Visceral leishmaniasis: II. Histiocyte ultrastructure in bone marrow associated with low level of parasitaemia and mimicking malignant histiocytosis

The ultrastructural features of histiocytes in the bone marrow (BM) were studied in a febrile, splenomegalic and pancytopenic Sudanese patient who was diagnosed by one of us as visceral leishmaniasis (VL) associated with low level of parasitaemia and mimicking malignant histiocytosis (MH). Serial thick (STS) and ultrathin (SUT) sections showed that the BM was hypercellular and markedly infiltrated by large histiocytes with prominent phagocytosis. A thorough examination of various ST and UT section revealed only a single, typical Leishman-Donovan body. At transmission electron microscopy (TEM) level, two principal types of histiocytic cells were identified: Type I, subdivided into two subtypes, were actively phagocytic histiocytes (PH) with large digestive vacuoles and primary lysosomes; type II were nonphagocytic histiocytes (nPH) with primary lysosomes only. The rate of PH to nPH ws 7:2 in plastic STS. The interaction between the PH and ingested cells is described. Both types of cell were morphologically similar to previously described malignant histiocytic cells. However, this study showed a better characterization of PH during VL.     

17-KS sulfate as a biomarker in health and disease

OBJECTIVE: To attempt to distinguish cases of true malignant histiocytosis from the clinical syndromes of so-called malignant histiocytosis with use of recent methods. DESIGN: We retrospectively studied the laboratory data and clinical course of Mayo patients who had clinical syndromes of so-called malignant histiocytosis and reviewed available paraffin-embedded tissue specimens to identify the nature of the malignant cells. MATERIAL AND METHODS: After elimination of cases of infection-associated hemophagocytic syndrome, we reviewed and studied seven cases of so-called malignant histiocytosis in patients who had undergone assessment at Mayo Clinic Rochester between 1973 and 1993. We identified histiocytes by using current morphologic, cytochemical, and immunohistochemical methods. The clonal nature of the malignant cells was identified with morphologic, cytogenetic, and molecular genetic studies. RESULTS: Only one of the seven cases had a true histiocytic origin. The malignant cells were T cells in three other cases (the cells were also CD30+ in two cases), CD30+ cells only in one case, epithelial cells in one case, and an undetermined cell type (stained positively only with antitrypsin) in one case. CONCLUSION: True malignant histiocytosis is an exceedingly rare disease, and only a few reports have clearly identified the histiocytic origin of the malignant cells. Previously, the lack of monoclonal antibodies specific to histiocytes and the absence of techniques for performing molecular genetic studies on paraffin-embedded tissue prevented the study of such cases. With newer techniques cases of true malignant histiocytosis can now be identified.     

Imaging of quantal calcium release in the inositol 1,4,5-trisphosphate-sensitive organelles of permeabilized HSY cells

Twenty-nine cases of histiocytic neoplasms, some resembling juvenile xanthogranuloma (JXG) and others resembling reticulohistiocytoma (RH), were evaluated. Immunohistochemical stains were performed. In this series, seven cases were identified that expressed S-100 protein positive cells. The S-100 positive cells were predominantly large mononuclear and multinucleated histiocytes with eosinophilic cytoplasm, but also in some cases xanthomatous cells and Touton giant cells. These cells also expressed a positive reaction for vimentin, KP-1, and Factor XIIIa. There was no reactivity observed for monoclonal antibody 010(CD1a). A positive reaction for S-100 protein is conventionally accepted as a useful differentiating feature between histiocytosis X and non-X histiocytosis such as JXG and RH. The conflicting results of the immunohistochemical stains in the lesions we studied could be potential pitfalls in diagnosing histiocytic neoplasms.     

Orbital involvement in 'sinus' histiocytosis. A report of four cases

Sinus histiocytosis is a newly recognized benign disease affecting mainly children and young adults and usually having a protracted clinical course that is relatively unaffected by therapy. This paper describes four additional patients who had orbital involvement initially and reviews the salient clinical and histopathologic features of this entity. The outstanding clinical feature is cervical lymphadenopathy. Associated findings include low-grade fever, anemia, leukocytosis, and elevated IgG levels. A small percentage of patients develop proptosis with palpable orbital tumors. Such patients may not have appreciable lymphadenopathy. Progressive proptosis may lead to exposure keratitis, corneal ulceration, endophthalmitis, and loss of the eye. Histopathologically, the lymph nodes and orbital mass show a proliferation of large histiocytes intermixed with a variable proportion of lymphocytes and plasma cells. Lymphocytes and occasionally other cells derived from the hematopoietic system are commonly seen within the cytoplasm of the histiocytes.     

Fibro-osseous, osseous, and cartilaginous lesions of the orbit and paraorbital region. Correlative clinicopathologic and radiographic features, including the diagnostic role of CT and MR imaging

Fibro-osseous and cartilaginous lesions of the orbit and facial region share overlapping clinical, radiologic, and pathologic features that may lead to diagnostic confusion and possible misdiagnosis. The value of imaging studies in the histopathologic diagnosis of these lesions cannot be overemphasized. The histopathologic diagnosis of such lesions should not be rendered in the absence of radiographic correlation.     

Colonic histiocytic neoplasm mimicking malignant histiocytosis and presenting as intussusception

It is now apparent that distinction between the so-called malignant histiocytosis and lymphoma can be made using panels of established immunohistochemical markers and/or genotypic analysis. Many, if not all, of the previously diagnosed cases of malignant histiocytosis have been shown to be of lymphoid, rather than histiocytic, lineage. We report a rare case of colonic histiocytic neoplasm accompanied by a lymphoreticular dissemination that mimicked that of malignant histiocytosis. In addition, barium studies and computed axial tomography confirmed an intussusception that subsequently developed. The histiocytic nature of the neoplastic cells was supported by immunohistochemical, ultrastructural, and cytochemical studies. To our knowledge our case may represent the fifth documented case of a histiocytic malignancy reported in the literature. The relationship among the various cases will be discussed as well as the significance of the focal S-100 immunoreactivity observed in the present case.     

Postarthroplasty histiocytic lymphadenopathy in gynecologic oncology patients. A benign reactive process that clinically may be mistaken for cancer

BACKGROUND: A distinctive histiocytosis occurs in the regional draining lymph nodes after large joint replacements, resulting in lymphadenopathy that may mimic cancer both grossly and microscopically. Postarthroplasty histiocytic lymphadenopathy has most often been observed in males during surgery for prostate cancer. METHODS: The authors present three examples of postarthroplasty histiocytic lymphadenopathy that occurred in gynecologic oncology patients. We studied the clinical, histologic, and immunohistochemical features of all three cases and the ultrastructure of one of them. RESULTS: Most involved lymph nodes were enlarged, but histiocytosis was also seen in normal sized lymph nodes. Microscopically, histiocytes with abundant granular cytoplasm were present in the lymph node parenchyma, and, to a lesser extent, in the sinuses. Normal lymph node architecture was variably effaced and the histiocytic infiltrate extended focally into the perinodal tissue. Small, black metal particles were present in the histiocytes in every case. Birefringent polyethylene particles were a prominent finding in all three cases as confirmed by positive modified oil red O staining, and, in one case, by electron microscopy. The histiocytes were strongly immunoreactive for CD68, but immunostains for S100 protein, MAC 387, and cytokeratin were negative. CONCLUSIONS: Enlargement of the lymph nodes in cancer patients who have had large joint replacements may be due to a benign histiocytosis rather than to metastatic cancer. The histologic features of the lymphadenopathy are distinctive and recognizable in routine histologic preparations. Polyethylene wear particles shed from joint prostheses are the most common substances in the histiocytes and are the most likely cause of the histiocytosis.     

Virus-associated hemophagocytic syndrome. Diagnosis and treatment

Virus-associated haemophagocytic syndrome (VAHS) is a rare disease characterized by fever, splenomegaly, cytopenia and histiocytic proliferation with haemophagocytosis in the reticuloendothelial system. The clinical course of VAHS can be dramatic and the prognosis is often poor. The pathogenesis of VAHS is not well understood. Many believe that viral infection provokes an abnormal immune response in predisposed individuals leading to hyperactivation of Th1 helper cells, macrophage proliferation and secretion of large amounts of cytokines. The resultant hypercytokinaemia may be responsible for the clinical and biochemical manifestations of VAHS. In this article the clinical features, presumed pathogenesis, diagnostic criteria and treatment of VAHS are discussed.     

Disseminated malignant histiocytosis in a golden retriever: clinicopathologic, ultrastructural, and immunohistochemical findings

Diagnosis of malignant histiocytosis (MH), a disorder characterized by systemic proliferation of morphologically atypical histiocytes and their precursors, in an 8-year-old neutered female Golden Retriever was based on light and electron microscopic and immunohistochemical findings. Clinically, the dog presented with unilateral forelimb lameness. Eight days after surgical exploration of a swollen brachium, the dog developed sudden onset of posterior paresis, fecal and urinary incontinence, and a flaccid tail. Necropsy revealed infiltrative and nodular lesions in the right forelimb and regional lymph nodes, thoracic and abdominal cavities, and lumbar epidural space. Gross lesions were not found in the lungs or integument. Histopathologic examination showed infiltrates of atypical histiocytes in skeletal muscle, joint, and regional lymph nodes of the right forelimb; intercostal muscle; lung; liver; spleen; pancreas; kidneys; and spinal dura. Most tumor infiltrates were nodular and composed of loosely aggregated cells that were 10-30 microns in diameter with abundant eosinophilic to foamy cytoplasm, had central or eccentric nuclei, and were periodic acid-Schiff negative. Many binucleated cells, multinucleated giant cells, and mitotic figures were seen. Tumor cells contained phagocytosed erythrocytes, mononuclear cells, and some leukocytes. Ultrastructural features of tumor cells included cytoplasmic lipid droplets, lysosomes, and phagolysosomes. Immunohistochemical studies on paraffin-embedded sections showed positive reactivity to human T-cell Ag (clone UCHL-1) and for lysozyme, alpha-1-antitrypsin, and cathespin B. Polyclonal intracellular immunoglobulin reactivity and lectin binding (peanut, soybean, and wheat germ agglutinins and concanavalin A) were also demonstrated. Criteria for diagnosis of malignant histiocytic tumors and differential diagnosis are discussed.     

Effects of irradiation on the expression of major histocompatibility complex class I antigen and adhesion costimulation molecules ICAM-1 in human cervical cancer

PURPOSE: We initiated studies to analyze the effects of high doses of gamma irradiation on the surface antigen expression of MHC Class I, Class II, and ICAM-1 on human cervical carcinoma cell lines. METHODS AND MATERIALS: The expression of surface antigens (MHC Class I, Class II, and ICAM-1) was evaluated by FACS analysis on two cervical cell lines at different time points, following their exposure to high doses of gamma irradiation (i.e., 25.00, 50.00, and 100.00 Gy). RESULTS: The CaSki and SiHa cervical cancer cells we analyzed in this study expressed variable levels of MHC Class I and ICAM-1 antigens, while Class II surface antigens were not detectable. Whereas irradiation doses of 25.00 Gy were not sufficient to totally block cell replication in both cell lines, exposure to 50.00 or 100.00 Gy was able to completely inhibit cell replication. Range doses from 25.00 to 100.00 Gy significantly and consistently increased the expression of all surface antigens present on the cells prior to irradiation but were unable to induce neoexpression of antigens previously not expressed by these cells (i.e., MHC Class II). Importantly, such upregulation was shown to be dose dependent, with higher radiation doses associated with increased antigen expression. Moreover, when the kinetic of this upregulation was studied after 2 and 6 days after irradiation, it was shown to be persistent and lasted until all the cells died. CONCLUSIONS: These findings may partially explain the increased immunogenicity of tumor cells following irradiation and may suggest enhanced immune recognition in tumor tissue in patients receiving radiation therapy.     

Comparison of surgically attached and non-attached repair of the rat Achilles tendon-bone interface. Cellular organization and type X collagen expression

The effects of surgical repair versus non-repair on cell morphology and type X collagen expression were investigated using a rat model of Achilles tendon avulsion. The animals were divided into four groups. In Group 1, tendon was reattached to the original attachment site by suturing through a drill hole in the calcaneus; in Group II, tendon was not reattached and a drill hole was not made; in Group III, tendon was not reattached but a drill hole was made; and the animals in Group IV were sham operated. In Group I (tendon reattached), at 2 weeks postoperatively, many hypertrophic chondrocytes appeared at the reattachment site adjacent to bone and type X collagen was detected immunologically both in the cells and in the extracellular matrix. After 4 weeks, the cells at the original site of attachment were arranged in rows along the newly formed tendon fibers and were stained with type X collagen antibody. By contrast, when tendon was not reattached (Groups II and III), a gap between the original attachment site and the tendon stump was observed through the entire postoperative period. At 8 weeks, the original attachment site was covered by fibrocartilaginous tissue and tendon became attached to the calcaneal fibrocartilage area, which is proximal to the original attachment site. Type X collagen was detected in the cells which were adjacent to bone. In Group IV (sham operation), there were no changes in histology or type X collagen distribution, either at the attachment site or in tendon and bone, compared with the non-operated control rats. These results suggest that surgical reattachment of tendon to the original site is important to help reorganize cells during the repair process. Type X collagen was identified immunohistochemically in the cells adjacent to bone in all the groups, suggesting that it may play a role in maintaining distinct areas of calcified and non-calcified fibrocartilage.     

Assessment of digital EEG, quantitative EEG, and EEG brain mapping: report of the American Academy of Neurology and the American Clinical Neurophysiology Society

A. Digital EEG is an established substitute for recording, reviewing, and storing a paper EEG record. It is a clear technical advance over previous paper methods. It is highly recommended. (Class III evidence, Type C recommendation). B. EEG brain mapping and other advanced QEEG techniques should be used only by physicians highly skilled in clinical EEG, and only as an adjunct to and in conjunction with traditional EEG interpretation. These tests may be clinically useful only for patients who have been well selected on the basis of their clinical presentation. C. Certain quantitative EEG techniques are considered established as an addition to digital EEG in: C.1. Epilepsy: For screening for possible epileptic spikes or seizures in long-term EEG monitoring or ambulatory recording to facilitate subsequent expert visual EEG interpretation. (Class I and II evidence, Type A recommendation as a practice guideline). C.2. OR and ICU monitoring: For continuous EEG monitoring by frequency-trending to detect early, acute intracranial complications in the OR or ICU, and for screening for possible epileptic seizures in high-risk ICU patients. (Class II evidence, Type B recommendation as a practice option). D. Certain quantitative EEG techniques are considered possibly useful practice options as an addition to digital EEG in: D.1. Epilepsy: For topographic voltage and dipole analysis in presurgical evaluations. (Class II evidence, Type B recommendation). D.2. Cerebrovascular Disease: Based on Class II and III evidence, QEEG in expert hands may possibly be useful in evaluating certain patients with symptoms of cerebrovascular disease whose neuroimaging and routine EEG studies are not conclusive. (Type B recommendation). D.3. Dementia: Routine EEG has long been an established test used in evaluations of dementia and encephalopathy when the diagnosis remains unresolved after initial clinical evaluation. In occasional clinical evaluations, QEEG frequency analysis may be a useful adjunct to interpretation of the routine EEG when used in expert hands. (Class II and III evidence as a possibly useful test, Type B recommendation). E. On the basis of current clinical literature, opinions of most experts, and proposed rationales for their use, QEEG remains investigational for clinical use in postconcussion syndrome, mild or moderate head injury, learning disability, attention disorders, schizophrenia, depression, alcoholism, and drug abuse. (Class II and III evidence, Type D recommendation). F. On the basis of clinical and scientific evidence, opinions of most experts, and the technical and methodologic shortcomings, QEEG is not recommended for use in civil or criminal judicial proceedings. (Strong Class III evidence, Type E recommendation). G. Because of the very substantial risk of erroneous interpretations, it is unacceptable for any EEG brain mapping or other QEEG techniques to be used clinically by those who are not physicians highly skilled in clinical EEG interpretation. (Strong Class III evidence, Type E recommendation).     

Giant cell tumor of tendon sheath

The giant cell tumor of tendon sheath is a benign histiocytic proliferation of the articular and peritendinous synovial tissue that has only rarely been reported in the dermatologic literature. The lesion manifests as a firm 1 to 3 cm nodule most frequently occurring on the fingers, hands, and wrists, where it is attached to the tendon sheath. Its histopathologic appearance is characterized by the presence of multinucleate giant cells. The author reports a classic example of the giant cell tumor of tendon sheath.     

Atypical squamous cell carcinoma of the larynx and hypopharynx: radiologic features and pathologic correlation

The objective of this study was to analyze the radiologic features of atypical forms of squamous cell cancer and correlate them with clinical, endoscopic, and histopathologic findings. The CT and MRI images of 31 patients with atypical forms of squamous cell carcinoma were reviewed retrospectively and the radiologic findings were correlated with clinical, endoscopic, and histopathologic findings. Histopathologic diagnoses included undifferentiated carcinoma of nasopharyngeal type (n = 8), verrucous carcinoma (n = 18), spindle cell carcinoma (n = 3), and basaloid cell carcinoma (n = 2). Undifferentiated carcinoma of nasopharyngeal type was located in the supraglottis or piriform sinus beneath an intact mucosa and initial endoscopic biopsy was most often negative. The discrepancy between an intact mucosa at endoscopy and a solid mass with homogenous enhancement at CT or MRI was characteristic for these tumors and warranted further investigations to obtain the definitive histologic diagnosis. Verrucous carcinoma displayed characteristic clinical, radiologic, and pathologic features, namely, an exophytic tumor arising from the glottic level displaying a rugged surface with finger-like projections but with only minor submucosal infiltration. Spindle cell carcinoma appeared as a polypoid mass with a thin stalk arising from the supraglottis. Basaloid cell carcinoma displayed a distinct lobulated enhancement pattern which was observed on contrast-enhanced T1-weighted SE images. Although the MR and CT features of atypical forms of squamous cell carcinoma cannot be considered pathognomonic they should raise the differential diagnosis even if endoscopic biopsy has been negative. The radiologist's awareness of the appearance of these unusual tumors on CT and MR images may greatly facilitate the diagnostic work-up and helps to guide the endoscopist to the adequate biopsy site in order to establish the correct diagnosis.     

Malignant histiocytosis. Histologic, cytochemical, chromosomal, and molecular data with a nosologic discussion

Although myelomonoblastic leukemia is thought to originate from a malignant transformation of the stem cell of the mononuclear phagocyte system, malignant histiocytosis (MH) is classically assumed to represent a malignant change of the terminal and fixed elements of this system. Indeed, MH is characterized by the proliferation of large, clear, pleomorphic, "histiocytic-like" HLADR and CD30+ cells resulting in a nodal and extranodal disseminated neoplasm affecting preferentially and severely children and young adults. Although there is broad agreement on the clinicopathologic presentation of this condition, there is currently quite a controversy over the T-lymphoid or histiocytic origin of the proliferative cells that results in a nosologic discussion between the anaplastic large cell lymphoma (ALCL) advocates and the MH supporters. This article has dealt mainly with this nosologic discussion and with the contributions provided by the investigations performed on MH permanent cell lines. These in vitro studies have demonstrated that the proliferation is characterized by a unique chromosomal abnormality, the 5q35bp usually associated with a t(2;5) translocation generating a fusion gene NPM/ALK and the subsequent translation of p80 protein. Although it is known that no single chromosomal abnormality is strictly restricted to a cell lineage, this 5q35bp and associated translocations seem today to represent the hallmark for this condition. In view of these chromosomal aberrations, the CD30+ ALCLs represent a heterogeneous group because 15% to 50% express the NPM/ALK fusion gene. In addition, these in vitro investigations have shown that 5q35bp proliferative cells are glass-adherent, can develop an immunodependent phagocytosis, and are able to reduce NBT and produce TNF-alpha. More significantly, they express constitutively the c-fms (the receptor of the macrophage growth factor) and, under TPA stimulation, are able to modulate the expression of this receptor and its ligand, as well as TNF-alpha and IL-1. None of these cell lines express CD3, but several express CD68 and CD71. In contrast, genomic investigations have shown the underlying existence of monoallelic and even biallelic gene rearrangements for TCR beta and IgJH. In view of these discrepancies between the genomic and phenotypic features of these cells, the histogenetic debate should remain open but must take into account these new chromosomal and molecular data.     

Untreated cervical infections, chorioamnionitis and prematurity

Myotonic dystrophy (DM) is a disease involving multiple organs. To elucidate the extent of severity of the affected organs in a given individual, we performed an investigation of the Ellsworth-Howard test (EH test), intelligence quotient (IQ), apnea index (AI), and expanded DNA fragment (EF) size in 10 patients with DM. The EF size analyzed by standard Southern blot procedures using EcoRI digested genomic DNA extracted from the peripheral white blood cells and probed with cDNA25. In the EH test, these patients were divided into two groups according to the results of their phosphaturic responses (delta P). Of these, 5 patients (Group I) showed a positive delta P, while remaining 5 patients (Group II) showed a negative one. In both Groups I and II, their urinary cyclic AMP responses were positive. Group II showed a significantly low value in IQ (p < 0.02) and a significantly high value in AI (p < 0.02) as compared with Group I. EF size in Group II was found significantly larger than in Group I (p < 0.01). A positive correlation between delta P and IQ (p < 0.1), a significant negative one between delta P and AI (p < 0.01), and a negative correlation between EF size and delta P (p < 0.2) were observed. IQ was negatively (p < 0.05), and AI was positively (p < 0.05) correlated with EF size, which were statistically significant. Our results suggest that the extent of disease severity of the central nervous system is almost the same as that of endocrine organs, and that EF size is correlated with disease severities in both affected organs.(ABSTRACT TRUNCATED AT 250 WORDS)     

CNS sequelae in Langerhans cell histiocytosis: progressive spinocerebellar degeneration as a late manifestation of the disease

Central nervous system involvement in Langerhans cell histiocytosis (LCH), formerly known as histiocytosis X, is manifested mainly by diabetes insipidus reflecting local infiltration of Langerhans cells into the posterior pituitary or hypothalamus. We describe two patients with progressive spinocerebellar degeneration appearing 4 and 6 years after the initial diagnosis of LCH. No correlation was found between the clinical course of the disease or its treatment and the neurological impairment. An extensive search for metabolic, toxic, neoplastic, and hereditary etiologies for progressive cerebellar degeneration was negative.     

True histiocytic lymphoma: a morphologic, immunohistochemical, and molecular genetic study of 13 cases

We describe the morphologic, immunohistologic, and genotypic characteristics of 13 cases of true histiocytic lymphomas. Six cases presented with primary gastrointestinal involvement, five with lymphadenopathy, the other sites involved being the bone marrow and the skin. The neoplastic cells displayed large abundant eosinophilic cytoplasm, occasionally vacuolated with folded or bizarre-shaped nuclei with prominent nucleoli. Mitotic figures were numerous. Multinucleated cells were common. The pattern of growth was usually diffuse and noncohesive. Spindle cell sarcoma-like areas were evident in five cases, with a prominent foam cell component in four cases. All cases expressed histiocyte-associated markers (CD68, lysozyme, alpha-1-antitrypsin), CD45 or CD45RO, and were negative for CD1a, epithelial, and B- and T-cell lineage-specific markers. Reactivity for S-100 was observed in a variable proportion of cells in 11 cases. The proliferation fraction varied from 3 to 88%. Genotypic analysis for T-cell receptor or immunoglobulin gene rearrangement demonstrated a germline configuration in all cases. We demonstrate that true histiocytic lymphoma is a rare distinctive pathologic entity that may be defined by immunohistochemical criteria and that recognition among histiocytic disorders is important for clinical and prognosis reasons.     

Clinical analysis of inflammatory masses of the pancreatic head region

BACKGROUND/AIMS: Inflammatory masses of the pancreatic head are a dilemma for surgeons, especially when the differences between these lesions and pancreatic head carcinoma are not so clear. The surgical management of these inflammatory benign lesions is also a topic with conflicting opinions. A clinical analysis was performed in an attempt to differentiate between these lesions and malignancy. The results of our observatory strategy of these lesions are also presented. METHODOLOGY: From 1992 to 1994, 73 patients with ultrasonographically (US) or computed tomographically (CT) heterogenous pancreatic head lesions were diagnosed at the Department of Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan. Forty-nine of these lesions were neoplastic (Group I), but the remaining 24 patients had inflammatory non-neoplastic lesions (pancreatic inflammatory masses, IPM, Group II), which were diagnosed during laparotomy by core needle biopsy. Surgery and outcome were reviewed. Ten of the 24 patients in group II received biopsy only, and the remaining 14 patients received bypass procedures. At follow-up of at least 16 months of the surviving patients (n=21), only 9.5% were with residual lesions. All cases in group II revealed shrinkage of masses. We focused on the clinical features, hematology, biochemistry, image study, serum CEA and CA 19-9, and compared these variances between the 2 groups. RESULTS: Three clinical features were statistically different between groups I and II: mean age at presentation of disease (group I vs II = 53.3 vs 65.1), the tendency of a past history of alcoholism (Group II), and presence of abdominal pain (Group II). Group II also showed a higher level of serum alkaline phosphatase and a lower level of total bilirubin as well as a lower level of CA19-9. These inflammatory masses could not be distinguished from the true neoplasms pre-operatively on endoscopic appearance, US, or CT. CONCLUSIONS: Pre-operative differentiation between these pancreatic lesions may be difficult but laparotomy and core needle biopsy remain safe and reliable procedures. Our short-term follow-up justified the bypass surgery and that observatory strategy is enough for those patients with pancreatic head inflammatory masses.