Small Cell Variant Research Articles

Immunogistokhimicheskaya kharakteristika i kriterii prognoza sarkomy Yuinga/PNET

A group of high-grade small round-cell neuroectodermal tumors developing in soft tissues and bones has been recently identified in children and young adults on the basis of the data of classical morphology and the results obtained by new techniques (cell culturing, molecular genetics, immunohistochemistry). To denote these tumors, the term "primitive peripheral neuroectodermal tumor" (PNET) has been proposed. The problem is of great practical importance in the differential diagnosis of formally similar malignancies (lymphoma, embryonal rhabdomyosarcoma, synovial sarcoma, small-cell variant of osteosarcoma), this makes PNET and Ewing's sarcoma be histogenetically and clinicodiagnostically of special scientific and practical interest.

Scrotal pearls

The present paper reports for the first time the discovery of a rickettsia-like organism (RLO) in the cultured tropical marine pearl oysterPinctada maximawith mass mortality in the Hainan Province of China. This organism parasitizes the cytoplasm of host cells and forms intracytoplasmic eosinophilic inclusions. These organisms are extremely pleiomorphic in shape and average 967 × 551 nm in size, as measured in cross sections of transmission electron micrographs. The organisms exhibit clearly recognizable ultrastructural characteristics of prokaryotic bacteria-like cells, including two trilaminar membranes, an increasing electron-dense periplasmic ribosome zone, and a thread-like DNA nucleoidal structure. In addition to the above prokaryotic characteristics, the following unique biological characteristics were confirmed by TEM: (i) These organisms are usually located in host cells in two ways, namely, free in the cell cytoplasm and involved within membrane-limited phagolysosomes; (ii) The organisms exist in two morphological cell types, namely a small cell variant (SCV) and a large cell variant (LCV). The most important morphological difference between two cell types is that the SCV is obviously ribosome-rich in the periphery of the body, which makes SCV more electron-dense in the cytoplasm and narrower in the central nucleoid area than the LCV; (iii) Two propagative modes of the organisms, transverse binary fission and budding, are observed in cytoplasm and phagolysosomes of host cells under TEM, in which the budding is more often seen in phagolysosomes. These characteristics indicate that the organism is a separate species in the family Rickettsiaceae and should be classified into the genusRickettsia.On the basis of the existence of the two propagative modes and two cell types, and intracellular location, we propose a developmental cycle for this organism which includes a vegetative differentiation stage to develop LCV by transverse binary fisson and a budding differentiation stage to develop resistant SCV.

Malignant Peripheral Nerve Sheath Tumour of the Breast in Complex Clinical Background

Malignant Peripheral Nerve Sheath Tumour of the Breast in Complex Clinical Background Here we describe a patient presenting with combination of three rare diseases, namely de novo malignant peripheral nerve sheath tumour of the breast, small cell variant of medullary thyroid carcinoma and multiple sclerosis. Although the combination by chance seems unlikely, the detailed history does not correspond to any of the known hereditary cancer syndromes and hypothetically may represent a new entity.

Immunophenotyping of mature T/NK cell neoplasm presenting as leukemia

Mature T/NK cell lymphomas (MTNKL) presenting as leukemia are rare and show considerable overlapping of clinical, morphological and immunophenotypic features. Critical analysis of the morphology and immunophenotypic profile of MTNKL. We reviewed 380 consecutive cases of mature lymphoid neoplasm that presented as leukemia and were diagnosed on morphology and immunophenotyping of bone marrow and/or peripheral blood samples. Peripheral blood and bone marrow involvement was seen in all cases. MTNKL constituted 4% (nine cases) of all mature lymphoid neoplasms presenting as leukemia. It included four cases of T-large granular leukemia (T-LGL), two of T-cell prolymphocytic leukemia small cell variant (T-PLL), two of adult T-cell leukemia/lymphoma (ATLL) and one of primary cutaneous gamma delta T-cell lymphoma (PCGDTCL). T-LGL revealed CD4-/CD8+ phenotype in three, and CD4+/CD8+ phenotype in one case. CD56 was absent in all the cases of T-LGL. One case of T- PLL small cell variant showed CD4+/CD8- phenotype, while the other revealed CD4-/CD8+ phenotype. Both cases of ATLL showed CD4+/CD8+/CD25+ phenotype. The single case of PCGDTCL showed CD4-/CD8- phenotype pattern. CD3 and CD5 were expressed in all MTNKL. CD7 was absent in three cases of T-LGL. TCRalpha/beta was performed in three cases of T-LGL and was positive in all. TCRalpha/beta was also seen in both the cases of T-PLL small variant. However, TCRalpha/beta was seen in the single case of PCGDTCL. Mature nodal T/NK cell neoplasms are rare and MTNKL presenting as leukemia are even rarer. There is an overlap between the immunophenotypic profiles of different MTNKL subtypes and elaborate T/NK cell panels are required for their evaluation.

Small cell variant of anaplastic large cell lymphoma: a 10‐year review of the All Wales Lymphoma Panel database

Small cell variant of anaplastic large cell lymphoma: a 10‐year review of the All Wales Lymphoma Panel database

Small cell variant of peripheral T-cell lymphoma, not otherwise specified: a clinicopathologic and immunophenotypic analysis

To study the clinicopathologic features and differential diagnosis of small cell variant of peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS). The clinicopathologic features of 5 cases of small cell variant of PTCL, NOS were retrospectively reviewed, with immunohistochemical study, T-cell receptor (TCR) gene rearrangement analysis and evaluation for Epstein-Barr virus (EBV) status. All the 5 patients were males. The mean age was 52.6 years. The median duration before diagnosis was 1 month. Clinically, 3 patients presented in stage IV and 2 in stage III. Four of them had generalized lymphadenopathy and splenomegaly. Hepatomegaly and massive effusion were found in 1 and 2 cases, respectively. Marrow involvement was detected in 3 of the 4 patients with bone marrow biopsy performed and one of them also accompanied by lymphocytosis. Histologically, the involved lymph nodes showed partial or complete effacement of nodal architecture and replacement by a monomorphous population of small lymphoid cells. Scanty large lymphoid cells were also identified in 4 cases. Increase in number of blood vessels was noticed in two of them as well. Immunohistochemically, the lymphoma cells in all cases expressed two or more of the T-cell markers and CD43. The staining for CD20, TdT, CD56 and granzyme B was negative. CD99 expression was noted in 3 of the 4 cases. The Ki-67 index ranged from 5% to 15%. Clonal TCRgamma gene rearrangement was detected in the 4 cases studied and one of them also showed TCRbeta gene rearrangement. In-situ hybridization for EBV-encoded RNA was negative in the 4 cases studied. Follow up information was available in 3 of the 5 cases. All of the 3 patients died of the disease, with an average survival of 21.7 months. Small cell variant of PTCL, NOS represents a rare disease entity which often presents in advanced tumor stage and carries a poor prognosis.

Anaplastic large cell lymphoma in leukemic phase: Extraordinarily high white blood cell count

Anaplastic large cell lymphoma (ALCL) is a distinct type of T/null-cell non-Hodgkin lymphoma that commonly involves nodal and extranodal sites. The World Health Organization of lymphoid neoplasms recognizes two types: anaplastic lymphoma kinase (ALK) positive or ALK negative, the former as a result of abnormalities involving the ALK gene at chromosome 2p23. Patients with ALCL rarely develop a leukemic phase of disease, either at the time of initial presentation or during the clinical course. Described herein is a patient with ALK+ ALCL, small cell variant, associated with the t(2;5)(p23;q35), who initially presented with leukemic involvement and an extraordinarily high leukocyte count of 529 x 10(9)/L, which subsequently peaked at 587 x 10(9)/L. Despite chemotherapy the patient died 2(1/2) months after diagnosis. In the literature review 20 well-documented cases are identified of ALCL in leukemic phase reported previously, with a WBC ranging from 15 to 151 x 10(9)/L. Leukemic phase of ALCL occurs almost exclusively in patients with ALK+ ALCL, most often associated with the small cell variant and the t(2;5)(p23;q35), similar to the present case. Patients with leukemic phase ALK+ ALCL appear to have a poorer prognosis than most patients with ALK+ ALCL.

Frequent Expression of CD99 in Anaplastic Large Cell Lymphoma

Originally described as a diagnostically useful marker for Ewing sarcoma, CD99 immunoreactivity has also been documented in a variety of other tumors, including hematopoietic neoplasms. By using conventional paraffin immunoperoxidase staining and tissue microarrays, we retrospectively investigated CD99 expression in a series of 160 anaplastic large cell lymphoma (ALCL) cases. Of the 160 cases, 103 (64.4%) were positive for CD99. The distribution of CD99 positivity was similar for nodal (66/103 [64.1%]), extranodal, (21/32 [66%]), and primary cutaneous lesions (16/25 [64%]). CD99 expression was present in 96 (64.4%) of 149 of the common type, 4 (80%) of 5 of the small cell variant, and 3 (50%) of 6 of the lymphohistiocytic variant cases. CD99 expression was slightly more frequent in anaplastic large cell lymphoma kinase (ALK)+ cases compared with ALK- cases (43/54 [80%] vs 44/81 [54%]). With 2 exceptions, ALK+ ALCL was seen only in patients younger than 41 years. We conclude that CD99 is frequently expressed in ALCL, with a slightly increased frequency in the younger age ALK+ cases. Nodal and extranodal ALCL should be considered in the differential diagnosis when a CD99+ neoplasm is encountered.

Immunogistokhimicheskaya kharakteristika i kriterii prognoza sarkomy Yuinga/PNET

A group of high-grade small round-cell neuroectodermal tumors developing in soft tissues and bones has been recently identified in children and young adults on the basis of the data of classical morphology and the results obtained by new techniques (cell culturing, molecular genetics, immunohistochemistry). To denote these tumors, the term "primitive peripheral neuroectodermal tumor" (PNET) has been proposed. The problem is of great practical importance in the differential diagnosis of formally similar malignancies (lymphoma, embryonal rhabdomyosarcoma, synovial sarcoma, small-cell variant of osteosarcoma), this makes PNET and Ewing's sarcoma be histogenetically and clinicodiagnostically of special scientific and practical interest.

Generalized Leukaemia Cutis from a Small Cell Variant of T-cell Prolymphocytic Leukaemia Presenting with Exfoliative Dermatitis

T-cell prolymphocytic leukaemia (T-PLL) is a rare, aggressive neoplasm of mature T lymphocytes. The small cell variant occurs in approximately 20% of T-PLL patients. The skin findings of leukaemia consist of leukaemia-specific skin lesions, which are infiltrated by leukaemia cells, and non-specific lesions. The former type of lesion signifies leukaemia cutis. Leukaemia cutis presents clinically as tumours, nodules, or patches on the scalp, face and trunk. We report here an 82-year-old Korean male patient who presented with erythema, erosion, vesicles, and scales on his entire body with no clear underlying cause. He had been treated with oral retinoids, steroids, and phototherapy for the diagnoses of drug eruption, pityriasis rubra pilaris, and exfoliative dermatitis at other hospitals. We suspected a hidden malignancy and diagnosed small cell variant T-PLL through blood and bone marrow examination. A skin biopsy specimen showed dense infiltration of small lymphocytes in the dermis. Most of the atypical lymphocytes stained positively with CD markers such as CD2, CD3, CD4, CD5, CD7 and CD8, thereby confirming the presence of leukaemia cells. To our knowledge, this is the first case of generalized leukaemia cutis from small cell variant of T-PLL presenting with exfoliative dermatitis over the whole body.

C-Terminal Defect of CD20 on T-Cell Leukemia/Lymphoma Cells: Implications for Resistance to Rituximab

Rituximab is commonly used for treatment of B-cell leukemia/lymphoma and its efficiency on CD20+ B-cell malignancies has been established. On the other hand, the effect of rituximab on CD20+ T cell leukemia/lymphoma is unclear. Two patients CD20+ T-cell malignancy (1 with T-cell prolymphocytic leukemia (T-PLL) and 1 with peripheral T-cell lymphoma, unspecified (PTCL-u)) were recently treated with rituximab without appreciable effects. The treatment failure prompted a study of the mechanisms underlying the resistance to rituximab therapy using leukemia/lymphoma cells of these patients and another CD20+ T-PLL patient. Patient 1: A 68-year old Japanese male was diagnosed as having T-PLL (small cell variant) characterized by CD2+CD3+CD4− CD5+CD8+CD20+TCR-Vβ8+. Southern blotting of these T-PLL cells showed a TCR-β gene rearrangement. The systemic lymphadenopathy and high-fever of the patient were ameliorated by the administration of prednisolone (20 mg/d). Rituximab was administered weekly, but no clinical improvement was observed. In vitro treatment of the T-PLL cells with rituximab did not show any complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC). Patient 2: A 75-year old Japanese male was diagnosed as having T-PLL (small cell variant) with a phenotype of CD2+CD3+CD4+CD5+CD8+CD20+. Southern blotting of these T-PLL cells showed a TCR-β gene rearrangement. The patient is being followed without treatment because his pancytopenia is non-progressive. Patient 3: A 67-year old Japanese male developed a left thigh tumor which proved to be PTCL-u. The phenotype of lymphoma cells was CD2+CD3−CD4−CD5−CD8+CD20+ and Southern blotting of these cells showed a TCR-β gene rearrangement. The patient's PTCL-u was refractory to CHOP and rituximab plus EPOCH therapy. The reactivity of various monoclonal Abs specific to CD20 molecules against these patients' leukemia/lymphoma cells is summarized in Table 1. CD20 molecules of these 3 patients' leukemia/lymphoma cells were detectable by flow cytometry using anti-CD20 mAbs (L27 and rituximab) and also by Western blotting using anti-CD20 mAbs which recognize N-terminal region of CD20. However, the CD20 molecules could not be revealed either by immunohistochemistry using anti-CD20 mAbs (L26) or by Western blotting using anti-CD20 mAbs which recognize C-terminal region of CD20. The sequence of the full-length CD20 cDNA derived from Patient 1's T-PLL cells proved to be intact. These results indicate that the CD20 molecules of the 3 patients' leukemia/lymphoma cells have defects in the cytoplasmic C-terminal region which may impair the cytotoxic effect of rituximab such as CDC and ADCC and the defect may be due to post translational changes such as phosphorylation of serine and threonine residues.Table 1. Reactivity to different Abs specific to CD20PtAgeGenderL27 (FACS)Rituximab (FACS)L26 (IHC)C-terminal Ab (WB)N-terminal Ab (WB)168M++−−+275M++−−+367M+ND−−+FACS, flow cytometry; IHC, immunohistochemistry; WB, Western blotting; +, positive; −, negative; ND, not determined

Small cell variant of anaplastic large cell lymphoma diagnosed by a novel chromosomal abnormality t(2;5;3)(p23;q35;p21) of bone marrow cells

Because of the rarity and the morphological variations, small cell variant of anaplastic large cell lymphoma (ALCL) represents a diagnostic challenge. Herein is reported a case of leukemic type of small cell variant of ALCL, in which the diagnosis was established by a cytogenetic analysis. The patient was a 23-year-old woman who presented with fever and leukocytosis with circulatory atypical lymphoid cells. The initial differential diagnosis on bone marrow trephine biopsy sections included viral infection and peripheral T-cell lymphoma unspecified. But a cytogenetic study on bone marrow cells indicated a novel complex translocation, t(2;5;3)(p23;q35;p21), which led to confirmation of anaplastic lymphoma kinase (ALK)-positive pleomorphic small to medium-sized cells scattered in bone marrow cells, on immunohistochemistry. ALK was distributed in both nuclear and cytoplasmic regions of neoplastic cells. The patient achieved complete remission after four courses of combination chemotherapy, and received autologous peripheral stem cell transplantation (auto-PBSCT) after two additional courses of combination chemotherapy, but relapsed 2 months after auto-PBSCT in the bilateral lung. Allogeneic stem cell transplantation led to a second remission. This case demonstrates the diagnostic importance of cytogenetic study for malignant lymphoma involving bone marrow.

Sustained Axenic Metabolic Activity by the Obligate Intracellular Bacterium Coxiella burnetii

Growth of Coxiella burnetii, the agent of Q fever, is strictly limited to colonization of a viable eukaryotic host cell. Following infection, the pathogen replicates exclusively in an acidified (pH 4.5 to 5) phagolysosome-like parasitophorous vacuole. Axenic (host cell free) buffers have been described that activate C. burnetii metabolism in vitro, but metabolism is short-lived, with bacterial protein synthesis halting after a few hours. Here, we describe a complex axenic medium that supports sustained (>24 h) C. burnetii metabolic activity. As an initial step in medium development, several biological buffers (pH 4.5) were screened for C. burnetii metabolic permissiveness. Based on [(35)S]Cys-Met incorporation, C. burnetii displayed optimal metabolic activity in citrate buffer. To compensate for C. burnetii auxotrophies and other potential metabolic deficiencies, we developed a citrate buffer-based medium termed complex Coxiella medium (CCM) that contains a mixture of three complex nutrient sources (neopeptone, fetal bovine serum, and RPMI cell culture medium). Optimal C. burnetii metabolism occurred in CCM with a high chloride concentration (140 mM) while the concentrations of sodium and potassium had little effect on metabolism. CCM supported prolonged de novo protein and ATP synthesis by C. burnetii (>24 h). Moreover, C. burnetii morphological differentiation was induced in CCM as determined by the transition from small-cell variant to large-cell variant. The sustained in vitro metabolic activity of C. burnetii in CCM provides an important tool to investigate the physiology of this organism including developmental transitions and responses to antimicrobial factors associated with the host cell.

Cytologic Features of Ascitic Fluid Complicated by Small Cell Variant T-cell Prolymphocytic Leukemia -A Case Report-

T-cell prolymphocytic leukemia (T-PLL) is a rare, mature T-cell lymphoproliferative disorder with a post-thymic mature T-cell phenotype. The disease is characterized by rapidly rising lymphocytosis, lym-phadenopathy, and splenomegaly. The clinical course is usually aggressive and progresses with frequent skin lesions and serous effusions. In 25% of cases, leukemic cells are small and tumor cells may not have a discrete nucleolus under light microscopy. Although the presence of characteristic cytoplasmic protrusions or blebs in tumor cells is a common morphologic finding in the peripheral blood film irrespective of the nuclear features, small cell variants lacking the typical nuclear features can cause diagnostic problems in clinical cytology. Furthermore, the small leukemic cells can share some cytologic findings with lymphocyte-rich serous effusions caused by non-neoplastic reactive lymphocytosis as well as other small lymphocytic lymphoproliferative disorders. Here, we describe the cytological findings of ascitic fluid complicated by small cell variant T-PLL in a 54-year-old man, the cytology of which was initially interpreted as small lymphocytic malignancy such as small lymphocytic lymphoma/chronic lymphocytic leukemia.

Merkel Cell Carcinoma and Azzopardi Phenomenon

To the Editor: Foci of strongly hematoxyphilic blood vessels appearing as the result of chromatin diffusion secondary to necrosis of neoplastic tissue are sometimes referred to as the Azzopardi phenomenon.1 This phenomenon was named after John G. Azzopardi, who had identified the basophilic granular material in the vessel wall as DNA, having examined cases of small cell carcinoma of the lung.2 Merkel cell carcinoma (MCC) is an aggressive primary neuroendocrine tumor of the skin that was described by Toker3 in 1972. The most important differential diagnosis of MCC is metastatic small cell carcinoma of the lung; it often requires combined assessment of the clinical features, light microscopy, and immunohistochemistry.4-6 A paper by Schmidt and coworkers7 that appeared in this journal in 1998 documented the presence of the Azzopardi phenomenon in MCC. Yet, most recently, Patterson and Wick,8 the authors of the new AFIP Atlas of Nonmelanocytic Tumors of the Skin, have stated that the Azzopardi phenomenon is never seen in primary neuroendocrine tumors of the skin, in particular MCC, suggesting that this histopathological feature may be used as a clue to metastatic small cell carcinoma of the lung. Besides the paper of Schmidt et al,7 the only other two articles mentioning the Azzopardi phenomenon in MCC that we were able to find in the literature are the paper by Sibley et al9 and the paper by Foschini and Eusebi.10 This controversy prompted us to review our cases of MCC to check whether the Azzopardi phenomenon is present in this cutaneous neoplasm. Among 83 cases of MCC retrieved from our files, the Azzopardi phenomenon was found in three tumors (Fig. 1). This frequency is somewhat lower than was seen in the series of Schmidt and colleagues, who identified DNA deposits in vessel walls in 7 of 76 studied cases of MCC. Interestingly, all seven of these cases were found among the so-called small cell variant. Although the morphological subdivision of MCC into intermediate, small cell, and trabecular subtypes is used, in our experience, this subclassification is arbitrary: a majority of our cases exhibited a combination of these three morphological patterns. Likewise, all three cases in which we detected the Azzopardi phenomenon manifested small cell areas, intermediate cell morphology, and trabecular arrangement of the neoplastic cells. It seems to us that the Azzopardi phenomenon is indeed a rare feature in MCC, but, taken alone, it cannot be used as a diagnostic criterion for distinguishing MCC from metastatic small cell carcinoma of the lung.FIGURE 1: The Azzopardi phenomenon in Merkel cell carcinoma of the skin: several vessels with dense DNA depositions in their walls.Marina Vazmitel, MD Academy of Postgraduate Education of Belarus Minsk, Republic of Belarus Michal Michal, MD Dmitry V. Kazakov, MD, PhD Sikl's Department of Pathology Charles University, Medical Faculty Hospital Pilsen, Czech Republic

Anaplastic Large Cell Lymphomas: A Study of 75 Pediatric Patients

In this article, we describe the morphologic and immunophenotypic features of 75 cases of pediatric anaplastic large cell lymphoma (ALCL). According to the World Health Organization classification, 49 cases were common subtype ALCL, and respectively, 3, 6, and 17 cases were small cell, lymphohistiocytic, or mixed histologic variants. Anaplastic lymphoma kinase positivity was detected in 90.7% of the tumors and, using a panel of 9 T-cell surface markers, 88% could be assigned to the T-cell lineage. A molecular analysis for the T-cell receptor gamma (TCR- gamma) and the heavy chain of the immunoglobulin H rearrangements was performed on 6/9 ALCLs with a null immunophenotype, and a TCR clonal pattern was detected in 5/6 cases. In addition, 94.1% were immunoreactive for 1 or more cytotoxic proteins (Tia1, granzyme B, or perforin), and 15% expressed CD56. Clusterin, CD83, and Pax5, respectively, expressed in 91.3%, 1.7%, and 0% of the ALCLs, were useful biomarkers for the differential diagnosis with Hodgkin's lymphomas.

Error reduction and risk management in cytopathology

Currently, tort reform is not a major priority in either the Congress of the United States or in state legislatures. Thus, it is fortunate that medical negligence claims against pathologists are relatively infrequent, at 8.3% per year per 100 insured pathologists (data from the Doctors' Company, 2000-2003). However, claims for "missed" cervical cytology specimens rank third, behind those for alleged misinterpretation of breast biopsies and pigmented skin lesions. The severity of cervical cytology errors is high, at almost $700,000 per claim, surpassed only by those concerning melanoma. There are common threads that appear consistently in the analysis of slides from allegedly misdiagnosed cervical cytology cases, including small-cell variants of high-grade squamous intraepithelial neoplasia (HGSIL), present in small numbers; hyperchromatic crowded cell groups; atypical squamous cells of undetermined significance (ASCUS); smears taken during menses; other bloody smears, particularly with degenerative features or excessive inflammation; others showing atypical repair; and unsatisfactory samples. It is important for pathologists to spend time with cytotechnologists to emphasize the patterns of abnormal smears at low microscopic magnification and those backgrounds featuring blood and inflammation which require particular attention. Managing the "look-back" requirement of the Clinical Laboratory Amendments of 1988 (CLIA88) is also crucial; the need to issue amended reports as a consequence of that provision is quite rare. Procedures for administrating and reporting retrospective reviews under the CLIA88 should be clearly outlined in a peer-reviewed procedure document in each laboratory. They should be reviewed and approved by risk managers or insurance carriers, and documented in such a manner that one obtains maximal protection from legal discovery. Consumer education is particularly important in maintaining laboratory performance and reducing risk from error in cytology. Periodic feedback to clinicians on the quality of their smear preparations, the use of ancillary techniques (eg, human papillomavirus testing), and discussion of reporting terminology are important. Moreover, one should stress the need for pertinent clinical history that is often required to initiate quality control measures for evaluation and reporting of cervical cytology specimens. The incidence of cervical cancer in the United States, at only 9700 new cases per year, is low, emphasizing the need for clinical vigilance, attention to unexplained symptoms and signs, and biopsies of any cervical abnormality. These and other efforts may assist in reducing the risk of litigation attached to allegedly false-negative gynecologic and nongynecologic cytology samples.

Highly aggressive ALK-positive anaplastic large cell lymphoma with a leukemic phase and multi-organ involvement: a report of three cases and a review of the literature

Anaplastic large cell lymphoma (ALCL) is an aggressive neoplasm of T- or null cell phenotype and is recognized as a distinct clinicopathologic subtype of non-Hodgkin lymphoma (NHL) in the revised World Health Organization (WHO) classification of hematopoietic neoplasms. It is rarely associated with leukemic phase. Most cases with leukemic involvement are the small cell variant of ALCL. These cases often lack the pleomorphism seen in the common variant of ALCL and may be misdiagnosed. We report a series of three patients who presented with leukemic phase ALCL. The patients included an 11-year-old boy, a 29-year-old man, and a 59-year-old woman. The clinical and pathologic features of these cases are reviewed. The patients in our case series with leukemic phase ALCL exhibited rare clinical features. The patients presented with massive extranodal disease involving cerebrospinal fluid (CSF), liver, spleen, lungs, and bone marrow. CSF involvement was documented morphologically as well as by flow cytometry in two patients. Two of the patients had small cell variant and the third patient had common type ALCL. The neoplastic cells in all three patients were ALK positive; however these patients died within months of diagnosis. Leukemic phase ALCL is rare, and behaves in an aggressive manner. Some, but not all, cases in the literature presenting with peripheral blood involvement had small cell variant ALCL, as seen in two of our cases. The leukemic phase of ALCL should be considered when a T-cell leukemia with unusual morphologic features is encountered.

Proteome and Antigen Profiling of Coxiella burnetii Developmental Forms

A biphasic developmental cycle whereby highly resistant small-cell variants (SCVs) are generated from large-cell variants (LCVs) is considered fundamental to the virulence of Coxiella burnetii, the causative agent of human Q fever. In this study a proteome analysis of C. burnetii developmental forms was conducted to provide insight into their unique biological and immunological properties. Silver-stained gels of SCV and LCV lysates separated by two-dimensional (2-D) gel electrophoresis resolved over 675 proteins in both developmental forms. Forty-eight proteins were greater than twofold more abundant in LCVs than in SCVs, with six proteins greater than twofold more abundant in SCVs than in LCVs. Four and 15 upregulated proteins of SCVs and LCVs, respectively, were identified by mass spectrometry, and their predicted functional roles are consistent with a metabolically active LCV and a structurally resistant SCV. One-dimensional and 2-D immunoblots of cell form lysates probed with sera from infected/vaccinated guinea pigs and convalescent-phase serum from human patients who had recovered from acute Q fever, respectively, revealed both unique SCV/LCV antigens and common SCV/LCV antigens that were often differentially synthesized. Antigens recognized during human infection were identified by mass spectroscopy and included both previously described immunodominant proteins of C. burnetii and novel immunogenic proteins that may be important in the pathophysiology of clinical Q fever and/or the induction of protective immunity.

Small cell variant of CD30+ primary cutaneous T-cell lymphoma with epidermotropism that completely regressed after incisional skin biopsy

Conflicts of interest: none declared. Sir, CD30+ primary cutaneous T‐cell lymphomas (CTCLs) without anaplastic large lymphoid cytology are extremely rare, especially with epidermotropism.1 In the literature we found few reports of primary CTCL predominantly composed of CD30+ small‐ to medium‐sized lymphoma cells.1, 2 We report on two patients with small cell CD30+ primary CTCL without anaplastic large cell phenotype. CD30+ atypical lymphoid cells showed epidermotropism, i.e. these cells were present not only in the dermis but also in the epidermis singly and in clusters. These tumours regressed completely after incisional skin biopsy. These two cases indicate that even primary CTCLs without anaplastic large cell cytology should be immunohistochemically examined for the expression of CD30 because CD30+ lymphomas have a significantly favourable prognosis when they are confined to the skin. Patient 1. In July 2003, a 32‐year‐old woman presented with an asymptomatic erythematous nodule on her right cheek (Fig. 1a). It had progressively enlarged over 1·5 months. The diameter of the nodule was 1·5 cm at presentation. No other similar lesions were noticed on other areas of the skin, and lymph nodes were not palpable.