Histiocytic sarcoma of the parotid gland region

Histiocytic sarcoma (HS) is a malignant neoplasm showing the morphological and immunophenotypic features of mature histiocytes. Reported herein is a case of HS of the parotid gland region. A 53-year-old woman noticed a swelling of the right preauricular area. Preoperative fine needle aspiration cytology showed an admixture of pleomorphic atypical cells and mature lymphocytes. She underwent total parotidectomy. Grossly, the tumor was located at the parotid gland to subcutaneous tissue, and showed infiltrative growth with massive necrosis and hemorrhage. Microscopically, the tumor was composed of marked pleomorphic cells with eosinophilic cytoplasm. Bizarre multinuclear giant cells were scattered and intermingled. Tumor cells were positive for CD68 (KP-1 and PG-M1), CD163, S-100 protein, CD1a, CD4 and CD31, but negative for CD3, CD20, CD21, CD79a, DEC205 and langerin, immunohistochemically. Monoclonal proliferation of B cells was not confirmed on polymerase chain reaction for IgH. The patient had recurrent lesions in the pelvis and stomach 5 months after parotidectomy and died of the disease 10 months after the operation.     

Leiomyosarcoma of the heart and its pulmonary metastasis, both with prominent osteoclast-like multinucleated giant cells expressing tartrate-resistant acid phosphatase activity

An autopsy case of cardiac leiomyosarcoma and its pulmonary metastasis, both with osteoclast-like multinucleated giant cells (OMGC) mimicking the so-called giant cell variant of malignant fibrous histiocytoma (MFH), is reported. The patient, a 70-year-old male, was admitted for sudden dyspnea. Extensive work-up established only a left atrial tumor mass. Three months after admission, the patient developed multiple intracranial and pulmonary metastases, followed by a worsening clinical course characterized by semicoma and dyspnea, and subsequently died 6 months after the onset of his symptoms. At subsequent autopsy, the left atrial polypoid tumor was found to have invaded destructively to the left half of the cardiac wall. Histology of the cardiac tumor revealed a bimorphic sarcoma in which a poorly differentiated leiomyosarcoma comfirmed by histologic and immunohistochemical findings was juxtaposed to a small nodule with features closely mimicking giant cell MFH. The pulmonary metastatic nodules exhibited features that were entirely indistinguishable from giant cell MFH except for the fact that a minority of polymorphic cells manifested myogenic differentiation. We believe that such a MFH-like pattern represents a pleomorphic form of leiomyosarcoma rather than a dedifferentiated one. The OMGC within the MFH-like component coexpressed CD68 and tartrate-resistant acid phosphatase activity.     

Coexistence of renal epithelioid angiomyolipoma and clear cell carcinoma in patients without tuberous sclerosis

Renal epithelioid angiomyolipoma (EAML) is a rare but distinct variant of angiomyolipoma, closely simulating renal cell carcinoma or sarcoma both clinically and histopathologically. This report presents an unusual case of unilateral simultaneous renal EAML and renal clear cell carcinoma. A 52-year-old man without any sign of tuberous sclerosis had a complaint of 6-month history of pain in left renal area and had macroscopic hematuria twice within the recent 1 month. Computed tomography showed the presence of 2 masses in the upper and lower portion of the left kidney. The patient underwent left radical nephrectomy. Histological examination revealed the upper mass was composed of medium to large epithelioid cells with clear or eosinophilic cytoplasm and numerous giant multinucleated cells. Adult-appearing adipose tissue and coagulative necrosis could also be observed focally in the mass. Immunohistochemically, the tumor cells in the upper mass showed positive reactions to actin, HMB-45, Melan-A, and CD68 but negative reactions to pan-cytokeratin (pan-CK), epithelial membrane antigen, and CD10. However, the lower mass was composed of diffusely monomorphic clear cells with strongly immunoreactive for pan-CK, vimentin, and CD10, whereas without expression for HMB-45 and actin. The patient showed no evidence of recurrence or metastasis during 1-year postoperative following-up period. To the authors' knowledge, this is the first report of coincidental renal EAML and clear cell carcinoma in the same kidney. Unlike classic triphasic angiomyolipoma, adjuvant therapy after resection should be considered for renal EAML because of its malignant potential, more aggressive behavior and poor prognosis.     

PG-M1: A New Monoclonal Antibody Directed against a Fixative-Resistant Epitope on the Macrophage-Restricted Form of the CD68 Molecule

A new anti-macrophage monoclonal antibody (PG-M1) was produced by immunizing BALB/c mice with fresh spleen cells from a patient with Gaucher's disease. PG-M1 reacts strongly with a fixative-resistant epitope of an intracytoplasmic molecule, selectively expressed by virtually all macrophages of the human body. Although attempts to immunoprecipitate the molecule recognized by PG-M1 have failed so far, the reactivity of the antibody with COS-1 and WOP cells transfected with a human complementary DNA clone encoding for the CD68 antigen suggests that PG-M1 is a new member of the CD68 cluster. However, unlike other CD68 antibodies (KP1, EBM11, etc.), which react with both macrophages and myeloid cells, PG-M1 detects a fixative-resistant epitope on the macrophage-restricted form of the CD68 antigen. In 957 routinely fixed, paraffin-embedded samples, PG-M1 showed a more restricted reactivity with elements of the monocyte/macrophage lineage than the previously described monoclonal antibodies MAC-387 (anti-calgranulins), KP1 (CD68) and Ki-M1P. Among hematological malignancies, PG-M1 only labels acute leukemias of M4 and M5 type and rare examples of malignant histiocytosis/true histiocytic sarcoma. In contrast, acute leukemias of the M1, M2, M3, M6, M7, and L1-L3 types, non-Hodgkin's lymphomas, and Hodgkin and Reed-Sternberg cells of Hodgkin's disease are consistently PG-M1-negative. In the daily diagnostic practice, PG-M1 seems to be particularly valuable for the diagnosis of myelomonocytic or monocytic leukemia and neoplasms of true histiocytic origin in routine paraffin sections.     

Malignant phyllodes tumor of the breast with osteoclast-like giant cells: a case report

Breast tumors, particularly of stromal origin, containing multinucleated osteoclast-like giant cells (OLGC) are rarely reported in the literature. We report here the first case of a malignant phyllodes tumor associated with OLGC occurring in a 43 year-old African woman who presented with a painful palpable mass of the outer upper quadrant of the right breast. After surgical excision, histological examination showed a malignant phyllodes tumor in which the stromal component displayed evident sarcomatous changes and was densely populated with benign multinucleated OLGC. These cells expressed the CD68 histiocytic marker. No evidence of osseous or cartilaginous differentiation was seen throughout the lesion. This lesion ressembles giant cell tumor of bone. However, the nature of the OLGC is not well precised yet.     

Histiocytic sarcoma - a case with evenly distributed multinucleated giant cells

Histiocytic sarcoma is an uncommon neoplasm of mature histiocytes with a poor clinical outcome. We report a case of a true histiocytic sarcoma with prominent and evenly distributed multinucleated giant cells that mimics a giant cell tumor of soft tissue. The tumor was located between the appendix, right ovary, and the terminal ileum with severe adhesion. The liver and spleen were not enlarged. Grossly, the tumor appeared grayish white, solid, and soft. Microscopically, polygonal mononuclear tumor cells aggregated to form somewhat epithelioid nests, which occasionally showed coagulative necrosis. Prominent and evenly scattered giant cells were present in all sections. In addition, tumor cell infiltration was noted in regional lymph nodes. The tumor cells were positive for lysozyme, CD68, CD163, and negative for T- and B-cell lineage markers, follicular dendritic cell, megakaryocytic, epithelial, muscular, and melanocytic markers, CD1a and CD30. This case posed great difficulty in clinical and pathological diagnoses. Gross pictures, microscopic findings, and extensive immunostains are important for the differential diagnosis.     

February 2002: 29-year-old woman with a skull mass for 2 months

A 29-year-old woman had a 2-month history of an enlarging lesion over her left frontal bone following minor trauma. CT scan showed an osteolytic lesion with an overlying soft tissue mass, thought to be an unhealed skull fracture with pseudomeningocele. Left frontal craniotomy revealed a soft tissue mass, which was resected. Histologic examination revealed multinucleated giant cells mixed with Langerhan's cells that showed the characteristic "coffee bean nuclei." Eosinophils were scant. Immunostaining for CD1a and S100 revealed strong positive staining primarily in the Langerhans' cells while giant cells and inflammatory cells were negative. Immunostaining for CD68, in contrast, stained the osteoclast-like giant cells and macrophages. Electron microscopy confirmed the presence Birbeck granules. The final diagnosis was Langerhans' cell histiocytosis (histiocytosis X) of the skull.     

Giant cell tumor of bone. A cytologic study of 24 cases

Twenty-three patients with radiologic diagnoses of giant cell tumor of bone underwent fine needle aspiration cytology and needle biopsy for tissue diagnosis before curettage or resection. One patient had two tumors, making a total of 24 cases. The accuracy of the cytologic diagnosis was compared with that of tissue biopsy. Cytologically there were mononucleated and multinucleated cells. The former often occurred in clusters or, less often, were dispersed. They had spindle or plump cell bodies with moderate amounts of cytoplasm and well-defined cytoplasmic membranes. The oval nuclei demonstrated fine, evenly distributed chromatin and small nucleoli. The multinucleated cells were osteoclastlike and were associated with the clusters of mononucleated cells or lying freely. They had a well-demarcated cytoplasm and contained from a few to several dozen monomorphic nuclei. Cytologic diagnosis was made in 20 of 24 cases, and histologic diagnosis was made in 21 of 24. Insufficient diagnostic material for cytology was the reason for failure in 4 cases. This was attributed to faulty technique (2 cases), cystic change (1 case), and massive necrosis (1 case). As other benign and malignant bone tumors may contain benign giant cells, cytologic or histologic findings alone are not diagnostic of giant cell tumor of bone, but should be complemented with the clinicoradiologic findings. Aspiration cytology is as accurate as tissue needle biopsy, may be of high diagnostic value in deeply located lesions not amenable to cutting needle biopsy, and should be done with full knowledge of the clinicoradiographic information.     

Atypical decubital fibroplasia with unusual histology

A case of atypical decubital fibroplasia with unusual histology arising in the buttock of a 68-year-old bed-ridden male in presented. The lesion measuring 5.4 cm in greatest dimension was histologically characterized by a proliferation of fibroblasts with oval to spindle nuclei and dense fibrous stroma with focal hyalinization and calcification. Ganglion-like fibroblastic cells and multinucleated giant cells of osteoclast type were also observed. There were numerous elastic fibers within and adjacent to the proliferating stromal cells. The proliferating stromal cells were positive for vimentin and collagen type IV but negative for CAM 5.2, epithelial membrane antigen, desmin, alpha-smooth muscle actin, muscle actin, HHF35, S-100 protein and CD34. Ultrastructurally, they were of a fibroblastic nature. The hypercellularity, lack of zones of fibrinoid necrosis, lack of lobulation and the presence of multinucleated giant cells were different from the originally described lesion. This condition represents a variant of atypical decubital fibroplasia. Pathogenic factors of this lesion are considered to be chronically repeated pressure and associated intermittent ischemia. The recognition of the lesion and its distinction from a sarcoma is essential.     

Primary giant cell malignant fibrous histiocytoma of the lung: A case report

A rare case of malignant fibrous histiocytoma of giant cell type originating in the lung of a 46-year-old woman is presented. The patient complained of having a cough that had lasted for a few weeks. A chest X-ray photograph showed a tumor shadow on the left lung. Histological and cytological examination of the biopsy specimen revealed that the tumor was a kind of sarcoma. An operative procedure was selected because of tumor invasion into the trunk of the left pulmonary artery, which was discovered on computed tomography examination, and because metastatic tumor was excluded clinically. The tumor was almost encapsulated and 6 x 6 x 6 cm in size; however, it also showed invasion into the pulmonary artery and bronchial lumen. A histological survey of the tumor showed a wide range of patterns such as fibrous, pleomorphic, fascicular and osteoclast-like giant cell figures; however, the osteoclast-like giant cell area was predominant. Immunohistochemically, the tumor cells were positive for vimentin, CD68 for histiocytic marker and alpha1-antichymotrypsin, and negative for keratin, epithelial membrane antigen, S-100 protein, MT-1, desmin, myoglobin and lysosome. No primary tumor was found clinically in any part of the patient's body at 2 and 4 months after operation. Consequently, she was diagnosed as having primary giant cell malignant fibrous histiocytoma of the lung.     

A histiocyte-specific marker in the diagnosis of malignant fibrous histiocytoma. Use of monoclonal antibody KP-1 (CD68)

KP-1 (CD68) is a recently described monoclonal antibody to a cytoplasmic epitope present on tissue histiocytes and macrophages. To determine the specificity and sensitivity of this marker in the evaluation of cases of malignant fibrous histiocytoma (MFH), this reagent and a panel of commercially antibodies were used to stain formalin-fixed paraffin sections from 25 cases of MFH and 25 other tumors, including a variety of soft-tissue sarcomas. Eighteen of 25 cases of MFH stained for KP-1 (72%), whereas all other tumors were negative, including 12 cases of pleomorphic soft-tissue sarcoma other than MFH. The percentage of tumor cells staining for KP-1 varied. In 11 cases KP-1 was only focally present, but staining was of a high intensity and associated with minimal nonspecific or background staining. Pleomorphic histiocytic cells and spindle cells from storiform tumors were strongly decorated with antibodies to KP-1 in most cases, and antigen also was present on tumor giant cells. Although alpha-1-antitrypsin and alpha-1-chymotrypsin stained a higher percentage of cases of MFH (92%), immunoreactivity for these markers also was noted in other tumors. Because of its specificity as a histiocyte marker, KP-1 is a useful component in a panel of antibodies for the characterization of soft-tissue sarcomas and the diagnosis of MFH.     

Myofibroblastoma of the breast with diverse histological features

 We report two cases of myofibroblastoma with unusual pathological features, in a 66-year-old woman and a 49-year-old man. Both tumours were unilateral, grossly nodular and well circumscribed, but not encapsulated. The lesions were made up of bipolar spindle cells arranged in fascicular clusters separated by bands of hialinized collagen; one included several islands of mature cartilage next to fat cells. The other contained atypical mononucleated and multinucleated giant cells. No mitotic figures were observed. Immunohistochemically, both tumours showed strong and diffuse cytoplasmic staining for vimentin and CD 34 and focal positivity for alpha-smooth muscle actin, and both were negative for cytokeratins, CD 68, Ham 5, 6, Mac 387, and S-100 protein. Desmin was positive in one case. Ultrastructural study revealed populations composed of fibroblastic cells without signs of myofibroblastic differentiation in one case; the second featured abundant undifferentiated mesenchymal cells with myofibroblastic differentiation. Both patients remain disease-free 38 and 36 months after lumpectomy. Received: 28 September 1998 / Accepted: 10 February 1999     

Ductal adenocarcinoma of the pancreas with huge cystic degeneration: a lesion to be distinguished from pseudocyst and mucinous cystadenocarcinoma

Cystic neoplasms of the pancreas are rare and often mistaken for pseudocyst by imaging studies and macroscopic examination. We describe an unusual tumor of the pancreas composed of a mural nodule of anaplastic carcinoma arising from a huge ductal adenocarcinoma undergoing cystic degeneration. The cyst measured 27 x 13 x 4 cm. Light microscopy showed that the cyst was partly lined by a single layer of cuboidal to columnar tumor cells with focal mucin production and was surrounded by hyalinized connective tissue. Most lining epithelial cells were absent owing to extensive degenerative process. Immunohistochemical studies showed positive staining of cytokeratin and vimentin for pleomorphic giant tumor cells, which were negative for leukocyte common antigen (CD45), KP-1 (CD68), epithelial membrane antigen (EMA), and carcinoembryonic antigen (CEA). The ductal adenocarcinoma stained strongly positive for cytokeratin and EMA, and negative for vimentin, CD45, CD68, and CEA. The clinical course of the current case was extremely poor and the prognosis resembled that of an anaplastic carcinoma. Therefore, we like to emphasize the importance of complete excision and extensive sampling of any cystic neoplasms in the pancreas including those with large cystic component to avoid missing the malignant elements.     

Abnormal Nuclear Structures (Micronuclei,Nucleoplasmic Bridges,and Nuclear Buds) in a Pleomorphic Giant Cell Carcinoma of the Stomach

A rare case of pleomorphic giant cell carcinoma of the stomach in a 70-year-old man is reported. Characteristic microscopic findings included a general lack of architectural cohesiveness, aggregates of mononucleated or multinucleated giant cells, extensive areas of coagulative necrosis, and numerous mitoses. Immunohistochemically, tumor cells displayed cytoplasmic immunoreactivity for cytokeratin AE1/AE3 as well as overexpression of p53 and Ki-67. Electron microscopy revealed paranuclear tonofilaments bundles in giant cells confirming their epithelial nature. Furthermore, giant cells contained two or more nuclei with heterogeneous size, nucleoplasmic bridges, nuclear buds, and micronuclei. Similar abnormal nuclear structures have been closely related to breakage-fusion-bridge type of mitotic disturbances in tumor cell lines, and have not been previously reported in a human tumor.     

Abnormal nuclear structures (micronuclei, nucleoplasmic bridges, and nuclear buds) in a pleomorphic giant cell carcinoma of the stomach

A rare case of pleomorphic giant cell carcinoma of the stomach in a 70-year-old man is reported. Characteristic microscopic findings included a general lack of architectural cohesiveness, aggregates of mononucleated or multinucleated giant cells, extensive areas of coagulative necrosis, and numerous mitoses. Immunohistochemically, tumor cells displayed cytoplasmic immunoreactivity for cytokeratin AE1/AE3 as well as overexpression of p53 and Ki-67. Electron microscopy revealed paranuclear tonofilaments bundles in giant cells confirming their epithelial nature. Furthermore, giant cells contained two or more nuclei with heterogeneous size, nucleoplasmic bridges, nuclear buds, and micronuclei. Similar abnormal nuclear structures have been closely related to breakage-fusion-bridge type of mitotic disturbances in tumor cell lines, and have not been previously reported in a human tumor.     

Fine-needle aspiration cytology of osteoclastic giant-cell tumor of the pancreas.

Osteoclastic giant-cell tumor (OGCT) of the pancreas is a rare tumor. We present the fine-needle aspiration (FNA) and bile cytology findings of an OGCT arising in the head of the pancreas in a 72-yr-old male, along with immunocytochemical studies that were done on the cytologic material. The smears showed numerous giant cells with clustered, overlapping, uniform, bland-appearing nuclei with prominent nucleoli consistent with osteoclastic-type multinucleated giant cells. A second population of mononucleated cells appearing singly or in groups having similar nuclear features was also present. Immunocytochemical studies performed on the FNA and bile duct fluid material demonstrated positive staining of the malignant cells for vimentin, alpha-1 antichymotrypsin, and alpha-1 antitrypsin and negative staining for high- and low-molecular-weight cytokeratin, pooled monoclonal cytokeratin, epithelial membrane antigen, and carcinoembryonic antigen. Although not definitive, these studies are supportive of a mesenchymal-stromal histogenesis of this unusual pancreatic malignancy.     

Dumbbell-shaped leiomyosarcoma of the inferior vena cava with foci of rhabdoid changes and osteoclast-type giant cells

An inferior vena cava (IVC) tumor was incidentally found in a 67-year-old Japanese man. The resected tumor was lobulated and multinodular, measuring 14.0 x 6.5 x 7.0 cm, showing a dumbbell-shaped appearance with a central constriction. The tumor showed both intra- and extra-luminal growth. The tumor was primarily composed of well-differentiated leiomyosarcoma. Spindle tumor cells in the well-differentiated area were positive for vimentin, muscle actin, alpha-smooth muscle actin, and desmin. Foci of rhabdoid cells and osteoclast-type multinucleated giant cells were also found. Rhabdoid cells ultrastructurally had paranuclear aggregates or whorls of intermediate filaments that were positive for vimentin, low molecular weight cytokeratin, and desmin. Osteoclast-type multinucleated giant cells were positive for only CD68 antigen, suggesting a reactive histiocytic lineage. To the best of our knowledge, this is the first case of IVC leiomyosarcoma accompanied by both rhabdoid tumor cells and osteoclast-type reactive multinucleated giant cells. These unusual features should be kept in mind in the diagnosis of dumbbell-shaped retroperitoneal tumors that involve the IVC.     

Clinicopathological features of angiomatoid fibrous histiocytoma: a series of 21 cases with variant morphology

We analyzed the clinicopathological features of angiomatoid fibrous histiocytoma (AFH) in 21 cases with emphasis on variant morphology. In our series, ten patients were male and eleven were female. The patients’ mean age was 26.9 years old. Tumors were located on the lower limbs in eight cases, upper limbs in three, trunk in five, head and neck in four, and trachea in one. Microscopically, thirteen cases were characterized by typical AFH. Tumor cells showed marked tumor pleomorphism with giant hyperchromatic nuclei in two cases. Mitotic figures (2-3/10HPF) were found in two cases. Focal necrosis was found in one case. A number of multinucleated giant cells were found in two cases. Two cases showed obvious myxoid change in the stromal. Prominent sclerosing changes in the stromal component were found in two cases. Immunohistochemistry staining showed tumor cells were positive for EMA, desmin, and CD68. Five cases demonstrated the presence of rearrangement of the EWSR1 gene by FISH detection. Only two patients had tumor recurrence at 3 and 6 months after tumor resection, respectively. In conclusion, AFH has variant histological patterns. The differential diagnosis includes inflammatory myofibroblastic tumor, aneurysmal fibrous histiocytoma, follicular dendritic cell tumor, and metastatic tumor of lymph node.