Multiple statistical analysis techniques corroborate intratumor heterogeneity in imaging mass spectrometry datasets of myxofibrosarcoma

MALDI mass spectrometry can generate profiles that contain hundreds of biomolecular ions directly from tissue. Spatially-correlated analysis, MALDI imaging MS, can simultaneously reveal how each of these biomolecular ions varies in clinical tissue samples. The use of statistical data analysis tools to identify regions containing correlated mass spectrometry profiles is referred to as imaging MS-based molecular histology because of its ability to annotate tissues solely on the basis of the imaging MS data. Several reports have indicated that imaging MS-based molecular histology may be able to complement established histological and histochemical techniques by distinguishing between pathologies with overlapping/identical morphologies and revealing biomolecular intratumor heterogeneity. A data analysis pipeline that identifies regions of imaging MS datasets with correlated mass spectrometry profiles could lead to the development of novel methods for improved diagnosis (differentiating subgroups within distinct histological groups) and annotating the spatio-chemical makeup of tumors. Here it is demonstrated that highlighting the regions within imaging MS datasets whose mass spectrometry profiles were found to be correlated by five independent multivariate methods provides a consistently accurate summary of the spatio-chemical heterogeneity. The corroboration provided by using multiple multivariate methods, efficiently applied in an automated routine, provides assurance that the identified regions are indeed characterized by distinct mass spectrometry profiles, a crucial requirement for its development as a complementary histological tool. When simultaneously applied to imaging MS datasets from multiple patient samples of intermediate-grade myxofibrosarcoma, a heterogeneous soft tissue sarcoma, nodules with mass spectrometry profiles found to be distinct by five different multivariate methods were detected within morphologically identical regions of all patient tissue samples. To aid the further development of imaging MS based molecular histology as a complementary histological tool the Matlab code of the agreement analysis, instructions and a reduced dataset are included as supporting information.

July 2002: 66-year-old female with a one-year history of progressive left proptosis

The July 2002 Case of the Month (COM). This 66-year-old Caucasian female presented with gradually increasing protrusion of her left eye over a one-year period. She complained of increased tearing and foreign body sensation. The physical examination revealed a visual acuity of 20/20, normal color testing, full vision field with motility of her left eye limited in lateral gaze. Pupils were round, symmetric, with no afferent pupillary defect noted. On external examination, her left eye was grossly proptotic with resistance to retropulsion. She had 4 mm proptosis of the left eye. Computed tomography and MR imaging demonstrated a left retro-orbital mass with gadolinium enhancement and focal remodeling of orbital bones. She underwent surgical resection of tumor with a diagnosis of solitary fibrous tumor, and postoperatively she was symptom free. The histopathological differential diagnoses of spindle cell neoplasms of the orbit are discussed. Five months after surgery, no evidence of tumor recurrence was seen on neuroimaging and her vision was 20/20.

Expression of master regulatory genes controlling skeletal development in benign cartilage and bone forming tumors

Recent progress in skeletal molecular biology has led to the clarification of the transcriptional mechanisms of chondroblastic and osteoblastic lineage differentiation. Three master transcription factors-Sox9, Runx2, and Osterix-were shown to play an essential role in determining the skeletal progenitor cells' fate. The present study evaluates the expression of these factors in 4 types of benign bone tumors-chondromyxoid fibroma, chondroblastoma, osteoid osteoma, and osteoblastoma-using immunohistochemistry and tissue microarrays. Osteoid osteoma and osteoblastoma showed strong nuclear expression of Osterix and Runx2. In contrast, only a few chondroblastomas showed positive nuclear expression of Osterix. Strong nuclear expression of Sox9 was detected in all chondroblastomas, whereas nearly half of the osteoblastomas showed focal weak cytoplasmic expression of Sox9.

[Expression of beta-catenin and estrogen receptor in desmoid-type fibromatosis]

OBJECTIVE

To detect the expression of beta-catenin and Estrogen Receptor in desmoid-type fibromatosis.

METHODS

Nuclear beta-catenin expression was detected by immunohistochemistry in 77 lesions with desmoid-type fibromatosis and 171 other spindle cell lesions, including superficial fibromatosis (n = 18), nodular fasciitis (n = 36), keloid (n = 16), scar (n = 10), granulation tissue (n = 9), synovial sarcoma (n = 38), neufibroma (n = 13), solitary fibrous tumor (n =12), gastrointestinal stromal tumor (n = 10), low-grade myxofibrosarcoma (n = 3), low-grade fibromyxoid sarcoma (n = 3), and smooth muscle tumor (n = 10). In addition, the immunohistochemical expressions of ER-alpha, ER-beta and Ki-67 were examined in all of the lesions with desmoid-type fibromatosis. The nuclear immunohistochemical staining for nuclear beta-catenin and ER-beta was graded as high level ( > or = 25% of cells), low level (5%-25%) or none.

RESULTS

High-level nuclear beta-catenin staining was detected in a very limited subset of tissue types, which included 70.1% of lesions with desmoid-type fibromatosis (54/77) and 6.3% of lesions with keloid (1/16). No high-level nuclear beta-catenin staining was seen in any of the other lesions. None of the lesions with desmoid-type fibromatosis expressed ER-alpha. However, 62 (80.5%) of the lesions with desmoids-type fibromatosis were positive in ER-beta, which included 52 (67.5%) with high-level expression, and 10 (13%) with low-level expression. The Spearman correlation analysis suggested that the expression of beta-catenin was positively correlated (r = 0.867, P < 0.05) with the expression of ER-beta. The lesions with desmoid-type fibromatosis had very low Ki-67 positive rate. The recurrence of desmoids-type fibromatosis was not correlated independently with beta-catenin, ER-beta or Ki-67.

CONCLUSION

High-level nuclear beta-catenin staining serves as a useful diagnostic tool for desmoid-type fibromatosis. The high expression of ER-beta in desmoid-type fibromatosis provides a biological mechanism for the antiestrogenic compounds to treat fibromatosis. There might exists an interaction between beta-catenin and ER-beta. Beta-catenin, ER-beta or Ki-67 can not predict the prognosis of desmoid-type fibromatosis.

[Prepubertal-type vulva fibroma: a clinicopathological study of two cases]

OBJECTIVE

To study the clinicopathological features, immnophenotype and differential diagnosis of prepubertal-type vulva fibroma (PVF).

METHOD

Clinical, radiological and pathological features of 2 cases of PVF were analyzed along with a literature review.

RESULTS

Both patients were females of 8.5 and 54 years of age, presented with recurrent unilateral mass at the labium major respectively. Grossly, cut surface of the tumor appeared as the gray fibrous tissue without any definited lump detected. Histologically, the ill-circumscribed lesion located predominantly in the deep dermis with an extension into the subcutaneous tissue. They had a low cell density consisting of scattered spindle shaped fibroblast-like cells and a large amount of collagen fiber matrix, nuclear atypia not seen and mitotic figures scanty. The tumor cells extended downward under the epithelium and infiltrated between the fat tissue, nerve fibers as well as the capillaries making a lesion looked somewhat like a harmatoma. Immunohistochemically, the spindle cells were uniformly positive for vimentin, weakly positive for CD34, and negative for alpha-smooth muscle actin (SMA), muscle specific actin (HHF35), desmin, h-caldesmon, CD99, S-100 protein, bcl-2, beta-catenin, estrogen and progesterone receptors.

CONCLUSIONS

PVF is a benign mesenchymal lesion with a predilection of involving the vulva of prepubertal girls or adults in rare cases. PVF may represent an overgrowth of normal stromal tissue of vulva. Approximately one third of the tumors develop local recurrence due to incomplete excision, however, there is also occasionally spontaneous regression.

[Superficial acral fibromyxoma of finger: report of a case with review of literature]

OBJECTIVE

To study the clinicopathologic characteristics, immunophenotype and differential diagnosis of superficial acral fibromyxoma (SAF).

METHODS

The clinical, pathologic and immunohistochemical features of a case of SAF occurring in left middle finger was studied, with review of literature.

RESULTS

The patient was a 62-year-old male who presented with a solitary painful nodule located in the distal aspect of his left middle finger. The nodule lied close to the nail bed and deep to the underlying periosteum. Grossly, the tumor was poorly circumscribed, measured 2 cm in greatest dimension and had a greyish-white cut surface and rubbery consistency. On low-power examination, the tumor was centred in the dermis and displayed a vague lobular pattern. The tumor cells were spindled to stellate in shape and associated with myxoid matrix. Focal fascicular or loose storiform patterns were also noted. A delicate vascular network was identified in the myxoid stroma. Mast cells were readily observed. On high-power examination, the tumor cells were relatively bland-looking and showed at most a mild degree of nuclear atypia. Mitotic figures were rare and coagulative tumor necrosis was absent. Immunohistochemical study showed that the tumor cells were positive for vimentin, CD34 and CD99. Focal staining for CD10 was also demonstrated. Other immunomarkers including actins, desmin and epithelial membrane antigen were negative.

CONCLUSIONS

SAF is a distinctive soft tissue tumor occurring mainly in the digits of adults. Awareness of this entity is helpful in distinguishing SAF from other myxoid soft tissue tumors occurring there. Complete excision with clear resection margins is the mainstay of treatment.

[Changes of 3-tesla 31P-MR spectroscopy of bone and soft tissue tumors]

OBJECTIVE

To study the characteristic changes of 31P-MR spectroscopy of bone and soft tissue tumors.

METHODS

41 patients were examined by phosphorus surface coil of 3 tesla MR machine, including 18 benign tumor foci and 28 malignant foci, and adjacent normal muscles. The areas under the peaks of various metabolites in the spectra were measured, including phosphomonoester (PME), inorganic phosphours (Pi), phosphodiester (PDE), phosphocreatine (Pcr), adenosine triphosphate (ATP) gamma, alpha, beta. The ratios of the metabolites to beta-ATP, NTP and Pcr were calculated. Intracellular pH was calculated according to the chemical shift change of Pi relative to Pcr.

RESULTS

The ratios of Pcr/PME and PME/NTP in benign and malignant tumor groups were significantly different from those of the normal group (P<0.05). Between benign and malignant tumor groups, the ratios of PME/beta-ATP and PME/NTP were significantly different (P<0.05).

CONCLUSION

Pcr/PME and PME/NTP are potential diagnostic indexes of bone and soft tissue tumors. PME/beta-ATP and PME/NTP are potential indexes of differential diagnosis of bone and soft tissue tumors.

So-called hybrid central odontogenic fibroma/central giant cell lesion of the jaws. A report on seven additional cases, including an example in a patient with cherubism, and hypotheses on the pathogenesis

BACKGROUND

Central odontogenic fibroma (COF) is characterized by poor to cellular fibroblastic proliferation and a variable odontogenic epithelial (OE) component. Central giant cell lesions (CGCL) are osteolytic fibroblastic proliferations characterized by osteoclast-like multinucleated giant cells (MGC). Rare examples of hybrid COF/CGCL have been described. Two pathogenetic theories prevail based on clinicopathologic characteristics. One regards the CGCL component as reactive to the COF, while the other regards the CGCL as inductive of a COF-like proliferation. The possibility of colliding tumors seems unlikely.

METHODS AND MATERIALS

Seven patients with hCOF/CGCL, among them one with cherubism, were studied. Immunohistochemistry for cytokeratin 19 was applied to better appreciate the epithelial component.

RESULTS

Six patients were males and one female and their age ranged from 15 to 73 years old. All lesions occurred in the premolars and molars of the mandible and presented as radiolucencies with primarily well-delineated borders. All patients underwent surgical excision and recurrences have not been reported to this date in 6 out of 7 patients (mean follow-up 60.6+/-36.25 months). The COF component predominated in 3 cases and the CGCL component in 3. Zones of collagen fibers featuring a whorling pattern and containing multiple nests of OE were present. In four cases there were hyalinized deposits in OE, while some foci of MGC contained few OE.

CONCLUSIONS

Gender predilection in our series is in contrast with previously published reports. However, when all previously reported cases are reviewed there is still female predilection. The predominant site, as previously reported, is the tooth-bearing areas of the posterior mandible. This is the first report of hCOF/CGCL in cherubism. The pathogenesis of hCOF/CGCG remains obscure and molecular interactions would be of interest to be investigated.

Fibromatosis of the head and neck: morphological, immunohistochemical and clinical features

The term fibromatosis indicates a proliferation of well-differentiated fibroblasts and myofibroblasts that develops in the soft tissue. This tumor has been considered locally aggressive because of the infiltrative growth pattern, but does not metastasize. Its occurrence in the head and neck region is not common, and very sporadically it may occur in the oral cavity or jaw bones. Two cases of adult fibromatosis are described here; one involving the submucosa of the middle hard palate and the other the subcutaneous area of the frontal bone. Tumor growth was rapid and bone involvement occurred in one case. Biopsies were taken and in both cases histological examination showed a tumor consisting of fibroblasts within a collagenous stroma, with rare atypia and mitoses. The patients underwent surgical resection with wide surgical margins; excised material was analyzed microscopically and a diagnosis of fibromatosis was rendered. Immunohistochemistry was positive for actin, vimentin and desmin, and negative for S-100, CD34, the progesterone receptors (PR)-A and PR-B and the estrogen receptors (ER)alpha and ERbeta. Follow-up at 5 years after surgery found both patients to be progression free. The clinical, histological and immunohistochemical features were analyzed to better characterize this form of the disease, that very rarely involves the oral cavity.

Superficial acral fibromyxoma of the toe, with erosion of the distal phalanx. A clinical report

Superficial acral fibromyxoma (SAFM) is a rare soft tissue tumor most often located in the ungual region of the fingers and toes. This tumor was first described in 2001, and since then very few cases have been reported. We present the case of a 35-year-old male with a SAFM located in the toe, with involvement of the nail and erosion of the distal phalanx. The lesion was surgically removed, and the histopathological study confirmed the diagnosis of SAFM. The differential diagnosis must be established with other myxoid tumors and with those lesions showing a predilection for the distal portions of the limbs. After 2 years, the patient remains disease free, with no disability of any kind.

Lipofibromatosis presenting as a neck mass in eight-years old boy--a case report

Lipofibromatosis is a very rare pediatric neoplasm with a histologically distinctive fibrofatty pattern. Some of the authors believe that this term should encompass several rare soft tissue tumors of childhood and that tumors of childhood which contain fat as an integral component warrant new classification. We present a case report of a neck tumor in eight-years old boy which shares clinical and morphological features similar to those originally described by Fetch et al. with peaceable with literature results of immunohistochemical stains.

The role of noncartilage-specific molecules in differentiation of cartilaginous tumors: lessons from chondroblastoma and chondromyxoid fibroma

BACKGROUND

Chondroblastoma (CB) and chondromyxoid fibroma (CMF) are benign tumors of bone morphologically recapitulating cartilage differentiation. CMF can resemble high-grade central chondrosarcoma (HGCCS) because of its cellular atypia. The mechanism that drives this morphologic spectrum of cartilage differentiation is unclear.

METHODS

CMFs and CBs were hybridized on a complementary DNA microarray that was enriched for cartilage-specific genes. Data were analyzed by Linear Model for Microarray Analysis and were compared with previous data on osteochondromas and HGCCS. Verification was performed in an extended series.

RESULTS

None of the 68 genes that were differentially expressed in CB versus CMF, including several extracellular matrix (ECM) and ECM-degradation genes, were related specifically to cartilage. Perlecan, versican, collagen 4A2 (Col4A2), and cell-cell adhesion genes, such as CD166, were significantly higher in CMF. Sixty genes were expressed differentially in CMF versus HGCCS. Higher expression levels of CD166, cyclin D1 (CCND1), and p16INK4A were observed in CMF.

CONCLUSIONS

The current findings indicated that differential expression of adhesion and ECM molecules, such as CD166, versican, perlecan, and Col4A2, may interfere with cartilaginous differentiation. The decreased expression of CCND1, p16INK4A, and CD166 in HGCCS reflects impairment of cell cycle progression and of cell-cell adhesions in malignant tumors and is of use in the differential diagnosis of CMF.