin-fixed paraffin wax-embedded tissues from 15 cases were examined immunohistochemically with streptavidin-biotin-horseradish peroxidase and a catalysed signal amplification system. The neoplastic cells were classified in eight cases as T cells (CD3+/IgG-/CD79a-), in one case as B cells (CD3-/CD79a.dim/IgG+), and in the remaining six cases as non-T, non-B (CD3-/IgG-/CD79a-). The clinical and pathological features of canine IVL closely resembled those of the human disease. In striking contrast to human cases, which are most often B-cell lymphomas, the immunophenotypes of the canine IVLs in this series were heterogeneous. The canine IVLs were derived primarily from T cells and non-T, non-B lymphocytes, B cells being found in only a single instance.     

The safety and efficiency of the ultrasound-guided large needle core biopsy of axilla lymph nodes

PURPOSE: To evaluate the safety and efficiency of the Ultrasound (US)-guided large needle core biopsy of axilla lymph nodes. MATERIALS AND METHODS: From March 2004 to September 2005, 31 patients underwent the US-guided core biopsy for axilla lymph nodes. Twenty five lesions out of 31 were detected during breast US, and 6 of 31 cases were palpable. Lymph nodes were classified based on their shape and cortical morphology. The core biopsy of axilla lymph nodes was performed on suspicious lymph nodes found during breast ultrasonography to find out whether the patients had a history of breast cancer or not. Among the 31 patients, 16 patients were associated with breast cancer. The lesion sizes varied from 0.6 cm to 3.3 cm (mean=1.59+/-0.76 cm). US-guided core biopsies were performed with 14 G needles with an automated biopsy gun. Total 3 or 5 specimens were obtained. RESULTS: Among the 31 cases of axilla lymph nodes core biopsies, 11 cases showed malignant pathology. Seven out of 11 cases were metastatic lymph nodes from breast cancer; 2 cases were from primary unknown and 2 cases from lymphomas. On the other hand, 20 histopathologic results of axilla lesions were benign: subacute necrotizing lymphadenitis (n=2), dermatopathic lymphadenitis (n=1), reactive hyperplasia (n=10) and free of carcinoma (n=7). CONCLUSION: The US-guided large needle core biopsy of axilla lesions is safe and effective for the pathological evaluation. The core biopsy is believed to be easy to perform if suspicious lymph nodes or mass lesions are found in the axilla.     

Follicular lymphoma of the salivary gland: a clinicopathological and molecular study of six cases

To clarify the clinicopathologic, immunohistologic, and genotypic features of follicular lymphoma arising from the salivary glands, we examined 20 cases of operatively resected primary salivary gland lymphoma and identified 6 such cases. There were 4 women and 2 men with ages ranging from 38 to 64 years (median 50 years). The tumor arose from the parotid gland in 4 cases and the submandibular gland in the remaining 2. Four patients were stage IE and 2 were stage IIE-1. The median follow-up period was 49 months and all patients were alive and well at the time of going to press. Histologically, 5 patients were follicular lymphoma grade 2, and 1 was grade 3. In all specimens in noninfiltrating salivary gland tissue, there was periductal lymphocytic infiltration near the lymphoma. Moreover, myoepithelial sialoadenitis was noted in 2 lesions. An immunohistochemical study revealed all 6 cases were CD10+, CD79a+, bcl-6+, CD3-, CD5-, CD21-, CD23-, and CyclinD1-. The tumor cells expressed bcl-2 in 3 cases and p53 oncoprotein in 4 cases. Two cases revealed clonal bands with polymerase chain reaction (PCR) assay for the immunoglobulin heavy (IgH) gene. The bcl-2/IgH translocation at the major breakpoint region was detected in 1 case (16%). We found a relatively high incidence of follicular lymphomas (30%) in salivary gland lymphomas. Among the mucosa-associated lymphoid tissue (MALT) system, follicular lymphomas appeared to occur frequently in the salivary glands as well as the duodenum and skin. Moreover, follicular lymphoma arising from the salivary glands appeared to have some of the characteristics of MALT-type lymphoma including indolent prognosis, presence of myoepithelial sialoadenitis, and rarity of the BCL-2 gene rearrangement.     

淋巴结血管内T细胞淋巴瘤1例报道及文献复习

目的　探讨血管内淋巴瘤 (IVL)的临床病理特征。方法　对 1例腹股沟淋巴结IVL临床、病理组织学及免疫表型进行观察分析并复习文献。结果　男性 31岁 ,不明原因高热伴消瘦 5 0天 ,右腹股沟直径 1cm淋巴结 1枚 ,B超示肝脏轻度增大 ,血LDH明显升高伴ESR及转氨酶轻度升高 ,外周血WBC 3 3× 10 7/L ,骨髓像、多种病原及各肿瘤相关抗原检测均无异常。病理活检 :腹股沟淋巴结大部分破坏 ,代之以大量扩张的中小血管 ,腔内充满大量异型淋巴样细胞 ,局部伴管壁、管周浸润并累及结外脂肪组织。瘤细胞免疫表型CD4 5、CD4 5RO、CD3阳性 ,CK、CD6 8、CD79α、CD2 0均阴性 ,血管壁及内皮细胞CD31、CD34阳性。行CHOP化疗后症状缓解 ,现仍在随访中。结论　IVL是一罕见的非霍奇金淋巴瘤 ,好发于中枢神经系统及皮肤 ,其他部位少见 ,绝大数为B细胞型 ,T型罕见 ,以浅表淋巴结活检确诊者尚无报道。临床表现有一定提示性 ,确诊靠组织病理学检查 ,部分病例对化疗敏感 ,但多数病例预后差     

Lymphoproliferative diseases of the orbit and appendages of the eye

The results are available of clinical, morphological, cytological and immunological investigations of orbital lymphomas and lymphomas of appendages of the eye. Malignant lymphoma was detected in 17 patients and reactive lymphoid hyperplasia in 3 patients. All the malignant lymphomas had B-cell phenotype. By cell composition, MALT-lymphoma is more polymorphic than lymphoma from mantle zone cells and lymphoma from small lymphocytes and centro follicular lymphoma. The conjunctive is affected primarily with lymphoma from marginal zone cells or mantle zone cells. As a rule, this is a primary local lesion. Other variants of orbital lymphoma and lymphoma of the eye appendages develop more often as secondary lesions in systemic disease and are characterized by more aggressive course. The key in differential diagnosis of reactive lymphoid hyperplasia and small cells lymphomas is immunophenotyping, especially at initial stages of the tumor process.     

Morphologie neurologischer Komplikationen bei der intravaskulären Lymphomatose

Intravascular lymphomatosis (IVL) is a rare lymphoproliferative disease characterized by intravascular growth of lymphoma cells in small vessels. Most frequently, its first manifestations occur in the central nervous system or skin. Based on autoptical findings in a 68-year-old-man with IVL, the pathological morphology in the central nervous system is compared to the course of neurological symptoms. The disease could not be diagnosed during his lifetime. The spectrum of neurological deficits can be explained histopathologically by occlusive intravascular aggregations of lymphomatous cells in small vessels of the spinal leptomeninges and nerve roots causing perfusion deficits and areas of ischemic necrosis of up to 4 mm in diameter in the medulla. Aggregations of lymphoma cells in the vessels of other organs are also found, but did not result in clinical symptoms. In reference to the present case, a survey of other literature reports on IVL with neurological and psychiatric manifestations is given. In patients with this condition, even an invasive biopsy has to be considered in order to make the correct diagnosis at an early clinical stage.     

Primary low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma with polypoid appearance. Polypoid gastric MALT lymphoma: A clinicopathologic study of eight cases

In the current study, we report eight cases with primary low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma endoscopically characterized by polypoid lesions in order to highlight their clinicopathologic significance. Four patients were male, their ages ranging from 40 to 78 years old. The resected specimens revealed a histology of low-grade MALT lymphoma characterized by dense lymphocytic infiltration predominantly in the submucosa and a relatively monotonous proliferation of centrocyte-like cells with reactive follicles and infrequent lymphoepithelial lesions. The tumor cells were of CD5-, CD10-, CD20+, BCL2+ and cycline D1- phenotype, and showed a monoclonal rearrangement of immunoglobulin heavy chain genes in the five of six cases examined. Interestingly, Helicobacter pylori (H. pylori) was detected in three (37.5%) of the eight patients, which was significantly lower than previous reports. Two of the H. pylori-positive cases initially underwent H. pylori eradication, but showed no change in their lymphomas after the cure of H. pylori infection. The clinicopathologic findings of the present cases appeared to closely resemble those of colorectal MALT lymphoma with a polypoid appearance and few association of H. pylori infection in their pathogenesis. These gastric polypoid cases may merit separate consideration because of the therapeutic problems they pose.     

Mediastinal lymphangiomatosis coexisting with occult thymic carcinoma

Mediastinal lymphangiomatosis in a 70-year-old woman was diagnosed on a medical checkup. The tumor was resistant to sclerotherapy with OK432 or bleomycin. The patient continued on a downhill course and died approximately 3 years after the initial diagnosis. Autopsy revealed a large tumor mass occupying the anterior mediastinum and firmly adhered to the pericardium and the pleura. The tumor consisted of two intermingled lesions: dilated vessels lined with D2-40-positive lymphatic endothelium and CD5-positive atypical cell nests with focal keratinization. The former was diagnosed as lymphangiomatosis and the latter as thymic squamous cell carcinoma. Vascular endothelial growth factor (VEGF)-C, a growth factor for lymphatic endothelial cells, was expressed by the carcinoma, and VEGF-C receptor was expressed by the endothelium of lymphangiomatosis. These findings suggested that VEGF-C derived from the thymic carcinoma induced the lymphangiomatosis lesion in a paracrine manner.     

Epstein‐Barr virus frequency in primary central nervous system lymphomas in Turkey

Primary central nervous system (CNS) lymphomas are rare neoplasms which are usually not associated with Epstein‐Barr virus (EBV) in immunocompetent patients. The aim of this study was to investigate the incidence of EBV in primary CNS lymphomas in the Turkish population. Thirty‐two primary CNS lymphomas diagnosed according to the WHO 2008 criteria were included in this study. The presence of EBV small ribonucleic acids was investigated by in situ hybridization using EBV encoded small RNA oligonucleotides. The expression of CD10, Bcl‐6, MUM‐1/IRF‐4, Bcl‐2, and Ki‐67 were evaluated using immunohistochemistry. The patient cohort included 20 male patients and 12 female patients with a median age of 53.5 years (range 13–75). Seven (22%) of cases were classified as germinal center (GC) and 25 (78%) cases as non‐GC phenotype according to the Hans criteria. Twenty‐six (81%) of the cases showed strong Bcl‐2 expression and the median Ki‐67 index was 78%. EBV expression was observed in four primary CNS lymphoma cases (12.5%). Most primary CNS lymphomas show non‐GC phenotype with high Bcl‐2 expression and high proliferative rate. The incidence of EBV in primary CNS lymphomas from Turkey appears to be higher than that observed in the Western countries.     

Diagnostic utility of programmed cell death ligand 1 (clone SP142) in mediastinal composite lymphoma: A report of two cases

Composite lymphoma is a well‐known diagnostic entity exhibiting the synchronous occurrence of two or more distinct types of lymphomas in the same specimen. Here we report two patients, a 14‐year‐old female (Case 1) and a 45‐year‐old male (Case 2), with mediastinal composite lymphoma, comprising nodular sclerosis classic Hodgkin lymphoma (NSCHL) and primary mediastinal large B‐cell lymphoma (PMBL). Both patients had a mediastinal mass, and manifested two different histologic components in the same biopsy, one characteristic of NSCHL and the other PMBL. The NSCHL areas included Hodgkin and Reed–Sternberg (HRS) cells with typical immunophenotypic features (CD30‐positive and CD20‐negative), whereas the sheets of large tumor cells characteristic of PMBL were strongly and uniformly CD20‐positive. Interestingly, although both cases showed neoplastic PD‐L1 (nPD‐L1) positivity on the HRS cells of NSCHL, they differed regarding nPD‐L1 expression on the PMBL tumor cells. In Case 1, the nPD‐L1‐negative PMBL component was anatomically situated outside the NSCHL lesion. On the other hand, in Case 2, the nPD‐L1‐positive PMBL component was characterized by transitional or continuous areas with the NSCHL component. These findings suggested that nPD‐L1 expression may define two subtypes of PMBL that are more similar to or distinct from classic Hodgkin lymphoma.     

A Case of Pulmonary Adenocarcinoma with Sarcomatous Elements Initially Manifested as a Submucosal Tumor of the Stomach

A case of pulmonary adenocarcinoma, which was initially manifested as a gastric submucosal tumor, is presented. Endoscopy showed a submucosal tumor in the fundic region in a 79-year-old Japanese woman. Initial biopsy specimens of the stomach revealed atypical spindle cell proliferation, suggesting primary leiomyosarcoma of the stomach. However, biopsy specimens obtained one year later were diagnosed as malignant lymphoma or malignant histiocytosis of the stomach. Autopsy revealed a large necrotic lesion in the right S₈ region with metastases in multiple organs. Microscopy demonstrated well to moderately differentiated adenocarcinoma containing spindle or pleomorphic sarcomatous elements. Metastatic nodules including the gastric tumors all showed sarcomatous elements with no epithelial component. Immunohistochemistry showed positive reactions for keratin, epithelial membrane antigen, and carcinoembryonic antigen in areas of carcinoma, whereas most of the sarcomatous elements revealed no positivity for any of the antibodies used, except for focal keratin and EMA positivity in the primary site. This is a rare case of pulmonary adenocarcinoma with sarcomatous elements discovered as a gastric tumor at initial diagnosis, resulting from metastasis of the sarcomatous element in the submucosa.