Improving palm oil quality through identification and mapping of the lipase gene causing oil deterioration.

The oil palm fruit mesocarp contains high lipase activity that increases free fatty acids and necessitates post-harvest inactivation by heat treatment of fruit bunches. Even before heat treatment the mesocarp lipase activity causes consequential oil losses and requires costly measures to limit free fatty acids quantities. Here we demonstrate that elite low-lipase lines yield oil with substantially less free fatty acids than standard genotypes, allowing more flexibility for post-harvest fruit processing and extended ripening for increased yields. We identify the lipase and its gene cosegregates with the low-/high-lipase trait, providing breeders a marker to rapidly identify potent elite genitors and introgress the trait into major cultivars. Overall, economic gains brought by wide adoption of this material could represent up to one billion dollars per year. Expected benefits concern all planters but are likely to be highest for African smallholders who would be more able to produce oil that meets international quality standards.

Ewing-like adamantinoma.

The Ewing-like variation of adamantinoma is a rare entity, leading to challenge its differential diagnosis, notably with Ewing's sarcoma. We are reporting a case of a 20-year-old male who presented with swelling in the left leg that had progressed over a 2-year period. X-rays revealed a tumour in the tibia that was intracortical, osteolytic, multilocular and invaded the soft tissues. A surgical biopsy was performed. Histopathology examination showed a tumour growth with small round cells expressing CD99. A diagnosis of Ewing's sarcoma was made. Since the patient declined surgical treatment, chemotherapy was administered. Two years later, the patient returned because the tumour had grown in size. A second biopsy was performed. Microscopic evaluation showed a tumour growth with osteofibrous and epithelial components, which expressed pankeratin and vimentin, but was negative for CD99. A diagnosis of Ewing-like adamantinoma was made.

Identification of a putative triacylglycerol lipase from papaya latex by functional proteomics.

Latex from Caricaceae has been known since 1925 to contain strong lipase activity. However, attempts to purify and identify the enzyme were not successful, mainly because of the lack of solubility of the enzyme. Here, we describe the characterization of lipase activity of the latex of Vasconcellea heilbornii and the identification of a putative homologous lipase from Carica papaya. Triacylglycerol lipase activity was enriched 74-fold from crude latex of Vasconcellea heilbornii to a specific activity (SA) of 57 µmol·min(-1)·mg(-1) on long-chain triacylglycerol (olive oil). The extract was also active on trioctanoin (SA = 655 µmol·min(-1)·mg(-1) ), tributyrin (SA = 1107 µmol·min(-1)·mg(-1) ) and phosphatidylcholine (SA = 923 µmol·min(-1)·mg(-1) ). The optimum pH ranged from 8.0 to 9.0. The protein content of the insoluble fraction of latex was analyzed by electrophoresis followed by mass spectrometry, and 28 different proteins were identified. The protein fraction was incubated with the lipase inhibitor [(14) C]tetrahydrolipstatin, and a 45 kDa protein radiolabeled by the inhibitor was identified as being a putative lipase. A C. papaya cDNA encoding a 55 kDa protein was further cloned, and its deduced sequence had 83.7% similarity with peptides from the 45 kDa protein, with a coverage of 25.6%. The protein encoded by this cDNA had 35% sequence identity and 51% similarity to castor bean acid lipase, suggesting that it is the lipase responsible for the important lipolytic activities detected in papaya latex.

Endometrial stromal sarcoma presenting as a cystic abdominal mass.

Endometrial stromal sarcoma (ESS) is rarely localized in extrauterine sites if metastasis or local extension of the primary uterine tumour are excluded, and diagnosis can be delayed because of the unusual site. We report a case of abdominal ESS in a 45-year-old woman who presented with an abdominal complaint. Ultrasound of the abdomen showed a large multiloculated cystic mass. The complete excision of the tumour revealed ESS arising in endometriosis. The tumour expressed hormonal receptors and the patient was administered hormonal therapy. ESS has a better prognosis than the sarcoma that is part of differential diagnosis, and is associated with endometriosis in about one-half of cases.

Desmoplastic spitz nevus: report of a case and review of the literature.

Desmoplastic spitz nevus (DSN) is an uncommon melanocytic lesion. The histologic features of this benign tumour may mimic those of certain benign (dermatofibroma and desmoplastic cellular blue nevus) or malignant (metastatic carcinoma and malignant melanoma) neoplasms. We report the case of a male with a DSN, and also review the clinical characteristics, histologic features and differential diagnosis of this extremely rare lesion. The lesion is identified as an asymptomatic reddish-brown dome-shaped papule on the forearm. Microscopic examination showed a symmetric lesion in the dermis. The neoplastic cells were large and epithelioid-shaped, and were either isolated as individual cells or arranged in small nests in a paucicellular hyalinized stroma. Nuclei were large and vesicular with small nucleoli and no mitoses. Diffuse expression of S100 and the absence of staining with antibodies to melan-A and HMB45 was observed. A diagnosis of DSN with free margins was made. The histologic presentation of this benign lesion mimics both benign and malignant neoplasms. The immunohistochemical profile (S100 positive, HMB-45 negative and cytokeratin negative) may be helpful to differentiate it from other lesions.

Smooth muscle differentiation in ovarian granulosa-cell tumours: a new case report.

Smooth muscle differentiation in stromal ovarian tissue has rarely been described in normal and tumoural ovaries, especially in granulosa-cell tumours. A moderately differentiated adult granulosa-cell tumour in an 83-year-old-woman is reported. Tumoural stroma included clusters of regular smooth muscle cells stained positively for smooth muscle actin. The presence of smooth muscle differentiation in an ovarian granulosa-cell tumour should be taken into consideration during diagnosis.

[An unusual renal neoplasm: mucinous tubular and spindle cell carcinoma]. / Une tumeur rénale à connaître: le carcinome tubulomucineux et fusiforme.

Mucinous tubular and spindle cell carcinoma is a rare and newly described type of renal cell carcinoma (RCC) with a relatively indolent behaviour. We report a case of 53-year-old woman who had macroscopic hematuria and flank pain. A right radical nephrectomy was performed showing a well circumscribed tumour confined to the kidney and measuring 17cm. The histologic findings consisted of tightly packed, small, elongated tubules separated by pale mucinous stroma. The tumour cells were cuboidal to spindled with eosinophilic cytoplasm and lower nuclear grade. Tumour was immunoreactive for cytokeratin CK 7, CK19 and epithelial membrane antigen (EMA). The morphological and immunohistochemical features were consistent with mucinous tubular and spindle cell carcinoma of kidney.

[Sclerosing epithelioid fibrosarcoma. A case report]. / A propos d'un cas de fibrosarcome épithélioïde sclérosant.

Sclerosing epithelioid fibrosarcoma is a rare variant of fibrosarcomas, which was recently identified as a separate entity due to specific histologic and immunohistochemistry features and its poor prognosis. We report a case of sclerosing epithelioid fibrosarcoma of soft tissues, which developed in a 37-year-old woman who presented a tumor involving the posteromedial aspect of the left knee and which progressed in size for one year. Imaging revealed a well-delimited tumor process measuring 8 cm in its largest diameter and situated in the medial compartment of the left knee. Histology of the tumorectomy specimen and the immunohistochemistry study led to the diagnosis of sclerosing epithelioid fibrosarcoma of soft tissues. This new case illustrates the characteristic features of this tumor and recalls the difficult pathological diagnosis.

Lipolytic enzymes in Mycobacterium tuberculosis.

Mycobacterium tuberculosis is a bacterial pathogen that can persist for decades in an infected patient without causing a disease. In vivo, the tubercle bacillus present in the lungs store triacylglycerols in inclusion bodies. The same process can be observed in vitro when the bacteria infect adipose tissues. Indeed, before entering in the dormant state, bacteria accumulate lipids originating from the host cell membrane degradation and from de novo synthesis. During the reactivation phase, these lipids are hydrolysed and the infection process occurs. The degradation of both extra and intracellular lipids can be directly related to the presence of lipolytic enzymes in mycobacteria, which have been ignored during a long period particularly due to the difficulties to obtain a high expression level of these enzymes in M. tuberculosis. The completion of the M. tuberculosis genome offered new opportunity to this kind of study. The aim of this review is to focus on the recent results obtained in the field of mycobacterium lipolytic enzymes and although no experimental proof has been shown in vivo, it is tempting to speculate that these enzymes could be involved in the virulence and pathogenicity processes.

[Orbital metastasis of liposarcoma]. / Métastase orbitaire d'un liposarcome.

INTRODUCTION: Liposarcoma, the most common soft tissue sarcoma in adults, rarely involves the orbit. Primary orbital liposarcomas are extremely rare, with less than 30 cases previously reported. Metastatic orbital liposarcomas are also extremely rare, with only a few cases documented in the literature. We report a new case of an orbital metastatic liposarcoma and review the literature. OBSERVATION: A 57-year-old man with a history 5 years before of myxoid liposarcoma on the right calf, completely surgically resected, was admitted for recent proptosis of the left eye. A computed tomographic scan revealed a heterogeneously enhancing, left orbital mass measuring 30x23x20 mm. The mass adhered to the internal medial muscle without extension to the optic nerve. A biopsy was taken, which showed typical aspects of myxoid liposarcoma. The patient underwent an orbital left exenteration after first refusing any proposed treatment. CONCLUSION: Liposarcoma metastatic to the orbit is exceptional. It should be suspected in a patient with exophthalmia caused by a space-occupying lesion and a history of liposarcoma.

Paraganglioma: report of a rare case with ovarian involvement.

We report a well-documented case of paraganglioma involving right ovary, which was initially misdiagnosed as a Sertoli-Leydig cell tumor and recurred one year later. The right ovarian tumor measured 105x90x60 mm and was associated to a subdiaphragmatic tumor measuring 80x60x35 mm, a peritoneal and a preureteral nodules measuring 10 mm either. Microscopically, tumor cells were arranged in trabeculae and cords separated by a delicate stroma. Their cytoplasm was abundant granular and eosinophilic. Their nuclei were enlarged and regular in size with coarse chromatine and a large nucleolus. The tumor expressed neuroendocrine markers (chromogranin, synaptophysin) epithelial membrane antigen and focally cytokeratin 7 and E-cadherin. Pathological ovarian paraganglioma diagnosis could be difficult but one should be aware of its bona fide existence. The clinical course is favourable in most of the cases.

Breast metastases from undifferentiated nasopharyngeal carcinoma.

The most common primary tumours metastasising to the breast include melanoma, lymphoma, lung cancer and ovarian cancer, while metastases from head and neck cancer are rare. Metastases from undifferentiated nasopharyngeal carcinoma cancers are extremely rare, and only 3 well-documented cases have been reported in the English literature. We report a fourth case of breast metastases from nasopharyngeal carcinoma confirmed by in situ hybridization, focusing on clinical data as well as radiologic and pathologic features.

Small cell malignant melanoma: an unusual morphologic variant.

Small cell melanoma is a recognized rare variant of malignant melanoma. We report a case of a brown, ulcerated papule on the left third finger of an 80-year-old woman. Microscopic examination revealed the presence within the epidermis of diffuse sheets of monomorphic small to medium-sized cells. The nuclei were round or oval, and hyperchromatic with inconspicuous nucleoli. Melanin pigment was either absent or minimal. This case report draws attention to the difficulties encountered in the histological diagnosis of this rare variant of malignant melanoma.

Assaying lipase activity from oil palm fruit (Elaeis guineensis Jacq.) mesocarp.

The mesocarp of mature oil palm fruit undergoes intensive triglycerides hydrolysis upon abscission and bruising. This generates such a high amount of free fatty acids that the oil might become unfit for human consumption without appropriate refining. The lipase (EC 3.1.1.3) involved in the breakdown of the oil is not stable after homogenization of the tissue in aqueous buffers. In this study, we have devised a solvent-based procedure that allowed us to obtain fractions with stable lipase activity. Using these fractions, we have determined the optimal conditions for assaying mesocarp lipase activity. The activity was highest at a temperature of 35 degrees C and a pH of 9. The lipase was found to be strictly calcium dependent. The specific activity of the lipase measured in optimal conditions was found to be 33 mumol fatty acids released min(-1) mg(-1) protein using olive oil as substrate. The mesocarp contains about 190 U of lipase g(-1) fresh weight. This activity was found to be inhibited by the lipase inhibitor tetrahydrolipstatin (THL), suggesting that the lipase is a serine hydrolase.

Myxoid tumor of soft tissue.

Focal myxoid change is a well-recognised feature of synovial sarcoma, but the presence of a predominantly myxoid stroma is rare. We describe a new case of myxoid synovial sarcoma in which marked myxoid change initially obscured the diagnosis leading to confusion with malignant peripheral nerve sheath tumor. The patient was a 16 year old man who presented with a left dorsal foot tumor. The diagnosis of synovial sarcoma was suspected on histological and immunohistochemical studies and confirmed with cytogenetic analysis. Recognition of this rare histologic variant of synovial sarcoma is important because it can easily be mistaken for other myxoid spindle cell neoplasms, potentially resulting in suboptimal therapy.

[Conjunctival dirofilariasis due to Dirofilaria Repens. A new Tunisian case]. / Dirofilariose conjonctivale à Dirofilaria repens. A propos d'un nouveau cas tunisien.

INTRODUCTION: Dirofilariasis due to Dirofilaria repens is a parasitic disease affecting domestic animals and transmitted to man by mosquito bites. Human infestation is rare and involves benign subcutaneous and ocular manifestations. The diagnosis is made by excisional biopsy, which is also the sole recommended treatment. There are few reports of human infection in Tunisia. CASE REPORT: We report herein the second case of conjunctival dirofilariasis in a 21-year-old woman residing in Tunis (Tunisia). The clinical presentation evoked orbital cellulites. Clinical and radiological investigations did not provide a diagnosis. Surgical excision and histological examination established the diagnosis by the presence of an adult female worm identified as Dirofilaria repens. Parasite extraction allowed successful treatment. CONCLUSION: Dirofilariasis is rare in Tunisia, with only seven cases reported. The true incidence of dirofilariasis is probably greater than recognized. This can be explained by the apparent benign nature of the lesions that may not warrant excision.

[Deep benign fibrous histiocytoma: a case report]. / L'histiocytofibrome bénin profond: à propos d'un cas.

Bening fibrous histiocytoma is one of the most frequent benign tumors. Most tumors are found in the skin, particularly on the limbs. Tumor size is usually small. According to the WHO, a deep location is found for less than 1% of all benign fibrous histiocytomas. Most deep tumors occur in the subcutaneous tissue. Deep locations in other organs have also been reported. We report a case and discuss the pathological and clinical aspects of this rare tumor.

[Soft tissue epithelioid hemangioendothelioma: a case report]. / Hémangio-endothéliome épithélioïde des tissus mous. A propos d'un cas.

We report a case of epithelioid hemangioendothelioma observed in soft tissue in a 35-year-old man who presented a painful mass of the right arm which progressed in size for two years. Imaging revealed a 7-cm poorly limited expansive tumor process located in the medial muscle compartment of the right arm. Surgical resection was performed. Histological and immunohistochemical examination led to the diagnosis of soft tissue epithelioid hemangioendothelioma. The tumor recurred in the right arm and the right axillary fossa with development of multiple nodules in the contralateral thoracic wall and pleural effusion. Adjuvant chemotherapy and radiotherapy were performed, but the patient died at two years.

Micropapillary transitional cell carcinoma of the urinary bladder: report of two cases.

Micropapillary carcinoma is an uncommon variant of urothelial carcinoma with apparent high metastatic potential. The reported cases in the literature were associated with high grade and stage of disease at presentation and a poor prognosis. Micropapillary carcinoma is considered a tumor with an aggressive behavior, even though the morphology may be deceptive. The presence of a micropapillary carcinoma component in bladder biopsies should alert the urologists to the potential of higher stage disease and deep biopsies should be obtained. Two cases of micropapillary carcinoma of the urinary bladder were presented. A 71-year-old woman and a 68-year-old man presented with urinary symptoms. Cystoscopy revealed a papillary tumor on the bladder wall in both cases. Pathologic examination of transurethral resection specimen showed an invasive micropapillary carcinoma; small solid nests lying in small clear spaces that were not stained with antibody CD34. Thus, the lacunar histological pattern did not appear to represent invasion of vascular spaces. Only one case showed an association with urothelial carcinoma. No case showed muscle invasion. No recurrence or metastasis were observed after the initial diagnosis in the two cases.