Duodenal-type follicular lymphoma: comprehensive insights into disease characteristics and established treatment strategies.

PURPOSE OF REVIEW: This review aims to detail the characteristics and outcomes of duodenal-type follicular lymphoma (DTFL), a rare lymphoma variant. It focuses on integrating recent reports in treatment modalities and highlights emerging insights into the unique biological features of the disease. RECENT FINDING: Recent studies confirm the indolent nature of DTFL, with extended follow-up periods showing favorable outcomes under watchful waiting strategies and a notable proportion of patients experiencing spontaneous remission. Additionally, advancements in understanding the disease's biology revealed that the tumor microenvironment is marked by specific genomic expressions indicative of chronic inflammation. SUMMARY: The observations of spontaneous resolution and the generally favorable progression of DTFL call for a conservative approach in initiating treatment. Clinical management should judiciously consider the disease's typically benign course against the potential risks of intervention, promoting customized treatment protocols tailored for cases with clinical necessity. Additionally, the discovery of an inflammatory tumor microenvironment and molecular evidence suggesting an antigen-driven process highlight critical areas for future research.

Nodular lymphocyte-predominant Hodgkin lymphoma characteristics, management of primary and relapsed/refractory disease and outcome analysis: the first comprehensive report from the Middle East.

BACKGROUND: Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is an uncommon variant of Hodgkin lymphoma. There is limited data on treatment, management of refractory and relapsed disease, and long-term outcome. Many registries or country-wide data reports are unable to provide detailed primary and subsequent management. We are reporting our observation on patient's characteristics, management, and outcome. METHODS: This single-institution retrospective cohort analysis includes NLPHL patients seen from 1998 to July 2019. We used Fisher's exact test, chi-square, and Kaplan-Meier (KM) method for various analyses. RESULTS: Two hundred patients were identified, (6.34% of all the HL). Male:female was 3:1. The median age at diagnosis was 22 years (4-79 years). Stage I-II in 145 (72.5%) cases. One hundred patients (50%) received chemotherapy, 68 (34%) chemotherapy + radiation therapy (RT); 87% of all chemotherapy was ABVD (adriamycin, bleomycin, vinblastine, dacarbazine). Thirteen patients (6.5%) received RT alone and 16 (8%) had surgery alone. Complete response in 82%, partial response in 5.5% and progressive disease in 10.5%. The median follow is 60 months (5-246). Median 5 and 10 years overall survival (OS) is 94.8 and 92.4% (stages I-II, 97.7 and 97.7%, stage III-IV, 94.8 and 92.4%). Median event-free survival (EFS) is 62.3 and 54% respectively (stage I-II, 72 and 64%, stage III-IV, 36.4 and 18.2%). Stage I-II vs III-IV OS (p = < 0.001) and EFS (p = < 0.001) were significant. For stage I-II, 5 year EFS of chemotherapy + RT (83.3%) was superior to chemotherapy alone (60%, p = 0.008). Five year EFS for early favorable (80%), early unfavorable (60%), and advanced (36.4%) was significant (p = < 0.001). Eleven patients (5.5%) had high-grade transformation. Twenty-nine patients underwent HDC auto-SCT, all are alive (28 in remission). 25% of patients had pathologically proved nodal hyperplasia at some point in time. CONCLUSION: OS of NLPHL is excellent and independent of treatment type. EFS is better for chemotherapy + RT than chemotherapy alone. Stem cell transplant in refractory / multiple relapses resulted in excellent disease control. There is a need to identify optimal treatment strategies accordingly to the risk stratification.

Spectrum of bone marrow pathology and hematological abnormalities in methylmalonic acidemia.

Patients with isolated methylmalonic acidemia (MMA) may present with a wide range of hematological complications including anemia, leukopenia, thrombocytopenia, and pancytopenia. However, there are very limited data on the development of hemophagocytosis or myelodysplasia in these patients. We report three patients with isolated MUT related MMA who presented with severe refractory pancytopenia during acute illness. Their bone marrow examination revealed a wide spectrum of pathology varying from bone marrow hypoplasia, hemophagocytosis to myelodysplasia with ring sideroblasts. We discuss their management and outcome. This report emphasizes the need for bone marrow examination in these patients with refractory or unexplained severe cytopenia, to confirm bone marrow pathology, and to rule out other diseases with similar clinical presentation for a better clinical outcome.

Cancer Vaccines: Past, Present, and Future.

Cancer is a common and potentially deadly disease. Some of the cancers may be difficult to treat by conventional means such as surgery, radiation, and chemotherapy, but may be controlled by the stimulation of the immune response of the body with the help of cancer vaccines. The use of vaccines for preventing infections by oncogenic viruses such as hepatitis B virus and human papilloma virus has been extremely successful in reducing the incidence of cancers resulting from these infections. The use of vaccines for treating cancers that are not due to viral infections and that are already established is currently the object of numerous clinical trials. Several types of cancer vaccines are being tried. These include antigen vaccines, tumor cell vaccines, dendritic vaccines, deoxyribonucleic acid vaccines, and viral vector vaccines. The development of these therapeutic vaccines is proving difficult with only 1 recent success. However, there is significant enthusiasm and optimism regarding the development of effective therapeutic vaccines stemming from the fact that our understanding regarding the cancer immunology is considerably enhanced in recent years. This expanded knowledge regarding the mechanisms that cancers use to escape the immune system is likely to open new avenues in modulating the immune response to cancer, thus enhancing the effectiveness of therapeutic cancer vaccines.

Intratubular germ cell neoplasia of the testis: a brief review.

Germ cell tumors of the testis may be divided into 3 broad categories according to age at presentation. The tumors in the pediatric age group include teratoma and yolk sac tumor. These tumors are generally not associated with convincing intratubular neoplasia. The second group consists of tumors presenting in third and fourth decade of life and include seminoma, embryonal carcinoma, yolk sac tumor, choriocarcinoma, and teratoma as well as mixed germ cell tumors. The precursor cell for these tumors is an abnormal gonocyte that fails to differentiate completely into spermatogonia. These abnormal cells stay dormant in the gonad during intrauterine life as well as infancy and childhood, but undergo proliferation during puberty and can be identified as intratubular germ cell neoplasia unclassified (IGCNU). These tumor cells continue to manifest protein expression pattern that resembles primitive germ cells (PLAP, c-KIT, OCT3/4). After a variable interval following puberty, IGCNU cells may acquire ability to penetrate the seminiferous tubules and present as an overt germ cell tumor. Acquisition of isochrome 12 and other genetic abnormalities are usually associated with this transition. The level of DNA methylation generally determines the phenotype of the germ cell tumor. The third type of germ cell tumors is spermatocytic seminoma, which is a rare tumor encountered later in life usually in fifth and sixth decade. The cell of origin of this tumor is probably postpubertal mature spermatogonia which acquire abnormal proliferative capability probably due to gain of chromosome 9 resulting in activation and amplification of genes such as DMRT1. The tumor cells manifest many of the proteins normally expressed by mature sperms such as VASA, SSX2, and occasionally OCT2. Although spermatocytic seminoma may also have an intratubular growth phase, it completely lacks features of IGCNU.

Diagnosis and Treatment of Subcutaneous Panniculitis-like T-cell Lymphoma: A Systematic Literature Review.

OBJECTIVES: The aim of this systematic review is to investigate different diagnostic methods and the available treatment options for subcutaneous panniculitis-like T-cell lymphoma (SPTCL). METHODS: We searched PubMed, Web of Science, SCOPUS, EBSCO, and CINAHL Plus for published case reports of SPTCL. From each record, we extracted data of the diagnostic methods, immunohistochemical profile, clinical characteristics, and the treatment approaches provided. Data were summarized and narratively synthesized to highlight the various diagnostic methods and treatment options of SPTCL. RESULTS: Our literature search yielded 1293 unique citations. Following screening, nine articles reporting a total of 15 cases were included in this systematic review. All patients presented with subcutaneous nodules. Three of the 15 cases were initially misdiagnosed. The atypical lymphoid cells were positive for CD2, CD3, granzyme B, and TIA-1 and negative for CD1a, EBER, and CD20 in all the reported cases. The atypical lymphoid cells were positive for CD45RO in four out of seven cases, positive for CD56 in three out of 12 cases tested, while positive for CD5 and CD8 in the majority of cases. Therapy ranged from topical agents to immunosuppressive agents all the way to multiagent chemotherapy. CONCLUSION: SPTCL is a rare lymphoma. Diagnosis is highly dependent on the immunohistochemical stains added to histopathologic and radiologic findings. Therapy is dependent on the pace of the disease, with encouraging results obtained with single-agent cyclosporine.

Hematologic reference intervals for healthy adult Saudis in Riyadh.

BACKGROUND: Laboratory hematological tests are widely used in clinical practice to assess health and disease conditions. Reference ranges provided by laboratory reports are considered the most authoritative medical tools to assist in the decision-making phase. International standards institutes recommend that reference ranges be established for each region. OBJECTIVES: Provide reference values of routine hematological parameters in Saudi adults according to age and gender. DESIGN: Cross-sectional SETTING: Central province of Saudi Arabia. PATIENTS AND METHODS: Apparently healthy Saudi adults were subjected to laboratory testing of routine hematological parameters (full blood count, hemostatic profile, and serum hematinics), after completing a detailed health medical questionnaire. MAIN OUTCOME MEASURES: Hematological reference values based on the local population. SAMPLE SIZE AND CHARACTERISTICS: 637 after screening 827 potentially healthy Saudi adults with ages ranging from 15 to 65 years. RESULTS: The reference values of routine hematological parameters for the full population and by gender are presented with 90% CI as the lower and upper limits. Reference ranges mostly differed from universal established ranges shown in textbooks. CONCLUSION: The reference ranges of routine hematologic parameters for accurate assessment and appropriate management will help improve the routine clinical care of the adult Saudi population. LIMITATIONS: Difficulty in assessing health status of participants, who could have subclinical illnesses not reflected in the evaluated blood measurement. Lack of ability to eliminate individuals who might be carriers for haemoglobinopathies. Studies with larger sample sizes from different areas of the country are required to achieve a more accurate representation of the whole Saudi population. CONFLICT OF INTEREST: None.

Spectrum of Myelodysplastic Syndrome in Patients Evaluated for Cytopenia(s). A Report from a Reference Centre in Saudi Arabia.

BACKGROUND/OBJECTIVE: Myelodysplastic syndrome (MDS) is a clonal disorder of hematopoietic stem cells, characterized by ineffective hematopoiesis, peripheral cytopenias along with hypercellularity of the bone marrow, and marked dysplastic features. Establishing MDS diagnosis is difficult due to nonspecific clinical presentation and imprecise morphological criteria. In anticipation to improve the diagnostic approach in this field, we aimed to characterize the clinical and morphological features of patients presented with cytopenias with a special focus on MDS. METHODS: We comprehensively reviewed all medical record of patients who were referred to the hematology laboratory at KFSH-RC, Riyadh, Saudi Arabia, between January 2009 and March 2016 for evaluation of bone marrow aspirates and trephine biopsies due to severe and persistent cytopenia(s) to rule out MDS. RESULTS: A total of 183 patients, 155 adult and 28 pediatric, were identified. In the adult group, MDS was diagnosed in 82 (52.9%) patients, with a male-to-female (M:F) ratio of 1.6:1 and mean age at diagnosis of 50 years. According to the World Health Organization (WHO) 2017 criteria, MDS subtypes were as follows: MDS with single lineage dysplasia (SLD, 5%), MDS with ring sideroblasts and SLD (MDS-RS-SLD 7%), MDS with multilineage dysplasia (MDS-MLD 21%), MDS with deletion of chromosome 5q (MDS del(5q), 2%), MDS unclassifiable (MDS-U7%), hypoplastic MDS (h-MDS 4%), MDS with excess blasts-1 (MDS-EB1, 20%), MDS with excess blasts-2 (MDS-EB2, 28%), and therapy-related MDS (6%). Laboratory and morphological features were described. In both groups, cytogenetic abnormalities were classified according to the Revised International Prognostic Scoring System cytogenetic risk groups. In adults, the dominating cytogenetic abnormalities were monosomy 5 and monosomy 7 seen in 20.7% and 24.4% of patients, respectively. Peripheral cytopenia not due to MDS was diagnosed in 54 (34.8%) patients, with a mean age of 43 years and M:F ratio of 1:1. The cause of these cytopenias were as follows: bone marrow failure (BMF, 22%), peripheral destruction (20%), drug induced (20%), anemia of chronic disease (16%), B12 deficiency (7%), infection (7%), paroxysmal nocturnal hemoglobinuria (4%), idiopathic cytopenia of undetermined significance (2%), and idiopathic dysplasia of undetermined significance (2%). A definite diagnosis of MDS was not possible in 19 patients due to insufficient clinical data. In the pediatric group, MDS was diagnosed in 14/28 (50%) patients, with M:F ratio of 1.8:1 and mean age at diagnosis of 4 years. MDS subtypes (WHO 2017) in 14 patients were as follows: refractory cytopenia of childhood (RCC, 42.8%), MDS-EB1 (42.8%), and MDS-EB2 (14.2%). Laboratory and morphological features were described. The prevalent cytogenetic abnormality was monosomy 7 in six/14 (42.8%) patients. Cytopenias due to other causes were diagnosed in eight/28 patients (28.5%), with a mean age of 6.5 years and M:F ratio of 1.6:1. The causes of non-MDS related cytopenia were: congenital BMF (4 patients), peripheral destruction (2 patients), immune deficiency (1 patient), and viral infection (1 patient). A definite diagnosis of MDS could not be made in six/28 (21.4%) patients. CONCLUSION: MDS is the cause of cytopenia in a significant number of patients referred for evaluation of cytopenias, appears at younger age, and tends to be more aggressive than that reported in international studies. Anemia, dysplastic neutrophils in the peripheral blood, and dysplastic megakaryocytes in the bone marrow trephine biopsy are the most reliable features in distinguishing MDS from other alternative diagnoses.

FDG PET/CT in the Evaluation of a Rare Case of Multisystem Involvement in Newly Diagnosed Rosai-Dorfman-Destombes Disease.

Rosai-Dorfman-Destombes disease (RDD) is a rare histocytic disorder with a broad spectrum of clinical presentations. The disease typically presents with lymphadenopathy but may involve multiple systems. Usually, RDD lesions demonstrate intense 18F-Fluorodeoxyglucose (FDG) uptake in positron emission tomography/computed tomography (PET/CT) imaging due to the inflammation and infiltration with high metabolic process of the disease. Here, we describe a rare case of 37-year-old man who presented with multiple systemic symptoms, including fever, weight loss and bilateral cervical, and inguinal lymphadenopathy who underwent FDG PET/CT for detection of disease extension. This case highlights the role of FDG PET/CT in establishing the disease extent in newly diagnosed RDD and guiding the therapeutic recommendations and for follow-up to monitor the disease response to therapy. To the best of our knowledge, this is the first case report from Saudi Arabia highlighting the role of FDG PET/CT in newly diagnosed RDD.

Iacta Alea Est: The Inexorable Advance of Tofacitinib in the Treatment of Dermatomyositis-Associated Rapidly Progressive Interstitial Lung Disease. A Case Report.

Rapidly progressive interstitial lung disease is typically associated with clinically amyopathic dermatomyositis and the anti-melanoma differentiation associated gene 5 antibody, a condition with high mortality and resistance to classic immunosuppression. Recent reports have described the efficacy of the Janus kinase inhibitor tofacitinib in the treatment of rapidly progressive interstitial lung disease in anti-melanoma differentiation associated gene 5 antibody-positive clinically amyopathic dermatomyositis. It is uncertain, however, whether tofacitinib alters the course of rapidly progressive interstitial lung disease in other variants of dermatomyositis that are unrelated to the anti-melanoma differentiation associated gene 5 antibody and whether the early addition of the anti-fibrotic tyrosine kinase inhibitor nintedanib interferes with the development of fibrosis. To answer these questions, we present and discuss the case of an elderly woman who presented with a flare of dermatomyositis sine myositis. Based upon the detection of anti-Jo-1 antibodies and the absence of anti-melanoma differentiation associated gene 5 antibodies, anti-synthetase syndrome was diagnosed. While the cutaneous manifestations quickly resolved with prednisone, azathioprine and tacrolimus, the respiratory function paradoxically and rapidly deteriorated, and invoked the use of tofacitinib. Markedly raised ferritin levels and a severe numerical deficiency of circulating natural killer cells paralleled the acute lung inflammation, which was reflected by 18F-fluorodeoxyglucose hypermetabolism on positron emission tomography/CT. Tofacitinib lead to a prompt clinical recovery, with a reduction in oxygen requirement, correction of hyperferritinemia, reversal of the natural killer cell deficiency, and a decrease in 18F-fluorodeoxyglucose uptake in the affected lung segments. Subsequently, nintedanib was added at a point in time when inflammation subsided. Apart from cytomegalovirus reactivation no adverse events occurred. In conclusion, tofacitinib reversed the pronounced inflammatory component of anti-Jo-1 antibody-positive, anti-melanoma differentiation associated gene 5 antibody-negative rapidly progressive interstitial lung disease, confirming that Janus kinase signaling pathways are critically involved in the pathogenesis of rapidly progressive interstitial lung disease, apparently independently of the targeted autoantigen. Although some improvement in pulmonary function was observed, it seems premature to conclusively judge on reversibility or prevention of pulmonary fibrosis by pairing both kinase inhibitors for which an extended follow-up and ideally, prospective and controlled studies are needed.

Tubulocystic renal cell carcinoma with poorly differentiated foci and loss of fumarate hydratase: A case report.

Tubulocystic renal cell carcinoma (RCC) is one of the newly recognized subtypes of RCC. It has a unique cystic morphology and indolent behavior. During the last decade, few studies have been published describing tubulocystic RCC with poorly differentiated foci. A subset of these cases are associated with loss of fumarate hydratase which is a characteristic feature of hereditary leiomyomatosis and renal cell carcinoma-associated RCC. However, these two entities represent two distinct subtypes of RCC in the recent WHO Classification of kidney tumors. Herein, we are describing a rare case of tubulocystic renal cell carcinoma with poorly differentiated foci and loss of fumarate hydratase.

A Young Man With a Neck Mass and Hypereosinophilia.

A 31-year-old man presented with left cervical and left inguinal masses and intermittent itching and night sweats for 2 years. What is your diagnosis?

Teratoid Wilms Tumor: Report of Three Cases and Review of the Literature.

Teratoid Wilms tumor is a rare variant of Wilms tumor composed predominantly of well-differentiated epithelial and/or mesenchymal heterologous elements. Like the classical Wilms tumor, this variant may also occur as a renal mass or may be found in extra renal locations. This tumor may be treated effectively by surgical resection; however, it generally fails to respond to chemotherapy. A review of the literature revealed 30 reported cases of intra renal and 5 reports of extra renal teratoid Wilms tumor. We report our experience with an additional three cases of renal teratoid Wilms tumor adding to the 30 cases previously reported.

Atypical distinctive dermal clear cell mesenchymal neoplasm arising in the scalp.

Distinctive dermal clear cell mesenchymal neoplasm (DDCCMN) is a newly described entity characterized by a dermal proliferation of neoplastic cells with clear to reticulated cytoplasm and vesicular nuclei. Atypical features in the form of nuclear pleomorphism and mitoses may be found. The histogenesis of these neoplastic clear cells is not currently known but they are thought to be mesenchymal in origin. Immunohistochemically, they stain positively for NKI-C3 and negatively for melanocytic, epithelial and lymphoid markers. All five cases originally reported by Lazar and Fletcher occurred in the lower extremities. We report herein a case of DDCCMN with atypical features arising in the scalp.

Incidentally Discovered Persistent Müllerian Duct Syndrome in a 45-year-old male presenting with germ cell tumor and bilateral cryptorchidism: A rare case report and review of the literature.

INTRODUCTION: Persistent Müllerian Duct Syndrome (PMDS) is a rare sexual disease. It is characterized by the presence of female reproductive structures such as uterus, cervix, fallopian tubes and upper part of vagina in a normal genotypically and phenotypically male. The diagnosis is usually incidental since the patients will present with normal external genitalia and secondary sexual characteristics. Imaging techniques such as magnetic resonance imaging (MRI), computed tomography (CT) scan, or ultrasound (US) could help in the diagnosis. CASE PRESENTATION: A 45-year-old male presented with bilateral undescended testes since birth and 2 months history abdominal mass. CT scan showed a 13 × 17 × 20 cm solid pelvi-abdominal mass. The diagnosis of mixed germ cell tumor of the undescended testes was made based on the CT scan. During resection of the tumor, patient was found to have a uterus, fallopian tubes and ovaries. DISCUSSION: Pathological investigation showed endometrial tissues with portion of lower uterine segment and cervix with remnant of testes with marked atrophy. No Ovarian tissues were found nor fallopian tube as well. The diagnosis of PMDS was made based on the pathological report. CONCLUSION: PMDS is a challenging condition to diagnose. Radiological investigation can miss the presence of the Müllerian duct structures as in our case because of the unusual presentation of this condition. Early diagnosis and management is important as the malignant transformation is high due to the undescended testes.

The effect of freezing and long-term storage on the stability of cardiac troponin T.

Cardiac troponin T (cTnT) levels are widely used to assess for evidence of myocardial infarction. We studied the effect of freezing and long-term storage on the stability of cTnT in blood samples from 178 patients with end-stage renal failure. The serum was separated and divided into multiple aliquots. Baseline cTnT levels were measured in the unfrozen aliquots. The remaining aliquots were frozen using standard techniques. The aliquots were thawed after 3, 6, 12, or 24 months and cTnT levels measured. There were no significant changes in the mean +/- SEM cTnT levels up to 12 months (0.111 +/- 0.098 microg/L) compared with baseline (0.114 +/- 0.098 microg/L); after 24 months, cTnT levels were significantly lower (0.107 +/- 0.095 microg/L) than baseline ( P = .004). The cTnT assay is a reliable method of measuring the cTnT level in human serum up to 12 months of frozen storage. However, after 24 months, the cTnT level was 0.007 microg/L lower than baseline, potentially causing erroneous interpretations. The clinical significance of the change in the cTnT level after long-term frozen storage is unclear. Further studies, including prospective analysis of patient outcomes, should be helpful.

Expression of renal cell carcinoma antigen (RCC) in renal epithelial and nonrenal tumors: diagnostic Implications.

Antibody to renal cell carcinoma (RCC) antigen, a normal human proximal brush border antigen, has recently become commercially available and reported to be highly specific and a relatively sensitive marker for RCC. Of the nonrenal tumors occasional carcinomas have been reported to express RCC, notably breast carcinoma. Using tissue microarrays, we investigated the use of RCC on a large number of renal epithelial neoplasms (RENs) and nonrenal tumors, especially those potentially confused with REN. Three tissue microarrays containing 241 REN samples, 192 samples of a wide variety of neoplasms and 170 adrenal tumor samples, respectively, were stained with RCC monoclonal antibody. RCC expression was scored for staining intensity and percentage expression. Out of 241 REN, 173 were positive for RCC (sensitivity 72%): clear cell 72%, papillary 95%, chromophobe 91%, unclassified 85%, oncocytoma 75%, sarcomatoid 20%, and metastatic RCC 40%. The overall immunostaining intensity was consistently much higher in papillary and clear cell RCC than in other tumors. Seventy-six out of 362 nonrenal tumor samples demonstrated either focal or diffuse expression for RCC (specificity 79%). These included: adrenocortical neoplasms 37/170 (22%), colonic 11/29 (37.5%), breast 9/27 (33%), prostate 5/18 (27.7%), ovary 2/17 (11.7%), melanoma 3/18 (16.6%), lung 3/21 (14.2%), and parathyroid 3/3 (100%). RCC expression was seen equally among adrenal adenoma and carcinoma group. Eight out of 28 (28.5%) normal adrenal cores also stained for RCC. RCC is a relatively useful marker in the differential diagnosis of REN only if used in a panel with other positive and negative markers. RCC does not reliably differentiate REN, especially classic clear cell type, from adrenocortical neoplasms, which are frequently confused due to close anatomic proximity and similar morphology. RCC also does not reliably differentiate subtypes of renal epithelial neoplasms.

ALK-positive anaplastic large cell lymphoma with primary bone involvement in children.

We describe the clinical, radiologic, and pathologic features of primary bone anaplastic large cell lymphoma (ALCL) in 3 boys. Radiologic imaging showed lytic lesions involving sacrum, femur, or rib. Bone was the only site of disease in 2 cases; an associated partial lymph node was involved in case 3. Differential diagnoses included osteomyelitis and small round cell tumors of childhood, particularly Ewing sarcoma. Preoperatively, ALCL was not a diagnostic consideration in any case. Two cases showed classic large pleomorphic cells; 1 showed a composite pattern with a distinct small cell component and the more typical large cell type. Neoplastic cells in all cases showed strong CD30 and anaplastic lymphoma kinase expression with relatively weak epithelial membrane antigen positivity. Cytotoxic granule protein was expressed in 2 cases. All cases showed unusually strong expression of neuron-specific enolase (NSE). Two patients were disease-free at last follow-up (15 months and 11 years); 1 patient died of disseminated disease within a year of diagnosis. ALCL should be considered a diagnostic possibility when evaluating neoplastic bone lesions in children. Although expression of NSE in ALCL has not been emphasized in the literature, it is worth noting because it may pose a diagnostic pitfall.