Pulmonary epithelial-myoepithelial carcinoma: a clinicopathologic and immunohistochemical study of 5 cases

Pulmonary epithelial-myoepithelial carcinomas are rare low-grade malignant neoplasms with histologic features similar to their salivary gland counterparts. We report a series of 5 cases and describe their clinical, morphological, and immunohistochemical features. The patients included 3 men and 2 women whose ages ranged from 38 to 56 years. All patients had obstructing endobronchial lesions that ranged from 2.5 to 5.0 cm in greatest dimension. The tumors were completely resected by simple lobectomy or pneumonectomy. In one patient, the tumor infiltrated perinodal soft tissue of a peribronchial lymph node with intranodal extension and metastasis within the same lymph node. The follow-up in these patients ranged from 4 to 12 months. The histologic appearance of these tumors varied, but all shared the common feature of a biphasic proliferation of epithelial (strong cytokeratin-positive; actin and S-100-negative) and myoepithelial (strong actin and S-100 and focal weak cytokeratin-positive) cells with formation of bilayered ductlike structures. The focal resemblance to other salivary gland-type tumors may cause diagnostic difficulties, particularly in small endobronchial biopsies. Although little is known about their biologic potential due to limited follow-up data, these tumors when in the lung clearly have the capacity to infiltrate and metastasize and therefore should be designated as epithelial-myoepithelial carcinoma. At present, it appears that treatment by complete surgical resection with negative margins alone is appropriate and adequate.     

Pulmonary artery sarcoma: a clinicopathologic and immunohistochemical study of 12 cases

We report 12 cases of pulmonary artery sarcoma. The mean age at diagnosis was 48.4 years. Based on histomorphologic features and immunohistochemical findings, 2 tumors were classified as rhabdomyosarcoma, 4 as leiomyosarcoma, 1 as osteogenic sarcoma, 1 as angiosarcoma, and 4 as high-grade sarcoma. All patients underwent surgery. In addition, 7 patients received neoadjuvant or adjuvant therapy. Five patients died 3 to 23 months after surgery. Three patients were still alive at 8, 27, and 68 months at last follow-up. Another 3 patients were alive at 2, 15, and 40 months and then lost to follow-up. The 2 patients with the longest survival (40 months and 68 months) had a diagnosis of leiomyosarcoma. Both patients with rhabdomyosarcoma died at 3 months after surgery. Pulmonary artery sarcoma is an uncommon entity with a poor prognosis. The role of early diagnosis, histologic classification, surgical treatment, and adjuvant therapy in patient outcome is discussed.     

Pulmonary artery trunk sarcoma: a clinicopathologic, ultrastructural, and immunohistochemical study of four cases

Pulmonary artery sarcomas are rare tumors that arise in the region of the bulbus cordis, the embryologic structure that gives rise to the pulmonary trunk. Nearly 100 cases have been reported in the literature, yet considerable debate exists regarding the histogenesis and biologic properties of these neoplasms. We report four additional cases in which ultrastructural and immunohistochemical studies demonstrated that these tumors contain cellular constituents with features of myofibroblastic, cartilaginous, and osteogenic differentiation. Polyphenotypic expression of several mesenchymal lineages suggests that the progenitor cell has pluripotential properties. Our findings and a review of the literature appear to confirm that pulmonary artery sarcomas are histopathologically heterogeneous, possibly reflecting the indeterminate character of the mesenchymal cell(s) of origin. The poor prognosis is attributable to the critical anatomic location of the neoplasm rather than its metastatic potential, which is low.     

Sialoblastoma: a clinicopathologic and immunohistochemical study of 7 cases

Sialoblastoma is a rare congenital or perinatal salivary tumor that varies in histologic features and biologic potential. Seven cases from the files of the Armed Forces Institute of Pathology are presented. These tumors occurred in 4 males and 3 females with ages ranging from prenatal to 6 months at the time of discovery. Five lesions originated from the parotid gland; 2 lesions were from the submandibular gland. All lesions presented as nodular to multinodular swellings and ranged in size from 2.0 to 7.0 cm. The principal sign or symptom was rapid growth. Two histologic patterns with differing behavior predominated: (1) a favorable pattern had semiencapsulation of cytologically benign basaloid tumor cells with intervening stroma; and (2) an unfavorable histology of anaplastic basaloid tumor cells, minimal stroma, and broad pushing to infiltrative periphery. Four and three tumors had favorable and unfavorable growth patterns, respectively. One unfavorable lesion had vascular invasion, and another demonstrated perineural invasion. All 3 tumors with unfavorable histology recurred. Tumor cells in 3 cases were immunohistochemically reactive for keratin, S-100, smooth muscle actin, and calponin to varying degrees. All 3 tumors were reactive for p63. alpha-Fetoprotein was expressed in 2 unfavorable tumors. Ki67 was expressed at 3% in a favorable tumor and 40% and 80% in the 2 unfavorable lesions. Treatment involved surgical excision. One patient received adjuvant chemotherapy. Two sialoblastomas resulted in recurrences within a year and another developed a recurrence after 4 years. One sialoblastoma developed lung metastasis within 1 month of the original biopsy. Although a clinical correlation is suggested by a favorable/unfavorable histologic grading system the biologic behavior is nonetheless considered unpredictable.     

Primary liposarcoma of the orbit: a clinicopathologic study of seven cases

Liposarcoma, the most common soft tissue sarcoma in adults, will rarely involve the orbit, either primarily or as a metastasis. We describe seven primary orbital liposarcomas, representing the largest documented series of primary orbital liposarcoma to date. Affected patients were three males and four females ranging in age from 28 to 69 years (median, 51 years). Five patients presented with painless proptosis, one patient had painful proptosis, and no details of presenting symptoms are available in one case. The site distribution was retrobulbar (3 cases), lateral orbital wall (2 cases), medial wall (1 case), and unspecified (1 case). Radiologic impression included hemangioma, lipoma, and an inflammatory process. Lesional size ranged from 2.8 to 4 cm. Five liposarcomas were purely well-differentiated, one was dedifferentiated, and one was pleomorphic in type. The well-differentiated cases comprised the following subtypes: spindle cell (2 cases), adipocytic (2 cases), and combined adipocytic/sclerosing/inflammatory (1 case). Five patients underwent orbital exenteration (one followed by radiation) and two had marginal/partial excision of their tumors. Follow-up was available for five patients, ranging from 13 to 204 months (median 65 months). Four patients showed no evidence of recurrence, including the patient with pleomorphic liposarcoma who had a long, disease-free survival (65 months) following marginal excision. One patient has had multiple recurrences following initial partial excision. One patient died of an unrelated cause with no clinical evidence of recurrence. Despite the difficulty in obtaining wide surgical margins, the small tumor size at presentation and the apparent predominance of the well-differentiated type means that the prognosis for orbital liposarcoma is generally good. In view of the various morphologic patterns that may occur, liposarcoma should be considered in the differential diagnosis of any histologically unusual mesenchymal lesion in the orbit.     

Sinonasal teratocarcinosarcoma: a clinicopathologic and immunohistochemical study of 6 cases

Teratocarcinosarcoma (TCS) is a rare and unusual malignant neoplasm of the sinonasal tract with a heterogenous morphology and an aggressive behavior. Patients are predominantly adults with a male predominance. The aim of this study was to describe clinicopathologic and immunohistochemical features of 6 cases of TCS. The ages ranged from 18 to 67 years (mean, 33 years) with a male-to-female ratio of 5:1. Most tumors were located in the nasal cavity. Nasal obstruction and epistaxis were the common presenting symptoms. Histologically, all tumors exhibited a heterogeneous morphology with varying proportions of benign and malignant epithelial, mesenchymal, and neuroepithelial elements. Adenocarcinoma was the malignant epithelial component in all cases. The mesenchymal elements were composed of benign to malignant spindle cells. Osteosarcomatous areas were seen in 2 cases and rhabdomyosarcoma in 1 case. Rhabdoid differentiation was also seen in 1 case. Immunohistochemical stains CKAE1/AE3 and CK Cam 5.2 were positive in the epithelial elements, vimentin in mesenchymal, and CD56 and neuron-specific enolase in neuroepithelial elements. Follow-up was available in 4 patients and ranged from 21 to 40 months (mean, 31 months). Lung and dura metastasis, respectively, were seen in 1 patient each. However, all 4 patients are alive and free of disease to date. In conclusion, TCS is a rare but highly malignant tumor with aggressive behavior characterized by benign and malignant epithelial, mesenchymal, and neuroepithelial components. Two patients in our series were younger than 20 years. The occurrence of rhabdoid differentiation and osteosarcomatous component seen in our series were rarely described in literature. Recognition of all the components requires adequate sampling, which is crucial for a correct diagnosis.     

Cutaneous myoepithelioma: a clinicopathologic and immunohistochemical study of 14 cases

Analogous to mixed tumors of salivary glands (" pleomorphic adenomas" ), cutaneous mixed tumors (" chondroid syringomas" ) contain a ductal (epithelial) component and a variably prominent myoepithelial component. Tumors showing purely myoepithelial differentiation (myoepitheliomas) have only recently been recognized to arise in the dermis, and to date very few cases have been described. To characterize these tumors further, 14 cutaneous myoepithelial tumors were retrieved from the authors' consult files. Eleven patients were male and 3 were female; their median age was 22.5 years (range, 10 to 63 years), and 7 patients were between 10 and 20 years old. Tumor size ranged from 0.5 to 2.5 cm (mean, 1.1 cm). Most tumors arose on the extremities: 6 on the upper limbs, 6 on the lower limbs, and 1 each on the back and nose. Ten tumors were limited to the dermis, and 5 also extended into superficial subcutis. Thirteen tumors were myoepitheliomas (lacking ductal differentiation), and 1 tumor was a myoepithelial carcinoma (exhibiting severe cytological atypia and a high mitotic rate). Histologically, 7 tumors were solid, composed of ovoid to spindled, histiocytoid, or epithelioid cells with no significant stroma, and 7 were predominantly lobulated, with cords or nests of epithelioid, plasmacytoid, or spindled cells with a variably reticular architecture and a chondromyxoid or collagenous/hyalinized stroma. One tumor was composed solely of plasmacytoid (hyaline) cells, and 1 exhibited extensive adipocytic differentiation. Among the 13 myoepitheliomas, mitoses ranged from 0 to 6 per 10 high-power fields (HPFs) (mean, 1.5); 8 tumors contained no mitoses. The myoepithelial carcinoma had 39 mitoses per 10 HPFs. By immunohistochemistry, all cases were reactive for epithelial markers (keratins and/or epithelial membrane antigen [EMA]); 13 of 14 (93%) expressed S-100 protein, 10 of 11 expressed (91%) calponin, 11 of 14 (79%) expressed EMA, 9 of 14 (64%) expressed keratins, 8 of 14 (57%) expressed smooth muscle actin, 7 of 14 (50%) expressed glial fibrillary acidic protein, 3 of 11 (27%) expressed p63, and 1 of 6 (17%) expressed desmin. All 5 cases without keratin staining were diffusely positive for EMA, and all of these cases showed a solid growth pattern. Follow-up was available for 8 patients (median follow-up, 40 months; range, 6 months to 9 years); 3 tumors (38%) recurred locally, and 1 tumor (13%) also metastasized to the lymph nodes. The case that resulted in recurrence and metastasis had the highest mitotic rate (6 per 10 HPFs) of the cytologically benign tumors. Follow-up information was not available for the myoepithelial carcinoma. This study suggests that approximately 50% of cutaneous myoepitheliomas are distinctive lesions composed of a solid proliferation of cells with abundant eosinophilic syncytial cytoplasm, which often lack immunostaining for keratin, whereas the remainder demonstrate focally reticular architecture and myxoid stroma or plasmacytoid cells, similar to their counterparts in salivary gland and soft tissue. Whereas most cutaneous myoepitheliomas behave in a benign fashion, there is apparently a significant risk for local recurrence but a low metastatic potential.     

Pulmonary endodermal tumor resembling fetal lung: a clinicopathologic study of five cases with immunohistochemical and ultrastructural characterization

Pulmonary endodermal tumor resembling fetal lung describes an uncommon neoplasm of the lung which also has been referred to as pulmonary blastoma and adenocarcinoma of fetal lung type. We describe five cases which fall within a narrow band on the spectrum of pulmonary neoplasms with both epithelial and mesenchymal features. These five cases all occurred as well-defined masses visible on chest radiograph in middle-aged females, and were treated by surgical excision. Histopathologically, low and high grades of malignancy are found. Well-formed racimose glands with cytoplasmic vacuolization resemble endometrioid carcinoma. Neoplastic columnar cells have abundant glycogen in the cytoplasm. Morules of cells within the glands have optically clear nuclei. Ultrastructurally, the optically clear nuclei are occupied by a filamentous substructure of chromatin. Multiple neuroendocrine hormones are present in low-grade malignancy. Nuclear pleomorphism, lymphatic invasion, multifocal necrosis, lack of mesenchyme at the pulmonary interface, and restricted neuroendocrine expression suggest high-grade malignancy. A mesenchymal stroma surrounding the glands is an intrinsic part of the neoplasm, but the stroma does not appear malignant, and did not form part of the metastasis in the single case where a metastasis occurred. Stromal cells show fibroblastic and myofibroblastic differentiation. Pulmonary endodermal tumor resembling fetal lung typically is a low-grade malignancy, with a better prognosis than the majority of lesions sometimes described as pulmonary blastoma or adenocarcinoma of fetal lung type.     

23例原发性十二指肠癌临床病理与免疫组化分析

应用免疫组化方法和临床病理资料对２３例十二指肠癌加以分析，结果表明，原发性十二指肠癌患者发病高峰期为５０～６０岁，肿瘤发生在乳头部最多见（１５例，占６５％），在组织分型上，以管状腺癌（１２例）和乳头状腺癌（７例）多见。免疫组化染色显示，１１例病人伴有神经内分泌细胞分化，其中伴有胰多肽表达者９例，胃泌素８例，生长抑素４例，胰高血糖素３例，两种激素同时表达者４例，三种激素表达者４例，单一激素表达者３例     

上皮样肉瘤样血管内皮瘤的临床病理学观察

目的 探讨上皮样肉瘤样血管内皮瘤的临床病理学特征和鉴别诊断.方法 回顾性分析3例上皮样肉瘤样血管内皮瘤的临床表现、组织学特点和免疫表型.结果 3例均发生于成年男性,分别因左颈部肿块、髂部疼痛和双侧颈肩区复发性肿块就诊.镜下观察肿瘤由梭形和上皮样的细胞组成,两种细胞在形态上有移行.瘤细胞呈片状、模糊结节状或交织条束状排列,间质伴有胶原化.1例于结节中央可见凝固性坏死,形态上类似上皮样肉瘤.3例肿瘤内均无明显的血管形成,但其中1例于局灶区域可见胞质内空泡形成,类似上皮样血管内皮瘤.免疫组织化学标记,瘤细胞同时表达上皮性标记和内皮标记.3例均经手术切除,其中2例患者术后恢复良好,随访18个月和14个月均健在,无局部复发或远处转移,另1例术后6年内复发5次.结论上皮样肉瘤样血管内皮瘤属于一种少见的中间型血管内皮瘤,兼具上皮样肉瘤和上皮样血管内皮瘤的部分形态.仅凭光镜形态有时较难确定其内皮细胞分化,必须借助于免疫组织化学标记.上皮样肉瘤样血管内皮瘤与上皮样血管内皮瘤关系较为密切,可能是后者的一种富于细胞性梭形细胞变型.

Abstract：

Objective To study the clinicopathologic features and differential diagnosis of epithelioid sarcoma-like hemangioendothelioma (ES-H). Methods The clinical, radiologic and pathologic features of three cases of ES-H were analyzed. Results All the 3 cases occurred in male adults. The age ranged from 44 to 53 years. The presentations included left neck mass, iliac pain and bilateral shoulder masses. Histologically, ES-H was composed of a mixture of spindle and epithelioid tumor cells. Transition between the two cell types was demonstrated. The tumor cells were arranged in compact sheets, vague nodules or intersecting fascicles, amongst a collagenous stroma. Central coagulative necrosis was identified in one case, reminiscent the morphology that seen in epithelioid sarcoma. There was no evidence of angiogenesis, though focal presence of intracytoplasmic vacuoles was seen in one case, as in classic examples of epithelioid hemangioendothelioma. Immunohistochemical study showed that the tumor cells expressed both epithelial (AE1/AE3, CAM5.2 and epithelial membrane antigen) and endothelial (CD31,Fli-1 and factor Ⅷ-related antigen ) markers. Two of the cases were also positive for CD34. All of the patients were treated by surgical resection. Two patients remain well at 14-month and 9-month follow up,respectively. The remaining patient had repeated local recurrences during a 6-year period. Conclusions ES-H represents a rare morphologic type of hemangioendothelioma. It has some overlapping histologic features with epithelioid sarcoma and epithelioid hemangioendothelioma. The endothelial nature of ES-H is difficult to be verified on the basis of morphologic examination alone. Confirmation of the diagnosis with immunohistochemistry is necessary. ES-H is likely related to epithelioid hemangioendothelioma and may represent a cellular spindie cell variant of epithelioid hemangioendothelioma.     

Primary oral and maxillofacial liposarcoma: a clinicopathological and immunohistochemical study of eleven cases

Introduction

The present study was aimed to characterize the clinicopathological, immunohistochemical features and treatment outcomes of primary oral and maxillofacial liposarcomas by presenting the experience over a 16-year period at a tertiary referral Chinese institution for head neck cancer.

Material and methods

This retrospective clinical study included 11 cases of pathologically confirmed primary liposarcomas treated from January 1993 to September 2009. Detailed information regarding primary site, clinical manifestations, histopathological and immunohistochemical analysis, treatments and prognosis was collected and reported.

Results

Eight female and 3 male patients aged from 8 to 76 years old. These lesions occurred in buccal (3), parotid (2), temporal (2), tongue (2), palate (1) and oropharyngeal (1) region. They were histopathologically categorized into 4 subtypes based on WHO classification scheme: atypical lipomatous tumor/well-differentiated (4), myxoid (4), mixed-type (2) and pleomorphic (1) liposarcomas. Immunohistochemical staining indicated mostly positive for Vimentin and S-100 but negative for other markers. Most patients presented as slow-growing painless masses and underwent surgery alone or combined with postoperative radiotherapy. Two patients were misdiagnosed and inappropriate treated and developed local relapse before referred to our institute. No distant metastasis and one disease-related death were recorded during the follow-up (ranging: 1-11 years, mean: 4.5 years).

Conclusions

Oral and maxillofacial liposarcoma is exceedingly rare and has atypical clinical manifestations but characteristic histopathology. Complete excision with negative margins followed by long-term follow-up is recommended as the treatment of choice for these uncommon entities.     

Pleomorphic liposarcoma: a clinicopathologic analysis of 19 cases.

Pleomorphic liposarcoma is a variant of liposarcoma defined morphologically by the presence of pleomorphic lipoblasts. Because of its rarity, there are limited studies with long-term follow-up information. Nineteen pleomorphic liposarcomas were studied. Unequivocal pleomorphic lipoblasts were required for inclusion. In each case, the following features were noted: tumor site; tumor size; tumor depth; predominant histologic pattern (epithelioid or malignant fibrous histiocytoma [MFH]-like); extent of necrosis (absent, less than 15%, or at least 15%); mitotic counts; treatment and clinical follow-up. Patients were 11 females and 8 males, aged 33-87 years (mean, 64.5 y; median, 70 y). Tumors involved the extremities (13 patients: intramuscular in 10, subcutaneous in 2, depth unknown in 1), retroperitoneum (4 patients), mediastinum (1 patient), and paratesticular region (1 patient). Size ranged from 4.5--31 cm (mean, 11.9 cm; median, 12.0 cm). Predominant pattern was epithelioid in 7 and MFH-like in 12. Necrosis was present in 15 (79%) and was extensive (36 15%) in 14 patients. Mitotic counts ranged from 0.2--3.4/10 high-power fields (mean, 1.4; median, 1.4) by the average-count method and from 1--6/10 high power fields by the highest count method (mean, 2.9; median, 3.0). All patients were treated surgically; 10 patients received adjuvant chemotherapy and/or radiation therapy. On follow-up of 18 patients (range, 2--129 mo; mean, 35.4 mo; median, 23 mo) nine (50%) were dead of disease (range, 2--48 mo; mean, 20.1 mo; median, 12 mo), one died of other causes 2 months after diagnosis, two were alive with disease, five were disease free, and one was alive at 129 months (tumor status unknown). Five had recurrences (range, 3--28 mo; mean, 14.4 mo; median, 8 mo), and four of five (80%) with recurrences were dead of disease. Metastases developed in eight patients (range, 4--48 mo; mean, 19.5 mo; median, 11.5 mo), most commonly to the lungs. In conclusion, pleomorphic liposarcoma is a rare tumor of adulthood that occurs most commonly in the deep, soft tissues of the extremities. It behaves as a high-grade sarcoma that frequently metastasizes, most commonly to the lungs. Although this tumor has a wide range of histologic appearances, no clinical or pathologic feature is predictive of a more aggressive clinical course.     

Elastofibroma: a clinicopathologic and immunohistochemical study of seven cases and literature review

Elastofibroma is a rare fibrous lesion characterized by accumulated abnormal elastic fibers whose etiology remains largely unknown. In this study, we analyzed seven cases of elastofibroma to further explore the characteristics of its cellular composition. Immunohistochemistry was performed for mast cell tryptase, S-100 protein, vimentin, CD34, smooth muscle actin, desmin and collagen type IV. Histochemical staining methods for Gomori's trichrome and Verhoeff elastica-van Gieson were also evaluated. Histopathologically, a haphazard array of collagen, eosinophilic amorphous fibers, and globules in a fibrous tissue was seen. The elastic nature of the fibers was confirmed by elastic stain, and with Gomori's trichrome collagen fibers were also demonstrated. The interspersed spindle or stellate cells were almost consistently positive for vimentin and frequently positive for CD34. Mast cell tryptase-positive cells were present in five of the cases. Collagen type IV immunoreactivity was seen in two cases. No staining was observed with smooth muscle actin, desmin or S-100 protein. Our findings suggest that CD34-positive mesenchymal cells are an integral component of elastofibroma.     

Thymic carcinoma, part 1: a clinicopathologic and immunohistochemical study of 65 cases

The clinicopathologic and immunohistochemical features of 65 primary thymic carcinomas are reported (43 men and 22 women; 19-81 years old). Thymectomy was performed in all cases. Masaoka staging for 53 patients showed 3 patients in stage I, 14 in stage II, 17 in stage III, and 19 in stage IV. Histologic studies revealed 9 carcinoma subtypes. Immunohistochemically, the tumors showed high rates of expression for cytokeratin, Pax8, and FoxN1. Follow-up for 62 patients revealed that 36 patients were alive (mean follow-up, 51.1 months) and 26 had died (mean survival, 47.5 months). The 3- and 5-year overall survival rates were 76.6% and 65.7%, respectively. Our findings suggest that thymic carcinomas may behave less aggressively than commonly believed. Lymph node status and tumor size seem to be important prognostic factors. The Masaoka staging system does not seem to reliably predict outcome.     

Extrapleural solitary fibrous tumor: a clinicopathologic study of 24 cases.

Solitary fibrous tumors (SFTs), rare in extrapleural sites, can present difficulties in diagnosis at these locations. From the files of the M. D. Anderson Cancer Center, we accessed 24 cases of extrapleural SFT (14 females, 10 males, ages 19 to 85 yr) obtained for clinical, histologic, immunohistochemical, and follow-up findings. Tumor locations included the head and neck (n = 12), the abdomen (n = 10), and the extremities (n = 2). Tumors were 2 to 25 cm in greatest dimension (mean, 8.2 cm) and were well circumscribed or encapsulated. Histologic features were typical of their pleural counterparts, e.g., bland spindle cells with some hypercellular areas and myxoid to hyalinized backgrounds. A hemangiopericytic vascular pattern was present in 19 cases and prominent in 11. Mitotic activity ranged from 0 to 4 counts per 10 high-power fields. Necrosis was seen in two cases. Focally increased cellularity was seen in seven cases and margins were positive in another seven cases. Spindle cells were positive for vimentin (19 of 19) and CD34 (18 of 20), and negative for cytokeratin (0 of 19). Fibroblastic differentiation was present in the three cases studied by electron microscopy. Flow cytometry in three cases revealed diploid cell populations. Follow-up for 19 cases (9 to 99 mo) revealed no evidence of metastasis, although one patient had residual tumor after an incomplete excision, and one patient died of unrelated causes. Histologic findings such as mitotic counts, necrosis, cellularity, and marginal status were not associated with outcome. We conclude that extrapleural SFTs are clinically and histologically similar to their pleural counterparts. Although the length of clinical follow-up was short (mean follow-up, 41.4 mo), recognizing these lesions is important because they typically follow an indolent clinical course if completely excised. Although CD34 is nonspecific, it is usually positive in SFTs and may aid in their diagnosis.