[Eight-year experience in treating aggressive mediastinal large B-cell lymphomas].

AIM: To make a differential diagnosis of diffuse large B-cell lymphoma (DLBCL) with primary involvement of the mediastinal lymph nodes (LN) and primary mediastinal large B-cell lymphoma (PMLBCL); to evaluate the efficiency of a modified NHL-BFM-90 (M-NHL-BFM-90) program in the treatment of the above nosological entities. SUBJECTS AND METHODS: The investigation enrolled 60 patients with large B-cell lymphoma (LBCL) with primary involvement of mediastinal LN who had been treated at the Hematology Research Center, Ministry of Health of Russia, in 2004 to 2012. The diagnosis of PMLBCL and DLBCL with primary involvement of mediastinal LN was based on histological findings, the phenotype of tumor cells, and molecular evidence. Treatment was performed according to the M-NHL-BFM-90 program. Three pregnant women received predelivery polychemotherapy (PCT) according to the VACOP-B protocol and continued to have a DexaBEAM chemotherapy regimen 3-4 weeks postpartum. In case of a residual mass, all the patients underwent consolidation radiotherapy to the mediastinal area in a total focal dose of 36 Gy. RESULTS: The diagnosis of PMLBCL was established in 39 patients: 10 men and 29 women whose ages were 18 to 60 years (median age 30 years); DLBCL with primary involvement of mediastinal LN was verified in 21 patients: 8 men and 13 women whose age was 21 to 70 years (median age 30 years). After m-NHL-BFM-90 treatment protocol, 5-year overall survival rates in the patients with DLBCL with primary involvement of mediastinal LN and in those with PMLBCL were 95+/-5 and 86+/-6% and 5-year event-free survival rates were 95+/-5 and 78+/-7%, respectively. All the pregnant women diagnosed with PMLBCL who had received the VACOP-B --> delivery--> Dexa-BEAM PCT regimen during pregnancy achieved remission. The follow-up periods were 30, 36, and 42 weeks. CONCLUSION: The patients with new-onset LBCL and primary involvement of mediastinal LN are a heterogeneous group that includes patients having two different diagnoses: PMLBCL and DLBCL. The efficiency of high-dose PCT is different in the patients with DLBCL with primary involvement of mediastinal LN and in those with PMLBCL (in spite of their similar clinical features, similar epidemiological characteristics, and the presence of the same unfavorable prognostic factors at onset).

[The specific features of renal lesion in Burkitt's lymphoma].

AIM: To analyze the causes of renal lesion in patients with Burkitt's lymphoma (BL) and to develop optimal treatment policy. MATERIALS AND METHODS: The data of examination and treatment were analyzed in 20 patients with BL (14 men and 6 women aged 15 to 57 years (median age 24 years)) who had been followed up for renal lesion at the Hematology Research Center (HRC) in 2003 to 2011. When admitted to hospital, all the patients were found to have ureteric compression, renal parenchymal tumor infiltration, massive tumor cytolysis syndrome (MTCS). Polychemotherapy (PCT) was performed in accordance with the original intensive BL-M-04 protocol. The extent of the process was estimated according to the classification developed by S.B.Murphy: L3 variant B of acute lymphoblastic leukemia in 10 cases; Stage IV in 2; Stage III in 8. Acute renal failure (ARF) was identified in 13 patients. A control group comprised 36 patients with BL without ARF who had been followed up at the HRC in 2003 to 2011 and included into the BL-M-04 protocol. The ratio of patients with bone marrow lesion was 7:13 and 9:36 in the BL + ARF and BL-ARF groups, respectively. RESULTS: Decreased urine specific gravity and proteinuria (0.4 to 1.3 g/l) were the first manifestations of renal lesion and were seen in approximately 50% of all cases both on admission to hospital and in the first stages of PCT (10 and 9, 8 and 7 of the 20 cases, respectively). Microhematuria more commonly developed after initiation of PCT (7 and 3 of the 20 cases, respectively). ARF was diagnosed in 13 patients (24% of the 55 BL patients followed up at HRC in 2003 to 2011). One female patient developed ARF after the start of PCT. Twelve patients developed this condition at the onset of disease; in 4 patients, ARF existing prior to PCT began progressing after drug administration. The etiology of ARF was generally mixed. At the onset of disease, MTCS (n = 6) and specific renal parenchymal infiltration (n=6) were more common causes of ARF. Postrenal anuria was present in 2 cases. ARF after PCT initiation resulted from the toxic effects of methotrexate and MTCS (3 and 4 cases, respectively). ARF regressed in the early periods: in the prophase (n = 4) and during or the first PCT block A (n = 9). The BL patients with ARF, as compared to those without the latter, showed a statistically significant earlier onset of myelotoxic agranulocytosis (MTA): on day 3 of an intercourse interval (95 CI from 0 to 3 days) versus its day 5 (95% CI from 2 to 5 days) and a statistically significant longer duration of MTA--12 days (95% CI from 7 to 16 days) versus 7 days (95% Cl from 3 to 10 days); they were observed to have more severe mucositis. Despite the longer intercourse interval, 10 patients with ARF achieved remission; 4 patients died from therapy-refractory sepsis and 1 patient from thrombocytopenia. In the patients with ARF, mortality rates were significantly higher than in those without ARF (33% versus 10%; p = 0.04). CONCLUSION: Although there is a high risk of worsening renal dysfunction, PCT is a necessary condition for ARF resolution in BL.

[Primary lymphomas of bones and soft tissues: comparative assessment of treatment results].

AIM: To evaluate the efficiency of intensive polychemotherapy (PCT) in adult patients having diffuse large B-cell lymphoma (DLBL) of bones and soft tissues with and without poor prognostic factors (PPF). SUBJECTS AND METHODS: Out of 58 enrolled patients, 51 were diagnosed as having DLBL. Burkitt's lymphoma (BL) was diagnosed in 6 patients. One patient had marginal zone B-cell lymphoma. Thirty-five patients with DLBL (10 patients with PPF and 25 without PPF) and 3 patients with BL were treated with the CHOP/R-CHOP regimen. The NHL-BFM-90 program was used in 3 patients with BL and 16 with DLBL (15 patients with PPF and 1 patient without PPF). RESULTS: After radiotherapy, the patient with marginal zone B-cell lymphoma achieved a 20-month remission; three BL patients receiving CHOP died. All the BL patients receiving NHL-BFM-90 achieved complete remissions of 48 to 72 months. In 9 patients having DLBL without PPF, who received CHOP, five-year overall and event-free survival rates were 100%; in 22 patients with PPF, these were 50 and 45%, respectively. In the patients with and without PPF, who received CHOP/R-CHOP, the survival rates differed statistically significantly (p = 0.01; logrank test). In the group of 15 patients having DLBL with PPF, who were treated with the NHL-BFM-90 protocol, 14 achieved an average remission of 17 months. In the patients having DLBL with PPF who used NHF-BFM-90, therapeutic efficiency was significantly higher (p = 0.05; Fisher's exact test). CONCLUSION: Differential therapy for primary lymphomas of bones and soft tissues indicated that the NHL-BFM-90 protocol used in the PPF group was significantly more effective than the CHOP regimens.

[Nine-year experience in the treatment of patients with diffuse large B-cell lymphosarcoma].

AIM: To ascertain indications to standard (CHOP-21/R-CHOP-21) and intensive (mNHL-BFM-90) treatment in patients with diffuse large B-cell lymphosarcoma (DLBCL) with involvement of lymphoid organs. MATERIAL AND METHODS: The trial, performed from January 2002 to December 2010, enrolled 139 DLBCL patients with affected lymph nodes (LN), tonsils, spleen, bone marrow (BM). The diagnosis was made according to WHO criteria. The patients were examined according to the protocol of lymphoproliferative diseases. Biopsy material from all 139 patients was studied immunohistochemically on paraffin blocks (LN, tonsils, spleen, BM) using a wide panel of antibodies. The same examinations of BM were made in all 18 cases of BM involvement. Cytogenetic examination was performed in 106 patients: 48 standard cytogenetic tests, 139 - FISH for t (14;18) as well as rearrangement of locus 3q27. Patients with a poor prognosis (n = 86, 61.8%) received intensive therapy according to mNHL-BFM-90 program. The signs of a poor prognosis were the following: massive tumor (tumor size more than 7.5 cm), invasion into the adjacent organs or tissues, stage III-IV disease by Enn-Erbor, high concentration of LDG. Patients without a poor prognosis (n = 53, 38.2%) received standard treatment CHOP-21 (n = 28) or R-CHOP-21 (n = 25). RESULTS: A complete remission without recurrences was achieved in all 53 patients without signs of unfavourable prognosis (100%). Overall 5-year survival was 96%, 2 patients died in remission of other causes. Of 86 patients with a poor prognosis a complete remission was achieved in 64 (74.4%) patients. Overall and recurrence-free 5-year survival was 65 and 86%, respectively. CONCLUSION: Standard treatment provided long-term complete remission in all the patients without poor prognosis. Intensive (mNHL-BFM-90) treatment produced the best results in generalized lesion without BM involvement. Overall 5-year survival was 84% in these patients and 12% in patients with BM involvement.

[Differential diagnosis of thymic hyperplasia and mediastinal tumor in patients with lymphogranulomatosis after chemotherapy].

AIM: To make differential diagnosis of thymic hyperplasia and mediastinal tumor after chemotherapy (CT) in patients with Hodgkin's disease (HD). MATERIAL AND METHODS: The examination of 182 HD patients aged 16-71 years (median 28 years) included chest x-ray computed tomography (XCT) at baseline, during treatment, each 3 months, ultrasound investigation of the chest and abdominal cavity. All the patients received 6-8 courses of the treatment according to the program BEACOPP-14 followed by radiotherapy on the residual tumor in 137 patients, or not followed in 45patients. RESULTS: Soft tissue tumor in the anterior mediastinum was detected in 14 (31%) from 45 unirradiated patients (age 19-31 years, median 24 years) 1 to 10 months (median 3.5 months) after chemotherapy. The analysis of the data of ultrasound investigation and tomography identified a mediastinal lesion as thymic hyperplasia. The patients are now in remission with follow-up median 21 months (13-36 months). No recurrence was registered. CONCLUSION: Young HD patients with unirradiated mediastinum develop thymic hyperplasia in 31% cases within one year after chemotherapy. In view of this, detection of the lesion in the anterior mediastinum after CT demands complex examination for differential diagnosis of thymic hyperplasia with tumor recurrence to avoid unwanted intensification of the treatment.

[Diffuse large B-cell lymphoma with primary involvement of mediastinal lymph nodes: diagnosis and treatment].

AIM: To diagnose diffuse large B-cell lymphosarcoma (DLBCLS) with primary involvement of the mediastinal lymph nodes (LN) and to evaluate the efficiency of aggressive polychemotherapy (PCT). SUBJECTS AND METHODS: The study included 15 patients (6 men and 9 women aged 18 to 70 years; median 38 years) followed up at the Hematology Research Center, Russian Academy of Medical Sciences, in 2004 to 2009. Three and 12 patients had Stages II and IE DLBCLS, respectively. B symptoms were found in 14 (93.4%) patients. Increased lactate dehydrogenase (LDH) concentrations were detectable in 14 (93.4%) patients; tumors of 10 cm or more (bulky disease) were seen in 11 (73.3%). Enlarged cervical, supraclavicular, and axillary lymph nodes were found in 9 (60%) patients; lung involvement via extension in 9 (60%), and invasion into the pericardium in 5 (33.3%) and soft tissues of the anterior thoracic wall in (13.3%). There were no signs of involvement of extranodal organs at the moment of diagnosis. All the 15 patients received PCT according to the modified NHL-BFM-90 program: 4 to 6 courses depending on the response to the therapy; 10 (66.6%) and 5 (33.3%) patients had 4 and 6 courses, respectively; for consolidating purpose, 11 (78.5%) patients were prescribed radiotherapy applied to the mediastinum in a cumulative dose of 36 Gy due to the fact that they had a residual mass. RESULTS: Thirteen (86.6%) patients achieved a complete remission (CR). Primary PCT resistance was confirmed in one case. Another patient was stated to have near-complete remission. No recurrences were notified during the follow-up. The mean CR duration was 24.5 (range 2-49) months. CONCLUSION: DLBCLS with primary LN involvement is an individual nosological entity to be differentiated from primary mediastinal large B-cell lymphosarcoma. In most cases, DLBCLS shows signs of a poor prognosis, which makes it necessary to perform aggressive PCT.

[Clinical and epidemiological features of Burkitt's lymphoma].

AIM: To characterize clinical and epidemiological features of adult Berkitt's lymphoma (BL). MATERIAL AND METHODS: The trial enrolled 72 patients (51 males and 21 females, age 14-69, mean age 27 years) treated in 1995-2008. RESULTS: Stage I BL (by S.B. Murphy) was diagnosed in 5 patients, stage II--in 9, stage III--in 25, IV--in 14 patients, B-cell acute lymphoblastic leukemia (ALL) (L3)--in 19 patients. Intoxication was seen in 56 (78%) patients, 38% patients had severe cachexia. Elevated concentration of lactatedehydrogenase (LDG) was detected in 57 (79%) patients. In all the cases clinical symptoms developed for 1-3 months, median 6 weeks. Bone marrow involvement was diagnosed in 22 (31%) patients, CNS was affected in 17 (24%) patients, of them 14 were males. Fifty two (72%) patients had abdominal, retroperitoneal and/or small pelvis tumors. Intestinal, hepatic, renal and gastric tumors occurred most frequently. Specific ascitis was detected in 25 (48%), tumor pleuritis--in 11 (15%) patients. BL of the facial skeleton, Waldeyer's ring, oro- and nasopharynx was in 12 (17%) patients. Seven patients had concomitant involvement of the CNS. Eight (38%) and 2 (10%) women had tumors of the ovaries and uterus, respectively. CONCLUSION: BL is characterized by the following clinical features: young age of the patients, most of them are males, B-symptoms, short history, generalized stages, extranodal lesions, firequent involvement of the bone marrow and CNS.

[High-dose polychemotherapy of patients with poor-prognosis anaplastic T.0-large cell ALK+ lymphosarcoma].

AIM: To evaluate efficacy of the protocol NHL BFM-90 in the treatment of adult anaplastic large cell lymphosarcoma (ALCL) ALK+ and validity of addition of transplantation of autologous stem hemopoietic cells (ASHC) into first line treatment. MATERIAL AND METHODS: We treated 13 patients with stage III-IV ALCL ALK+. The age of the patients ranged from 17 to 44 years (median 26 years). The diagnosis was made using morphological, histological, immunohistochemical methods with application of monoclonal antibodies to CD30, ALK, CD3, CD4, CD8, CD7, CD34, CD15, CD68, CD20, CD45RO, CD45RA. The patients were treated according to the protocol NHL BFM-90. ASHC was made in two patients with the disease stage IV. RESULTS: We obtained a complete remission in 12 of 13 patients, one woman died of infectious complications in the beginning of the treatment, one man had early recurrence 45 days after the end of the treatment with lethal outcome and disease progression. Two patients at stage IV and poor prognosis had undergone ASHC transplantation. They are now in remission for 5 and 12 months. CONCLUSION: ALCL ALK+ is characterized by an aggressive clinical course (11 of 13 patients had stage III-IV), high rate of extranodal lesions. Twelve patients achieved a complete remission, 11 (91.6%) of 12 patients are alive in observation median 27 months. We effectively used ASHC transplantation in the first-line treatment of 2 patients with stage IV of the disease and poor prognosis.

[Diagnosis and treatment of skin T-cell lymphoma undergoing transformation in lymphosarcoma].

AIM: To define complex of parameters characterizing transformation of skin T-cell tumors in lymphosarcoma; to show specific treatment of patients with this transformation. MATERIAL AND METHODS: Of 57 patients with primary T-cell lymphomas of the skin (mycosis fungoides, Sezary's disease), we studied 12 patients with transformation of the process into lymphosarcoma by clinical, histological, moleculobiological and immunophenotypical parameters. RESULTS: We found that transformation of T-cell lymphoma into lymphosarcoma occurred in different time from the disease onset (2-12 years). In patients with mycosis fungoides (MF) the transformation was local while in those with Sezary's disease (SD) transformation of the tumor clone was determined by appearance of peripheral blood tumor cells rejuvenation. Morphological alterations were accompanied with immunomorphological parameters of progression. Most significant of them were high expression of the proliferative activity marker Ki-67 (10-70%), enhancement of activation (CD30, CD25), loss of some linear T-cell markers. Treatment of lymphosarcoma arising on the background of lingering MF or SD may combine two types of antitumor treatment--intensive and supporting because of coexistence of different clones of one tumor. CONCLUSION: Verification of skin T-cell lymphoma diagnosis and its transformation into lymphosarcoma must be based on the evidence from a number of examinations: histological, immunophenotyping, moleculobiological and clinical. Among criteria of the transformation, markers of lymphoproliferative activation are of great importance.

[First experience of using modified program NHL-BFM-90 for the treatment of primary diffuse large-B-cell lymphosarcoma of the bones and soft tissues with poor-prognosis].

AIM: To evaluate efficacy of intensive modified program NHL-BFM-90 (mNHL-BFM-90) in adult poor-prognosis patients with diffuse large B-cell lymphosarcoma (DLBCL) of the bones and soft tissues. MATERIAL AND METHODS: The mNHL-BFM-90 program was used in the treatment of 3 male and 2 female patients aged 17-69 years (median 42 years). Four patients had DLBCL of the bones and one patient--DLBCL of the soft tissues. All the patients had tumors more than 10 cm in size. B-symptoms, a high concentration of lactate dehydrogenase (LDG) were registered in 3 patients. One patient had stage IE by Ann-Arbor, two--stage IIE (involvement of regional lymph nodes), two--stage ME (multiple bone lesions). A total of 4-6 blocks of polychemotherapy according to mNHL-BFM-90 program were performed. RESULTS: Complete remissions were achieved in all the patients. They had no recurrences after 6 to 20 month (median 13 months) follow-up. CONCLUSION: Positive results of the program mNHL-BFM-90 in poor-prognosis patients with DLBCL of the bones and tissues necessitate further studies of this therapy.

[First experience of using modified high-dose therapy NHL-BFM-90 in diffuse large B-cell lymphosarcoma with primary skin involvement. A case report].

Primary skin large B-cell lymphosarcomas (PLBCL) present with skin lesions, other organs and systems are not involved. As CHOP courses are not high effective in PLBCL, we were the first to treat a patient with modified block therapy NHL BFM-90. A complete remission was achieved after the first course of polychemotherapy and was consolidated by two courses of treatment. Further follow-up is needed.

[Tumor development from follicular dendritic cells in a hyaline-vascular variant of Castleman's disease].

Literature gives only few reports of hyaline-vascular variant of Castleman's disease associated with tumor from dendritic cells. A case of simultaneous detection of these diseases in the tumor located in the retroperitoneal space and successfully removed surgically is reported.

[Primary lymphoproliferative diseases of the central nervous system].

Primary CNS lymphomas have worse prognosis than other extranodal lymphomas: remissions are rare, recurrences are frequent. Literature is analysed on diagnosis, prognostic factors, perspectives and problems of treatment of primary CNS lymphomas.

[High-dose therapy of Burkitt's lymphoma in patients over 40 years of age].

AIM: To analyse efficacy and tolerance of high-dose polychemotherapy (PCT) of Berkitt's lymphoma (BL) in patients aged over 40 years. MATERIAL AND METHODS: High-dose PCT was given to 6 BL patients aged 41-56 years (median 48.1 years). RESULTS: Complete clinicohematological remissions were achieved in 4 patients. In two of them the treatment was discontinued after three blocks of PCT because of severe infectious complications. According to 4-12 month follow-up, remission continues. Remission was not achieved in two patients: one patient had primary resistance, the other died of sepsis after the second PCT course before remission. The time to remission did not correlate with age. Duration of myelotoxic agranulocytosis varied from 2 to 24 days. Duration of agranulocytosis did not correlate with age. Infections complicated 19 of 20 PCT blocks. Severity of complications caused withdrawal of three patients. CONCLUSION: BL is biologically heterogenous as it demonstrates different responses to BL-M-04 program. Causes of slow regression of tumor mass in some patients need further investigations. In spite of a great number of infectious complications high-dose therapy has no alternative.

[Efficacy of conservative treatment of gastric lymphosarcoma].

AIM: To compare efficacy and toxicity of conservative therapy (different programs of polychemotherapy) of gastric lymphosarcoma conducted for the last 10 years in Hematological Research Center of the Russian Academy of Medical Sciences. MATERIAL AND METHODS: The study included 63 patients (40 females and 23 males aged 14 to 78 years, mean age 49 years) with primary diagnosis of gastric lymphosarcoma (GL). Of them, 56 (89%) patients had diffuse large B-cell lymphosarcoma (DLBCL) and 7 (11%) had gastric Berkitt's lymphoma (BL). Only detection of t(8;14) with rearrangement of c-myc gene provided accurate diagnosis of gastric BL. By the treatment DLBCL patients were divided into two groups: 44 patients of group 1 received polychemotherapy (PCT) according to CHOP scheme or in combination with radiotherapy and surgical treatment; 12 patients of group 2 were treated according to modified program mNHL-BFM-90, without surgical or radiation treatment. Of 7 patients with gastric BL 5 patients received treatment according to a modified program mNHL-BFM-90 and 2 patients were given CHOP because of DLBCL misdiagnosis without cytogenetic detection of t(8;14). RESULTS: Overall survival in group 1 was 73% in mean follow-up 61 months. The survival depended only on initial factors of poor prognosis (PPF): tumor size over 10 cm, Ann-Arbor stage higher than IE, B-symptoms, elevated level of LDH. Overall survival of 18 gastric DLBCL patients without PPF reached 94%, of 26 patients with PPF - 60%. Lethality due to side effects was 4% (2 patients), primary resistance was 14% (6 patients), recurrence arose in 9% (4 patients). Overall survival in group 2 was 100% in mean remission duration 18 months, was unrelated to PPF (10 of 12 patients) but correlated with high toxicity. 5 BL patients treated with a modified mNHL-BFM-90 program achieved remission (a mean follow-up at present is 1 to 50 months, mean 24 months). 2 BL patients treated with CHOP died for a year. CONCLUSION: Gastric lymphosarcomas are sensitive to chemotherapy, thereby PCT only is effective in most patients. PPF in gastric DLBCL were responsible for poor outcome in 40% patients in CHOP treatment. The modified program mNHL-BFM-90 can produce up to 100% complete long-term remissions in therapy of gastric lymphosarcoma in adults both in BL and DLBCL patients. A cytogenetic examination of c-myc gene rearrangement is obligatory before initiation of PCT of gastric lymphosarcoma.

[Efficacy of therapy of different variants of anaplastic large T-cell lymphomas].

AIM: To compare efficacy of NHL-BFM-90 and CHOP-like courses in the treatment of anaplastic large cell lymphoma (ALCL). MATERIAL AND METHODS: Twenty-two patients with ALCL participated in the study. The diagnosis was made basing on the findings of clinical, device, morphological, immunohistochemical and molecular-genetic examinations with application of a panel of monoclonal antibodies to CD30, ALK, CD3, CD4, CDS, CD7, CD34, CD15, CD68, CD20, CD45RO, CD45RA, Ki-67. 14 cases of 22 were negative by kinase of anaplastic lymphocytes (ALK-) and 8 were positive (ALK+). Mean age of ALK-ALCL patients was 39.6 +/- 4.1 years, of ALK+ALCL patients - 23.4 +/- 2.6 years. 14 patients were treated by the protocol NHL-BFM-90, 8 were initially treated with other schemes (CHOP, MACOP-B, BEACOPP and others). All 14 patients treated according to NHL-BFM-90 had ALCL stages III-IV with B-symptoms. 12 patients who completed treatment by the above protocol achieved complete remission after the forth course, 2 patients failed the treatment. Of 8 ALCL patients treated initially according to other schemes, a complete remission was achieved in 4 patients (2 had stage II). One of 4 patients with remission had recurrence. Four patients who had failed to achieve complete remission died of the disease progression. CONCLUSION: ALCL occurs more frequently in young and middle-aged patients. The disease has an aggressive course with rapid generalization. For such processes it is more preferable to use a modified protocol NHL-BFM-90.

[Acute porphyrias: problem of primary diagnosis in Russia and CIS countries].

AIM: To analyse manifestations and experience in primary screening diagnosis of acute porphyrias which are rarely encountered and little known by general practitioners. MATERIAL AND METHODS: The data on 100 patients with the diagnosis acute porphyria have been analysed. Porphyrin metabolism in differential diagnosis was estimated according to standard techniques. RESULTS: Analysis of primary diagnosis of acute porphyria hepatica in Russia (region-related prevalence, duration of diagnosis, complications because of late pathogenetic treatment) demonstrates the importance of screening diagnosis of acute porphyria at the level of municipal clinics. CONCLUSION: Early diagnosis prevents severe complications of acute porphyria and reduces cost of examinations in search of accurate diagnosis.