Mapping rRNA 2'-O-methylations and identification of C/D snoRNAs in Arabidopsis thaliana plants

In all eukaryotic cells, the most abundant modification of ribosomal RNA (rRNA) is methylation at the ribose moiety (2ʹ-O-methylation). Ribose methylation at specific rRNA sites is guided by small nucleolar RNAs (snoRNAs) of C/D-box type (C/D snoRNA) and achieved by the methyltransferase Fibrillarin (FIB). Here we used the Illumina-based RiboMethSeq approach for mapping rRNA 2ʹ-O-methylation sites in A. thaliana Col-0 (WT) plants. This analysis detected novel C/D snoRNA-guided rRNA 2ʹ-O-methylation positions and also some orphan sites without a matching C/D snoRNA. Furthermore, immunoprecipitation of Arabidopsis FIB2 identified and demonstrated expression of C/D snoRNAs corresponding to majority of mapped rRNA sites. On the other hand, we show that disruption of Arabidopsis Nucleolin 1 gene (NUC1), encoding a major nucleolar protein, decreases 2ʹ-O-methylation at specific rRNA sites suggesting functional/structural interconnections of 2ʹ-O-methylation with nucleolus organization and plant development. Finally, based on our findings and existent database sets, we introduce a new nomenclature system for C/D snoRNA in Arabidopsis plants.

Effect of Agave americana L. on the human, and Aspergillus oryzae S2 α-amylase inhibitions

Among phenolic compounds, Agave americana L. extract contained puerarin (38.4%) and p-coumaric acid (12.29%) (pCa). From the Lineweaver-Burk plots, pCa and puerarin demonstrated a competitive and a non competitive inhibitions towards human α-amylase activity, respectively. PCa exhibited a higher human inhibitory activity with an IC₅₀ of 98.8 μM which was about 2.3 times than acarbose. Puerarin (IC₅₀ = 3.87 μM) and pCa (IC₅₀ = 10.16 μM) also showed an excellent inhibition for Aspergillus oryzae S2 α-amylase activity. The inhibitions of the described biocatalysts compounds towards both amylases were significantly decreased when they were pre-incubated with starch. The binding modes of these compounds were evaluated in silico. The binding efficiency order of these molecules in terms of polar contact numbers for both enzymes was in agreement with the in vitro studies. These findings provided a rational reason to establish the isolated compounds capability as therapeutic target for hyperglycaemia modulation and antifungal therapy.

Microcystic transitional cell carcinoma: a rare tumor of the urinary bladder

Microcystic urothelial carcinoma is a rare variant of invasive transitional cell carcinoma recognized by the WHO classification. It is characterized by its deceptively benign appearance. The clinical course of this uncommon variety of carcinoma is not well known and their histological and immunohistological features are not well defined. We report a case of a 37-year-old man with a microcystic transitional cell carcinoma of the urinary bladder. He was diagnosed 4 years ago with cystitis glandularis lesions and nephrogenic adenoma. Through this observation we will try to define the clinical and pathological features of this uncommon tumor which must be differentiated from a number of proliferative lesions of the urothelium. The poor prognosis and aggressiveness of this tumor seems to be related to a higher stage and grade at diagnosis.

Relevant genetic polymorphisms and kidney expression of Toll-like receptor (TLR)-5 and TLR-9 in lupus nephritis

Toll-like receptor (TLR) genetic polymorphisms may modify their expression causing inflammatory disorders and influencing both susceptibility and severity of lupus erythematosus. We aim to determine whether TLR-5 and TLR-9 gene polymorphisms are implicated in the susceptibility to systemic lupus erythematosus (SLE) and lupus nephritis (LN) and to evaluate their expressions and distributions in renal LN patients' biopsies. The frequencies of two SNP in the TLR-9 gene and one in the TLR-5 gene was examined in 106 SLE patients (among them 37 LN patients) and in 200 matched controls by polymerase chain reaction-restriction fragment-length polymorphisms (PCR-RFLP) analysis. TLR-9 and TLR-5 expressions were assessed by reverse transcription (RT)-PCR and immunohistochemistry carried on LN renal biopsies compared to healthy renal tissue. A significant genotypic and allelic association was revealed between TLR-9-rs352140 and both SLE and LN (P < 0·05). The TLR-9 transcript level was significantly higher in LN biopsies compared to control (P < 0·05). This increase was observed histochemically in the tubulointerstitial compartment. TLR-9 was detectable in LN glomeruli patients but not in normal control glomeruli. No allelic nor genotype association was found with TLR-5-rs5744168 in SLE. but the T allele and the TT genotype were raised significantly in the LN group (P < 0·05). A significant increase in TLR-5 gene expression in LN biopsies, which contrasted with normal kidneys (P < 0·05), was confirmed by an intense and diffuse staining for TLR-5 only in LN tubules (P < 0·05). Our data show that TLR-5 and TLR-9 are susceptible genes to LN and that their expression is dysregulated in LN patients' kidneys, supporting a role of these mediators in the pathogenesis of LN.

Telangiectatic osteosarcoma of the rib: a rare entity and a potential diagnostic pitfall

Osteosarcoma (OS) is a common primary malignant tumor of bones that produces osteoid matrix. Telangiectatic osteosarcoma (TOS) is a rare variant of OS. It affects the long bones especially the lower end of femur and the upper ends of tibia and humerus, a distribution similar to the conventional osteosarcoma. The rib involvement is very infrequent. We present a case of TOS of the rib that posed a diagnostic difficulty owing to its unusual location and to its resemblance to giant cell tumor and aneurysmal bone cyst. Correspondence.

Aspergillus Oryzae S2 α-Amylase Domain C Involvement in Activity and Specificity: In Vivo Proteolysis, Molecular and Docking Studies

We previously reported that Aspergillus oryzae strain S2 had produced two α-amylase isoforms named AmyA and AmyB. The apparent molecular masses revealed by SDS-PAGE were 50 and 42 kDa, respectively. Yet AmyB has a higher catalytic efficiency. Based on a monitoring study of the α-amylase production in both the presence and absence of different protease inhibitors, a chymotrypsin proteolysis process was detected in vivo generating AmyB. A. oryzae S2 α-amylase gene was amplified, cloned and sequenced. The sequence analysis revealed nine exons, eight introns and an encoding open reading frame of 1500 bp corresponding to AmyA isoform. The amino-acid sequence analysis revealed aY371 potential chymotrypsin cleaving site, likely to be the AmyB C-Terminal end and two other potential sites at Y359, and F379. A zymogram with a high acrylamide concentration was used. It highlighted two other closed apparent molecular mass α-amylases termed AmyB1 and AmyB2 reaching40 kDa and 43 kDa. These isoforms could be possibly generated fromY359, and F379secondary cut, respectively. The molecular modeling study showed that AmyB preserved the (β/α)8 barrel domain and the domain B but lacked the C-terminal domain C. The contact map analysis and the docking studies strongly suggested a higher activity and substrate binding affinity for AmyB than AmyA which was previously experimentally exhibited. This could be explained by the easy catalytic cleft accessibility.

An unusual tumour of the lung

We report a case of a 51-year-old woman with a solitary mast cell tumour of the lung, a rare neoplasm with only three previously-reported cases reported in the literature. Unlike previous cases, the tumour in the present case was bulky, measuring 14 cm in diameter and budding into the segmental bronchus. Histologically, it showed proliferation of typical metachromatic mast cells intermingled with undifferentiated cells with a ratio of 3:1. The neoplastic mast cells stained strongly with tryptase, CD117, CD68 and CD45, CD14 and CD33; whereas the undifferentiated cells lacked all these markers and expressed EMA and cytokeratin. Histological examination of bone marrow and laboratory data were unremarkable. To our knowledge, this is the fourth case of solitary extracutaneous mastocytoma of the lung. The differentiating features of this neoplasm and a review of literature are presented.

[Pseudotumor phenotype of sarcoidosis: about two cases]

INTRODUCTION

Sarcoidosis is a multisystem benign granulomatous disease of unknown etiology. It can sometimes cause diagnostic confusion by presenting in the form of a pseudotumor, thus constituting a trap for the unwary.

COMMENTS

The authors report two cases of pseudotumor sarcoidosis. In the first, the pseudotumor occurred in the context of multisystem disease in a 48-year-old man. The response to treatment with systemic corticosteroids was complicated by the development of disseminated tuberculosis, which was rapidly fatal. The second case, by contrast, was about a 58-year-old woman and the disease was self-limiting, resolving spontaneously in less than 3 months.

CONCLUSION

Through these two cases, the authors focus on the particularities of the pseudotumor manifestation of pulmonary sarcoidosis. The diagnosis is often difficult. The mismatch between the clinical picture and the extent of radiological lesions should, however, suggest the diagnosis. Histological evidence is needed to eliminate other etiologies including malignant tumors. The condition usually resolves either spontaneously or after treatment with systemic corticosteroids. However, relapses are possible, including on discontinuation of corticosteroid therapy.

[Mediastinal mature teratoma with spontaneous malignant transformation]

INTRODUCTION

Malignant teratomas can be either immature teratomas or they can develop after treatment of other malignant germ cell tumors with chemotherapy or radiotherapy. Spontaneous malignant transformation of mature teratomas is very rare.

OBSERVATION

We report the case of a patient complaining of atypical chest pain. Chest plain radiography showed a right anterior mediastinal mass. Computed tomography revealed a heterogeneous mediastinal mass with fat areas and calcification. There were hilar and mediastinal lymph nodes as well as lung parenchymal nodules. CT-guided and then surgical biopsies confirmed the diagnosis of a mature teratoma, which had degenerated into a digestive adenocarcinoma.

CONCLUSION

Spontaneous malignant transformation of mature mediastinal teratoma is very rare. The diagnosis of malignant transformation is based on radiological examinations, laboratory tests and histological studies.

A novel dominant mutation in SIX1, affecting a highly conserved residue, result in only auditory defects in humans

Branchio-oto-renal (BOR) and Branchio-otic (BO) syndromes are dominant disorders characterized by variable hearing impairment (HI) and branchial defects. BOR includes additional kidney malformations. BO/BOR syndromes are genetically heterogeneous and caused by mutations in EYA1 and SIX1 genes. Mutation in SIX1 is responsible also for DFNA23, a locus for non-syndromic HI. Strikingly, the severity of the phenotype did not seem to correlate with the type of SIX1 mutation. Herein, we identified a novel mutation in SIX1 (p.E125K) in a Tunisian family with variable HI and preauricular pits. This mutation is located at the same position as the mutation identified in the Catwhesel (Cwe) mouse. No renal and branchial defects were observed in our family nor in Cwe/+ mice. A homology model revealed that the replacement of the Glutamate by a Lysine alters the electrostatic potential surface propriety which may affect the DNA-binding activity.

Reinforcement of a minor alternative splicing event in MYO7A due to a missense mutation results in a mild form of retinopathy and deafness

PURPOSE

Recessive mutations of the myosin VIIA (MYO7A) gene are reported to be responsible for both a deaf-blindness syndrome (Usher type 1B [USH1B] and atypical Usher syndrome) and nonsyndromic hearing loss (HL; Deafness, Neurosensory, Autosomal Recessive 2 [DFNB2]). The existence of DFNB2 is controversial, and often there is no relationship between the type and location of the MYO7A mutations corresponding to the USH1B and DFNB2 phenotype. We investigated the molecular determinant of a mild form of retinopathy in association with a subtle splicing modulation of MYO7A mRNA.

METHODS

Affected members underwent detailed audiologic and ocular characterization. DNA samples from family members were genotyped with polymorphic microsatellite markers. Sequencing of MYO7A was performed. Endogenous lymphoid RNA analysis and a splicing minigene assay were used to study the effect of the c.1935G>A mutation.

RESULTS

Funduscopy showed mild retinitis pigmentosa in adults with HL. Microsatellite analysis showed linkage to markers in the region on chromosome 11q13.5. Sequencing of MYO7A revealed a mutation in the last nucleotide of exon 16 (c.1935G>A), which corresponds to a substitution of a methionine to an isoleucine residue at amino acid 645 of the myosin VIIA. However, structural prediction of the molecular model of myosin VIIA shows that this amino acid replacement induces only minor structural changes in the immediate environment of the mutation and thus does not alter the overall native structure. We found that, although predominantly included in mature mRNA, exon 16 is in fact alternatively spliced in control cells and that the mutation at the very last position is associated with a switch toward a predominant exclusion of that exon. This observation was further supported using a splicing minigene transfection assay; the c.1935G>A mutation was found to trigger a partial impairment of the adjacent donor splice site, suggesting that the unique change at the last position of the exon is responsible for the enhanced exon exclusion in this family.

CONCLUSIONS

This study shows how an exonic mutation that weakens the 5' splice site enhances a minor alternative splicing without abolishing a complete exclusion of the exon and therefore causes a less severe retinitis pigmentosa than the USH1B-associated alleles. It would be interesting to examine a possible correlation between intrafamilial phenotypic variability and the subtle variation in exon 16 inclusion, probably related to genetic background specificities.

[Appendicular cystadenocarcinoma with cutaneous fistula]

BACKGROUND

Cutaneous metastasis of colorectal cancer is rare. We report a case of fistular lesions of the buttocks revealing a mixed tumour of the appendix involving mucinous cystadenocarcinoma and carcinoid tumour.

CASE REPORT

A 67-year-old woman was admitted for four skin fistulae of the right buttock present for 6 years. Histological examination of skin biopsy specimens identified infiltration of the dermis by metastatic mucinous adenocarcinoma while colonoscopy showed a caecal tumour measuring 4 cm. Surgical excision was performed involving right hemicolectomy, evacuation of retroperitoneal mucin collection and excision of fistulae. Histopathological examination of surgical specimen confirmed mixed tumour consisting of perforated mucinous cystadenocarcinoma and carcinoid tumour of the appendix. Recurrence of the fistular lesions was seen. The patient was hospitalized several times for surgical drainage of mucin. She died one year later.

DISCUSSION

Cutaneous metastasis of colorectal cancer is an uncommon event that usually occurs after identification of the primary tumour and generally indicates advanced-stage disease and an ominous prognosis. This case is particular and underlines the need to rule out a metastatic origin of cutaneous fistulae, even in patients otherwise apparently in good health.

[Extrafollicular adenomatoid odontogenic tumour: report of two cases]

The purpose of this study was to analysis the clinicopathological features of adenomatoid odontogenic tumour extrafollicular and to discuss the diagnosis pitfull. We present two cases diagnosed and followed at the C.H.U. Habib Bourguiba, Sfax. It is about a 15 year-old boy and a 46 year-old woman who presented gingival swelling. The panoramic radiographs showed in both cases, a radiolucent area affecting teeth 23, 24 and 35 respectively. A computed tomography scan, realized at the second cas, demonstrated an expansile lesion with a sclerotic rim. An exploratory surgical approach was chosen and the final diagnosis was microscopically confirmed to be an extrafollicular variant of adenomatoid odontogenic tumour. The patients were healthy and have not shown any signs of recurrence at follow-up. The two cases described illustrate clinical and radiographic features of the extrafollicular variant of adenomatoid odontogenic tumour. Careful diagnostic procedure and adequate interpretation of radiographic findings may result in a correct diagnosis with otherwise may result in unnecessary endodontic treatment.

[A rare localization of solitary plasmocytoma]

INTRODUCTION

Solitary bone plasmocytoma is rare, characterized by malignant plasmocyte proliferation, derived from a sole B lymphocyte clone located on a bony segment without medullar invasion. It, above all, affects the thoracolumbar spine. Costal involvement is rarely described.

CASE REPORT

The authors report the case of a 60-year-old man who complained of dyspnea, dry cough, and thoracic pain four months before admission. Thoracic imaging revealed a left apical tissue mass with osteolysis of the first rib. A transparietal biopsy of the mass was not helpful. Surgical biopsy concluded as to the diagnosis of costal plasmocytoma. All of the examinations carried out to search for other localizations were negative confirming the solitary nature of the tumor. The treatment consisted of complementary radiotherapy at a dose of 45Gy. The patient was in remission after eight months.

CONCLUSION

Solitary costal plasmocytoma should be called to mind when confronted with a lytic tumor of the rib. The treatment is based on surgery and radiotherapy. The prognosis is dominated by the risk of progression to multiple myeloma.

Small cell osteosarcoma: a case report

INTRODUCTION

Small cell osteosarcoma (SCO) is a rare bone tumour representing 1.3% of all osteosarcomas. This rare variety of osteosarcoma tends to arise in the metaphysis of long bones and may extend secondary to epiphysis. By histopathology, the tumour is composed of small round cells with a variable degree of osteoid production. We report a new case of SCO in the distal femur with epiphyseal involvement. We also present the clinical, radiologic and therapeutic features of SCO with particular emphasis on the pathologic features that allow differentiation of this neoplasm from other small round cell tumours.

OBSERVATION

A 14-year-old girl presented with a 6-month history of a painful tumefaction of the left knee with motor deficit. Imaging analysis of the knee demonstrated a lytic lesion of the metaphysis in addition to epiphysis of the distal femur with cortical destruction and invasion of soft tissues. Histological examination of a biopsy specimen showed sheets of neoplastic small round cells simulating Ewing's sarcoma. Osteoid was focally present. A diagnosis of SCO was made. The patient received 2 cycles of adjuvant chemotherapy with ifosfamide, adriamycin and cisplatin. MRI showed no change in tumour size. An en bloc, wide-margin resection of the lesion was performed. Histological examination showed a viable tumour with few necrotic foci. The patient received adjuvant chemotherapy with Holoxan and VP16. The clinical response was favourable.

CONCLUSION

SCO is a rare clinical entity with a high grade of malignancy that must be distinguished from other round cell tumours, particularly Ewing's sarcoma, in order to optimise treatment protocols.

[Amelanotic spitzoid melanoma of the digit: case report]

BACKGROUND

Melanomas of digit is rare, accounting for 1% of all cutaneous melanomas. We report a new case.

AIM

Our purpose is to discuss the clinicopathological characteristics and the difficulties encountred in establishing diagnosis of this rare tumor.

OBSERVATION

we report the case of a 25-years-old woman, who consulted for nodular and ulcerated lesion of the right index, located in the external face of the metacarpo-phalangeal joint. The nodule was biopsied and histopathologic exam concluded to spitzoid melanoma. The surgical margins were involved. The patient refused surgical recovery. She consulted 3 years later with axillary lymph nodes. A wide excision of the tumor with lymph node biopsy were made. Histological study concluded to a tumoral residu incompletely excided with lymph node metastases. Amputation of the second digit with dissection of the axillary lymph nodes was made. The surgical margins were tumor free. Lung metastases appeared with a follow up of two months. The patient died early after starting chemotherapy with Deticen.

CONCLUSION

In our report, clinical presentation was misleading causing a diagnosis and therapeutic delay. Pathologically, all the histological types of melanoma were described in the digit except spitzoid melanoma.

[Severe rectal bleeding in an Tunisian woman: colonic tuberculosis mimicking a tumor]

Since colonic tuberculosis is uncommon and its bifocal pseudo-tumor form is exceptional, differential diagnosis with the colonic cancer is exceedingly difficult. The purpose of this report is to describe a case of primary colonic tuberculosis in two separate locations discovered in a patient presenting with persistent massive hematochezia. A 69-year-old woman was examined for hematochezia, abdominal pain and recent weight loss. Colonoscopy revealed the presence of two ulcerated tumor-like lesions in right colon. One of these lesions caused significant stenosis. Histological examination of biopsy specimens was inconclusive. Colonic tumor with bleeding was considered as the most likely diagnosis. Surgical exploration demonstrated one tumor in the cecum and another in the ascending colon. Right hemicolectomy was performed. Histological examination of the surgical specimen demonstrated a granulomatous reaction pattern with caseous necrosis. Conventional antituberculosis treatment led to clinical improvement.

Glomus tumour of uncertain malignant potential

A 71-year-old man presented with a several year story of a slowly enlarging, painful mass of the knee. Surgical findings showed a subcutaneous, well-circumscribed mass fixed to the patella, and a wide resection was performed. Macroscopically, the tumour measured 6 x 5 x 5 cm and was well circumscribed. The tumour was characterised by superficial location, large size and focal marked atypia. In addition, areas of benign glomus tumour (GT) were identified. The findings appear to be consistent with the diagnosis of GT of uncertain malignant potential.

Molecular modelling of the TSR domain of R-spondin 4

R-spondin 4 is a secreted protein mainly associated with embryonic nail development. R-spondins have been recently identified as heparin-binding proteins with high affinity. Proteoglycan binding has been associated with both the TSR and the C terminal basic amino acid rich domains. In this paper, molecular modelling techniques were used to construct the model of R-spondin 4 TSR domain based on the structure of the F-spondin TSR domain 4 (30-40¢ sequence identity). Beside a positively charged surface in the TSR domain, presence of the basic amino acid rich domain which could forms a continuous heparin binding surface may explain the high affinity of R-spondins for heparin. Our results provide a framework for understanding the possible regulatory role of heparin in R-spondins signalling.

Mutations of LRTOMT, a fusion gene with alternative reading frames, cause nonsyndromic deafness in humans

Many proteins necessary for sound transduction have been identified through positional cloning of genes that cause deafness. We report here that mutations of LRTOMT are associated with profound nonsyndromic hearing loss at the DFNB63 locus on human chromosome 11q13.3-q13.4. LRTOMT has two alternative reading frames and encodes two different proteins, LRTOMT1 and LRTOMT2, detected by protein blot analyses. LRTOMT2 is a putative methyltransferase. During evolution, new transcripts can arise through partial or complete coalescence of genes. We provide evidence that in the primate lineage LRTOMT evolved from the fusion of two neighboring ancestral genes, which exist as separate genes (Lrrc51 and Tomt) in rodents.

[Frantz's tumor: anatomoclinical study of six Tunisian cases]

Solid and pseudopapillary tumour (Frantz's tumour) is a rare low-grade neoplasm of the pancreas. We report six new cases. Our objective is to specify clinical and pathological characteristics of this rare neoplasm and to discuss its histogenesis. A retrospective review was considered on six Tunisan patients who had solid and pseudopapillary tumor of the pancreas. A review of medical registries and morphological analysis with immunohistochemical study were carried out in all cases. Four patients were female and two patients were male with a median age of 27,5 years (range: 14 - 68 years). Abdominal pain was the most common initial symptoms (5 cases/6). Abdominal computed tomography and/or ultrasonography was used in all the cases. The tumour was in the tail of the pancreas in 4 patients and in the body of the pancreas in one patient; one tumor involved all the pancreas. The median diameter of the tumour was 16,8 cm (range: 8 - 35 cm). Three tumours had an extrapancreatic extension. All patients underwent surgical resection. No adjuvant therapy was recommended. The mean follow up period was 24 months (range: 5 - 78 months). Only one patient died during the surgery. Except for this patient, none experienced tumor recurrence or tumor-related mortality during the follow up period. Solid and pseudopapillary tumour of the pancreas is an uncommon neoplasm which shows distinct clinicopathologically characteristics. Despite diverse studies, its histogenesis remains undetermined. This tumor should be distinguished from other pancreatic neoplasms because its prognosis is excellent after surgical resection.

Identification of candidate regions for a novel Usher syndrome type II locus

PURPOSE

Chronic diseases affecting the inner ear and the retina cause severe impairments to our communication systems. In more than half of the cases, Usher syndrome (USH) is the origin of these double defects. Patients with USH type II (USH2) have retinitis pigmentosa (RP) that develops during puberty, moderate to severe hearing impairment with downsloping pure-tone audiogram, and normal vestibular function. Four loci and three genes are known for USH2. In this study, we proposed to localize the gene responsible for USH2 in a consanguineous family of Tunisian origin.

METHODS

Affected members underwent detailed ocular and audiologic characterization. One Tunisian family with USH2 and 45 healthy controls unrelated to the family were recruited. Two affected and six unaffected family members attended our study. DNA samples of eight family members were genotyped with polymorphic markers. Two-point and multipoint LOD scores were calculated using Genehunter software v2.1. Sequencing was used to investigate candidate genes.

RESULTS

Haplotype analysis showed no significant linkage to any known USH gene or locus. A genome-wide screen, using microsatellite markers, was performed, allowing the identification of three homozygous regions in chromosomes 2, 4, and 15. We further confirmed and refined these three regions using microsatellite and single-nucleotide polymorphisms. With recessive mode of inheritance, the highest multipoint LOD score of 1.765 was identified for the candidate regions on chromosomes 4 and 15. The chromosome 15 locus is large (55 Mb), underscoring the limited number of meioses in the consanguineous pedigree. Moreover, the linked, homozygous chromosome 15q alleles, unlike those of the chromosome 2 and 4 loci, are infrequent in the local population. Thus, the data strongly suggest that the novel locus for USH2 is likely to reside on 15q.

CONCLUSIONS

Our data provide a basis for the localization and the identification of a novel gene implicated in USH2, most likely localized on 15q.

[Pure colloid carcinoma of the breast: anatomoclinical study of seven cases]

PURPOSE

Breast mucinous carcinoma is a particular histological form characterized by the extracellular production of mucus. The pure form is rarely reported and its prognostic is better than the other types of the breast cancer. The aim of the present study was to discuss the various anatomoclinical, therapeutic aspects and the prognostic factors of the pure mucinous carcinoma of the breast.

PATIENTS AND METHODS

We report seven cases diagnosed over a period of 11 years (1993-2003) in the laboratory of anatomy and pathological cytology of the university hospital of Sfax. A review of the clinical files with immunohistochemistry study (hormonal receptor, synaptophysine, chromogranine, Bcl2, Ki67, P53 and Her-2/neu (C-erbB-2)) were carried out for all the cases.

RESULTS

pure colloid carcinoma of the breast accounted for 0,5% of the whole of the breast cancers. The average age of patients was 69 years. At the time of the diagnosis, four tumours were classified T4, one T3, two T2, two N1 and one N3; no patient had presented metastasis (M0) according to pTNM classification. The echomammography showed regular contours mass in four cases. The anatomopathological study showed that the neuroendocrine differentiation was found in two cases, all the tumours had presented positivity for the hormonal receptors (oestrogen and progesterone) and negativity for the other antibodies, two cases exhibited the Bcl2 positivity and negativity for the other antibodies. An adjuvant radiotherapy was carried out for all the patients. The average duration of follow-up was of 33 months; the evolution was marked by the occurrence of metastases in two cases.

CONCLUSION

The pure colloid carcinoma of the breast constitutes a particular morphological entity which deserves to be individualized; neuroendocrine differentiation of these tumours must be required. Their forecast is relatively favourable.

[Polymorphous low-grade adenocarcinoma: a palatine and a labial location]

INTRODUCTION

Polymorphous low-grade adenocarcinoma (PLGA) is a variant of malignant tumor of minor salivary glands. We had for aim to discuss morphology, evolution and differential diagnosis of this rare tumor.

CASE REPORTS

The first case was a 65-year-old woman admitted for a two-month history of a right submaxillary swelling. The examination revealed a tumor of the right side of the palate. Biopsy was positive for a pleomorphic adenoma. The mass was enlarged and surgical resection was performed. The diagnosis was a partially resected PLGA. The patient also received adjuvant radiotherapy. There was a local recurrence 28 months after complete treatment. The second case was a 57-year-old woman who consulted for a 12-year history of lower lip swelling. The examination revealed a painless 2cm long located nodule in the mucosal side of the lower lip. An excisional biopsy was performed. The pathological examination concluded to a completely resected PLGA. The patient was free of disease at 54 months follow-up.

DISCUSSION

The morphologic diversity and cytological uniformity of PLGA may make the differential diagnostic difficult especially with adenoid cystic carcinoma and pleomorphic adenoma. Its aggressiveness is proved by a local infiltrative growth pattern requiring a large surgical excision.

[Unusual intra-abdominal tumor]

Desmoplastic small round cell tumor is a rare poorly differentiated, aggressive neoplasm that most frequently affects the abdominal cavity. The diagnosis is often difficult requiring morphological and immunohistochemical study. The purpose of our study is to clarify the anatomoclinical aspects of this rare tumor and to discuss the approach of the diagnosis and the prognosis. A 18-year old teenager had presented an enormous intra-abdominal mass. The radiologic findings showed a mass for 20 cm in diameter repulsing the liver and the right kidney. A surgical biopsy was performed. Histopathologic examination demonstrated a proliferation of small round cells surrounded by a desmoplastic stroma. Immunohistochemical staining was positive for pancytokeratin (KL1), epithelial membrane antigen (EMA), vimentin, neuron specific enolase (NSE) and desmine; thus, the diagnosis of a desmoplastic small round cell tumor was made. The patient received a first chemotherapy followed by a maximal surgical reduction. A local recurrence and bone metastasis occurred and the patient eventually died 18 months after the diagnosis from hepatic failure. The diagnosis of desmoplastic small round cell tumor may be suspected in young patient presenting an intra-abdominal small round cell tumor. The treatment is multidisciplinary and its prognosis is poor.

Expression de c-kit dans les carcinomes nasopharyngés nord africains, corrélations avec l'âge et LMP1

PURPOSE

To determine the level and prognostic significance of c-kit expression in the two age groups of North African nasopharyngeal carcinomas.

PATIENTS AND METHODS

A retrospective study of 99 NPC specimens from Tunisian patients was investigated by immunohistochemistry. Immunohistochemical data were correlated with Epstein-Barr virus LMP1 expression and pathological, clinical and survival parameters.

RESULTS

c-kit was detected in 79% of the cases for patients under 30 years of age (juvenile form) but in only 56% of specimens in patients over 30 years (P=0.039) and was significantly over-expressed for patients with lymph node involvement (P=0.015). LMP1 score was 5.78 (+/-1.84) for c-kit negative tumors compared to 8,23 (+/-2.39) for c-kit positive tumors (P=0.002). Multivariate analysis including age, lymph nodes involvement and LMP1 expression as co-variables, showed that only age (P=0.027) and LMP1 expression (P=0.005) were significantly correlated to the c-kit expression.

CONCLUSION

c-kit is highly expressed in the juvenile form of North African nasopharyngeal carcinomas. There is a significant association between LMP1 and c-kit expression. The contrasted levels of C-kit expression in the two age groups strengthen the hypothesis that these clinical forms result from distinct oncogenic mechanisms.

[Pediatric mandibular myofibromatosis]

INTRODUCTION

Pediatric myofibromatosis is a rare tumor in neonates and children. Two forms are described, solitary and multicentric, the solitary type is more common and is localized mainly on the head and the neck, mandible involvement is rare. The aim of this article was to report the anatomoclinical and therapeutic features of this pediatric tumor in a case as well as its follow-up.

CASE REPORT

A 10-year-old girl was brought to consultation for a lower left gingival swelling 5 cm in diameter, forming a unit with the mandibular bone. The volume had gradually increased over the last 12 months. Imagery revealed the presence of an osteolytic tumor benign in aspect, but locally aggressive. Conservative surgery was performed. The diagnosis of pediatric myofibromatosis was confirmed. Evolution was excellent and after three years of follow-up, there was no evidence of relapse.

DISCUSSION

Pediatric myofibromatosis often presents as a painless, well-circumscribed, solid nodule. Imagery is very useful to assess lesion extension and for the therapeutic follow-up. The diagnosis is made on anatomopathological findings and immunohistochemical assessment. The treatment of the solitary myofibromatosis is primarily surgical and its prognosis is excellent contrary to the multicentric form.

[Granulosa-cell tumor of the ovary: report of 16 cases]

OBJECTIVE

The aim of this work was to describe the epidemiological, pathological and clinical features of granulosa cell tumors and to study the different prognostic factors in order to determine an appropriate therapeutic attitude.

PATIENTS AND METHODS

We proceeded with a retrospective study of 16 cases of granulosa cell tumors of the ovary diagnosed over a period of 10 years (1994-2003). These cases included one case of juvenile type and 15 adult types.

RESULTS

Mean patient age was 46 years for the adult type (range 20-70 years) and 35 years for the juvenile type; 19% of the patients were nulliparous, 31% were menopausals. The predominant symptom was abdomino-pelvic pain with frequent hormonal manifestations. Mean tumor size was 10.5 cm with a solido-cystic aspect in 50% of cases. The treatment was surgical in all cases. Among the 16 patients, 14 (87.5%) were diagnosed at stage I and one (6.2%) at stage II. The juvenile tumor was at stage IV at time of diagnosis and only adjuvant chemotherapy was given. No relapse nor recurrence were noted for the adult type after a mean follow up of 2 years 2 months. For the juvenile form, locoregional recurrence with liver metastasis developed after 9 months.

CONCLUSION

Granulosa cell tumor of the ovary is an uncommon neoplasm. The adult form progresses slowly and often is diagnosed in an early stage of disease. Surgery is indicated. The juvenile forms are more exceptional and more aggressive. A prolonged post therapeutic follow-up is necessary because of the risk of recurrences, late and exceptional for the adult form but frequent and early for the juvenile form.

[Mammary hydatid cyst diagnosed by fine needle aspiration]

INTRODUCTION

Echinococcal involvement of the breast is extremely rare and usually not included in the differential diagnosis of breast lumps.

OBSERVATION

This is an unreported case of a 56-year-old woman who came with a 3 cm mammary mass. Mammography showed a dense well-circumscribed lesion with calcifications. The diagnosis was established by fine needle aspiration and confirmed by pathological study.

CONCLUSION

Hydatid cyst of the breast is rare. The diagnosis by fine needle aspiration is controversial. The treatment is based on complete excision of the cyst.