Selective breast/gynecologic pathology fellowship training in the United States: Experience of program directors.

Published data on combined breast and gynecologic [breast/gyn] surgical pathology fellowship training programs are limited. Our study aimed to survey the landscape of such fellowships in the United States (US), including specific information about their characteristics and the educational activities therein. Using web searches, we identified programs offering combined breast/gyn surgical pathology fellowship training. We developed a 26-item questionnaire asking program directors to report on the characteristics of their fellowship training structure. The search revealed 25 academic based programs offering one-year combined breast/gyn fellowship training, predominantly located (40 %) in the Northeast area. The following data was obtained: 44 % of the programs were accredited by the ACGME, 82 % required >19 weeks of breast and gyn service, and 69.6 % accepted the common application, 54.5 % of programs require completion of a research project for graduation. An annual average of 3000 breast and 3000 gyn cases appears to be the usual volume of cases. Interestingly, only 36 % of the program directors are graduates of a combined breast/gyn fellowship program. In conclusion, we present the most comprehensive and up-to-date census of combined breast/gyn pathology fellowships in the US. Our study provides valuable information on the current state of combined breast/gyn pathology fellowship training. The information will be helpful to current and prospective trainees, as well as program leaders.

Collision Tumor of the Ovary Involving Sertoli-Leydig Cell Tumor and High-Grade Serous Carcinoma-Report of the First Case.

We report a collision tumor in the ovary of a 60-yr-old woman composed of high-grade serous carcinoma and Sertoli-Leydig cell tumor. Collision tumors in the ovary are rare and to the best of our knowledge, combination of ovarian high-grade serous carcinoma and Sertoli-Leydig cell tumor has not been described before.

Do Skin Lacerations Imply Tissue Transfer From Surgeon to Patient During Arthroscopic Knot Tying?

PURPOSE: To use simulated arthroscopic knot tying to assess (1) whether epithelial cells from the surgeon's hands were transmitted to the suture and (2) whether the number of knots tied or the presence of glove tears would correlate with the number of cells transmitted. METHODS: Knots were tied in a simulated arthroscopic environment using a nonabsorbable No. 2 suture over a metal hook. The surgeon was double gloved for each knot tied. For each "anchor," a surgeon's knot was tied, followed by 3 reversed half-hitches on alternating posts. Multiple skin lacerations were sustained by the surgeon during each knot-tying session. Gloves were collected after tying 2, 4, or 6 anchors. Gloves were tested for perforation by (1) electroconductivity and (2) saline solution load testing. Cytopathologic ThinPrep analysis was applied and allowed for the number of epithelial cells found on each suture (within 10 high-powered fields) to be counted. Statistical analysis included analysis of variance and logistic regression. RESULTS: There was no significant difference in the number of epithelial cells identified in any of the groups compared with the negative control groups (P > .05) or with each other (P > .05). Glove tears were present in 3.3% of gloves (50% in inner and 50% in outer gloves) and 1.7% of gloves (50% in inner and 50% in outer gloves) by electroconductivity and saline solution load testing, respectively. There was no significant association between glove tears and the number of epithelial cells found on the suture (P > .05). CONCLUSIONS: Epithelial cells were transmitted to the suture during simulated arthroscopic knot tying. However, despite multiple skin lacerations produced during knot-tying sessions, the number of cells transmitted was not significantly different when compared with the negative controls. The number of cells transmitted did not correlate with the number of knots tied and/or the presence of glove tears. CLINICAL RELEVANCE: Skin lacerations on the surgeon's fingers are often noted after arthroscopic knot tying. However, despite these skin lacerations, no skin tissue is transferred across the surgical gloves to the suture itself.

Retiform Sertoli-Leydig Cell Tumor in a 38-Year-Old Woman: A Case Report, Retrospective Review, and Review of Current Literature.

Ovarian sex cord-stromal tumors arise from the stromal cells that surround and support the oocytes. Sertoli-Leydig cell tumors belong to this category of ovarian neoplasms. We present the case of a 38-year-old woman who was found to have a right ovarian mass. The mass was resected and diagnosed as Stage I Sertoli-Leydig cell tumor, retiform variant, following histopathologic and immunohistochemical examination. This case is unusual given the rarity of the retiform variant of Sertoli-Leydig cell tumor and the atypically older age of 38 years at presentation.

Hidradenoma papilliferum associated with pregnancy: a case report.

We present the case of a 33-year-old female who developed a cystic nodule on the vulva during pregnancy. Immediately following Cesarean section, the lesion was biopsied and histologic examination revealed a dermal tumor composed of glandular structures arranged in a labyrinth pattern. The glandular structures displayed cytoplasmic vacuolization, large atypical nuclei, prominent nucleoli and scattered eosinophilic luminal secretions. Immunohistochemistry showed the tumor cells to be diffusely positive for CK7 and progesterone receptor with focal expression of mammaglobin and GCDFP-15. The tumor cells were negative for estrogen receptor and CK20. These histologic and immunophenotypic findings were consistent with hidradenoma papilliferum. Our unusual (and to our knowledge first reported) case demonstrates hidradenoma papilliferum in association with pregnancy and raises the possibility of cytologic atypia and lactational change being secondary to hormonal changes in pregnancy.

Collision of Ductal Carcinoma In Situ of Anogenital Mammary-like Glands and Vulvar Sarcomatoid Squamous Cell Carcinoma.

A spectrum of invasive adenocarcinomas presumably arising from the anogenital mammary-like glands of the vulva has been reported. Even rarer are the cases of pure ductal carcinoma in situ that originated from these unique glandular structures. Herein, we report an 81-yr-old woman presented with an invasive well-differentiated squamous cell carcinoma of the vulva. Unexpectedly, the underlying dermis demonstrated a cystically dilated structure that displayed a layer of malignant squamous cells in the periphery, and a second centrally located population of neoplastic cells exhibiting glandular differentiation. In addition, a spindle and pleomorphic malignant cell population consistent with a sarcomatoid carcinoma was identified around the cystic structure. Scattered benign anogenital mammary-like glands were present in the adjacent dermis. The histologic and immunohistochemical findings were consistent with those of vulvar squamous cell carcinoma that has undergone sarcomatoid transformation after spreading in a pagetoid fashion into an underlying focus of ductal carcinoma in situ of anogenital mammary-like gland origin.

Pulmonary artery intimal sarcoma diagnosed using endobronchial ultrasound-guided transbronchial needle aspiration.

Intimal sarcoma of the pulmonary artery is a rare intraluminal malignant neoplasm that has an aggressive biological behavior, and early diagnosis may improve patient outcome. We describe a case of pulmonary artery intimal sarcoma diagnosed on cytologic material obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy with rapid on-site evaluation (ROSE). The aspirate showed loosely cohesive clusters of pleomorphic malignant spindled and epithelioid cells. An immunostain panel did not demonstrate any definitive mesenchymal or epithelial differentiation. The tumor's intraluminal origin was supported by radiographic imaging studies. Subsequently, the patient received preoperative chemotherapy and underwent tumor resection with reconstruction. This report describes the cytomorphologic features of this rare intravascular tumor and demonstrates how EBUS-TBNA with ROSE was instrumental in obtaining optimal cytologic sampling for ancillary studies, thus expediting the management.

Concurrent primary peritoneal low-grade serous carcinoma and endometrial high-grade serous carcinoma.

A 64-yr-old postmenopausal woman with high-grade squamous intraepithelial lesion and atypical glandular cell of undetermined significance on her Pap test was found to have endometrial serous carcinoma (high grade) involving a polyp in a subsequent endometrial biopsy. She underwent hysterectomy and bilateral salpingo-oophorectomy with multiple biopsies of the peritoneum. Microscopic examination of the entirely submitted uterus showed no residual serous carcinoma. Multiple foci of low-grade serous tumor with extensive calcifications and psammoma bodies were identified on the surfaces of the left fallopian tube, ovaries, and biopsies of the peritoneum, consistent with peritoneal primary low-grade serous carcinoma. To our knowledge, this is the first reported case of low-grade serous carcinoma of the peritoneum with a concurrent (high-grade) serous carcinoma of the endometrium arising from an endometrial polyp.

GATA-binding protein 3 enhances the utility of gross cystic disease fluid protein-15 and mammaglobin A in triple-negative breast cancer by immunohistochemistry.

AIMS: We have demonstrated previously that gross cystic disease fluid protein-15 (GCDFP-15) and mammaglobin A (MAM) are of limited utility in triple-negative breast cancer (TNBC). GATA-binding protein 3 (GATA-3) is an emerging breast-associated immunohistochemical (IHC) marker with limited data in TNBC. Here, we examined GATA-3 expression in TNBC in comparison with GCDFP-15 and MAM. METHODS AND RESULTS: We studied GATA-3, GCDFP-15 and MAM IHC expression in 62 primary and 68 metastatic TNBCs. In primary TNBCs, GATA-3 staining was observed in 25 cases (40%), including 16 cases that were negative for GCDFP-15 and MAM. In metastatic TNBCs, GATA-3 staining was observed in 30 cases (44%), including 16 cases that were negative for GCDFP-15 and MAM. The expression frequency of any of the markers was 56% in primary and 62% in metastatic TNBCs. However, when focal staining was excluded, the expression frequency of any marker dropped to 31% and 44%, respectively. CONCLUSION: GATA-3 is expressed at a higher frequency by IHC in TNBC compared to GCDFP-15 and MAM, although the tissue specificity of the latter markers may be superior. When evaluating a triple-negative tumour, including GATA-3 in a panel of markers may increase the diagnostic accuracy for tissue origin in the appropriate clinical setting.

Uroplakin II is a more sensitive immunohistochemical marker than uroplakin III in urothelial carcinoma and its variants.

OBJECTIVES: Uroplakin (UP) II and UPIII are highly specific immunohistochemical markers for urothelial differentiation. Here we studied the sensitivity of UPII and UPIII in conventional and variant urothelial carcinomas (UCs). METHODS: Immunohistochemical staining for UPII and UPIII was performed on tissue microarray slides, including 105 conventional bladder UCs (BUCs), 90 upper urinary tract UCs (UUTUCs), and 47 micropapillary, 16 plasmacytoid, 22 small cell carcinoma, and 41 sarcomatoid UC variants. RESULTS: UPII expression was significantly higher than UPIII expression in conventional BUC (44% vs 17%, P < .001) and UUTUC (67% vs 46%, P = .045). UPIII expression was significantly higher in UUTUC than in BUC (P < .001). In UC variants, UPII expression was significantly higher than UPIII expression in micropapillary (91% vs 25%, P < .001), plasmacytoid (63% vs 6%, P < .001), and sarcomatoid (29% vs 5%, P = .032) variants. Only rare cases of the small cell carcinoma variant had focal UPII and UPIII expression. Compared with conventional UC, the sarcomatoid variant had significantly lower UPII expression, whereas the micropapillary variant had significantly higher UPII expression (P < .001). CONCLUSIONS: UPII demonstrates a significantly higher sensitivity than UPIII in conventional and variant UCs. Thus, UPII is a more valuable marker than UPIII in immunohistochemical analyses for confirming the urothelial origin of carcinomas.

Cross-talk between EphA2 and BRaf/CRaf is a key determinant of response to Dasatinib.

PURPOSE: EphA2 is an attractive therapeutic target because of its diverse roles in cancer growth and progression. Dasatinib is a multikinase inhibitor that targets EphA2 and other kinases. However, reliable predictive markers and a better understanding of the mechanisms of response to this agent are needed. EXPERIMENTAL DESIGN: The effects of dasatinib on human uterine cancer cell lines were examined using a series of in vitro experiments, including MTT, Western blot analysis, and plasmid transfection. In vivo, an orthotopic mouse model of uterine cancer was utilized to identify the biologic effects of dasatinib. Molecular markers for response prediction and the mechanisms relevant to response to dasatinib were identified by using reverse phase protein array (RPPA), immunoprecipitation, and double immunofluorescence staining. RESULTS: We show that high levels of CAV-1, EphA2 phosphorylation at S897, and the status of PTEN are key determinants of dasatinib response in uterine carcinoma. A set of markers essential for dasatinib response was also identified and includes CRaf, pCRaf(S338), pMAPK(T202/Y204) (mitogen-activated protein kinase [MAPK] pathway), pS6(S240/244), p70S6k(T389) (mTOR pathway), and pAKT(S473). A novel mechanism for response was discovered whereby high expression level of CAV-1 at the plasma membrane disrupts the BRaf/CRaf heterodimer and thus inhibits the activation of MAPK pathway during dasatinib treatment. CONCLUSIONS: Our in vitro and in vivo results provide a new understanding of EphA2 targeting by dasatinib and identify key predictors of therapeutic response. These findings have implications for ongoing dasatinib-based clinical trials.

Spontaneous hip dislocation secondary to intraarticular neurofibroma: a case report.

Spontaneous hip dislocation due to intraarticular neurofibroma in patients with neurofibromatosis type 1 is extremely rare. We describe the imaging features of spontaneous dislocation of hip due to histologically proven intraarticular neurofibroma in young woman with neurofibromatosis type 1, and review the literature.

ERG and FLI1 protein expression in epithelioid sarcoma.

Epithelioid sarcoma is a rare, aggressive keratin-positive sarcoma that co-expresses CD34 in 50% of cases and may mimic an angiosarcoma. Recently, we have observed one case of epithelioid sarcoma that labeled for ERG, an ETS family regulatory transcription factor, which is considered to be a reliable marker for vascular differentiation. We investigated the prevalence of nuclear expression of ERG and FLI1, a homologous transcription factor, in these tumors. A formalin-fixed paraffin-embedded tissue microarray of 37 epithelioid sarcomas was examined. Immunohistochemistry was performed using anti-ERG monoclonal antibody to the N-terminus, anti-ERG monoclonal antibody to the C-terminus and anti-FLI1 monoclonal antibody. Comparison was made with CD34, CD31, and D2-40 labeling. The extent of immunoreactivity was graded according to the percentage of positive tumor cell nuclei (0: no staining; 1+: <5%; 2+: 5-25%; 3+: 26-50%; 4+: 51-75%; and 5+: 76-100%), and the intensity of staining was graded as weak, moderate, or strong. Nuclear staining for the N-terminus of ERG was seen in 19 out of 28 cases: 10 with diffuse(4 to 5+) strong/moderate labeling; 1 with 2+ moderate labeling and 8 with weak labeling (1 to 4+, 2 each). Focal staining for the C-terminus of ERG was seen in only 1 out of 29 cases (2+ moderate). FLI1 labeling was seen in nearly all (28 out of 30) cases: 16 with diffuse (5+) predominantly moderate labeling, and 8 cases with diffuse(5+) weak labeling. The remainder had variable moderate (1 to 3+) or weak (1 to 4+) FLI1 staining. CD34 was positive in 22 out of 30 cases and D2-40 was found to be positive in 22 out of 31 cases. All cases were negative for CD31 (0 out of 30). Epithelioid sarcoma can label with antibodies to the N-terminus of ERG, FLI1, and D2-40, which may cause diagnostic confusion for a vascular tumor. A panel of other antibodies including SMARCB1 and CD31 should be used in evaluating these tumors. ERG antibody selection is also critical, as those directed against the C-terminus are less likely to label epithelioid sarcoma.

Endometrioid stromal sarcoma: a clinicopathologic study of 63 cases.

Endometrioid stromal sarcoma (also known as extrauterine endometrial stromal sarcoma [EESS]) is an uncommon tumor that occurs in women over a wide age range. The extrauterine location, non-gynecologic symptoms and signs at presentation, and confounding histologic features can pose a diagnostic challenge. In this study, we present the clinicopathologic features of 63 cases of EESS seen during a period of 21 years at our institution. Clinical information and pathology material were reviewed. Ages ranged from 27 to 87 years (median: 50 years). The most common symptoms and signs were an abdominal or pelvic mass, pain, vaginal bleeding, and gastrointestinal symptoms. The tumor size ranged from 1.2 to 24.5 cm. The most common sites of involvement were the ovaries (25), bowel wall (28), abdomen/peritoneum (37), pelvis (20), and vagina (6). Multiple sites were involved in 40 cases. Forty-six of 49 tumors had a classic microscopic appearance, and 3 had dedifferentiation; in 20 cases, there was vascular invasion. Fibroma-like stroma was seen in 30, hyaline plaques in 23, sex cord elements in 11, smooth muscle differentiation in 4, and myxoid change in 4 cases. Endometriosis was noted in 30 cases. Immunohistochemical results included: CD10 positivity in 31, desmin positivity in 9 (focal), estrogen receptor positivity in 28, and progesterone receptor positivity in 33 cases. In 25% of cases, an initial diagnosis other than EESS was made: sex cord-stromal tumors (4), gastrointestinal stromal tumor (3), leiomyosarcoma (3), liposarcoma (1), müllerian adenosarcoma (1), synovial sarcoma (1), malignant peripheral nerve sheath tumor (1), small round blue cell tumor (1), and atypical stromal endometriosis (1). Primary treatment was cytoreductive surgery for 61 patients and hormonal therapy for 2 patients. Adjuvant treatment included hormonal therapy, chemotherapy, and radiation therapy. Follow-up (5 to 336 months) information was available for 53 patients: alive with no evidence of disease, 29; alive with disease, 15; and dead of disease, 9 (median period of 70 months from diagnosis to death). Thirty-three patients had recurrent disease, and 10 patients were lost to follow-up. EESS is commonly associated with endometriosis and tends to be indolent with a propensity for recurrence. Seven of 9 patients who died of the disease had bowel involvement, and 3 had tumors with dedifferentiation. Besides the latter, no other histologic finding correlated with the clinical behavior of these tumors.

A 2-stage ovarian cancer screening strategy using the Risk of Ovarian Cancer Algorithm (ROCA) identifies early-stage incident cancers and demonstrates high positive predictive value.

BACKGROUND: A 2-stage ovarian cancer screening strategy was evaluated that incorporates change of carbohydrate antigen 125 (CA125) levels over time and age to estimate risk of ovarian cancer. Women with high-risk scores were referred for transvaginal ultrasound (TVS). METHODS: A single-arm, prospective study of postmenopausal women was conducted. Participants underwent an annual CA125 blood test. Based on the Risk of Ovarian Cancer Algorithm (ROCA) result, women were triaged to next annual CA125 test (low risk), repeat CA125 test in 3 months (intermediate risk), or TVS and referral to a gynecologic oncologist (high risk). RESULTS: A total of 4051 women participated over 11 years. The average annual rate of referral to a CA125 test in 3 months was 5.8%, and the average annual referral rate to TVS and review by a gynecologic oncologist was 0.9%. Ten women underwent surgery on the basis of TVS, with 4 invasive ovarian cancers (1 with stage IA disease, 2 with stage IC disease, and 1 with stage IIB disease), 2 ovarian tumors of low malignant potential (both stage IA), 1 endometrial cancer (stage I), and 3 benign ovarian tumors, providing a positive predictive value of 40% (95% confidence interval = 12.2%, 73.8%) for detecting invasive ovarian cancer. The specificity was 99.9% (95% confidence interval = 99.7%, 100%). All 4 women with invasive ovarian cancer were enrolled in the study for at least 3 years with low-risk annual CA125 test values prior to rising CA125 levels. CONCLUSIONS: ROCA followed by TVS demonstrated excellent specificity and positive predictive value in a population of US women at average risk for ovarian cancer.

Poor survival with wild-type TP53 ovarian cancer?

OBJECTIVE: The objective of this study is to investigate whether wild-type TP53 status in high-grade serous ovarian carcinoma is associated with poorer survival. METHODS: Clinical and genomic data of 316 sequenced samples from The Cancer Genome Atlas (TCGA) ovarian high-grade serous carcinoma study were downloaded from TCGA data portal. Association between wild-type TP53 and survival was analyzed with Kaplan Meier method and Cox regression. The diagnosis of high-grade serous carcinomas was evaluated by reviewing pathological reports and high-resolution hematoxylin and eosin (H&E) images from frozen sections. The authenticity of wild-type TP53 in these tumor samples was assessed by analyzing SNP array data with ASCAT algorithm, reverse phase protein array (RPPA) data and RNAseq data. RESULTS: Fifteen patients with high grade serous ovarian carcinomas were identified to have wild-type TP53, which had significantly shorter survival and higher chemoresistance than those with mutated TP53. The authenticity of wild-type TP53 status in these fifteen patients was supported by SNP array, RPPA, and RNAseq data. Except four cases with mixed histology, the classification as high grade serous carcinomas was supported by pathological reports and H&E images. Using RNAseq data, it was found that EDA2R gene, a direct target of wild-type TP53, was highly up-regulated in samples with wild-type TP53 in comparison to samples with either nonsense or missense TP53 mutations. CONCLUSION: Although patients with wild-type TP53 ovarian cancer were rare in the TCGA high grade ovarian serous carcinomas cohort, these patients appeared to have a poorer survival and were more chemoresistant than those with mutated TP53. Differentially expressed genes in these TP53 wild-type tumors may provide insight in the molecular mechanism in chemotherapy resistance.

Galectin-7 levels predict radiation response in squamous cell carcinoma of the cervix.

OBJECTIVE: We previously found that galectin-7 was upregulated in patients with cervical cancer who remained recurrence-free after chemoradiation. We hypothesized that pretreatment levels of galectin-7 predict radiation response in patients with squamous cell carcinoma (SCC) of the cervix. METHODS: Galectin-7 expression was assessed by immunohistochemical staining of a tissue microarray of paraffin-embedded specimens from 161 patients with cervical SCC treated with definitive radiation therapy in 1980-1999. Galectin-7 expression was scored as absent or present. Distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS) were computed using the Kaplan-Meier method and log-rank tests. RESULTS: The median age at diagnosis was 45 years (range 21-85) and median follow-up interval was 71 months (range 0-285). Of the 161 patients, 105 (65%) had FIGO stage IB disease, 18 (11%) stage IIA, and 38 (24%) stage IIB. Median tumor diameter was 5.5 cm (range 3.5-8). Seven patients (4%) received concurrent chemotherapy; 139 patients (86%) had galectin-7-positive tumors and 22 (14%) galectin-7-negative tumors. Five-year DMFS rates for patients with galectin-7-positive versus -negative tumors were 73% and 55% (p=0.05); DSS, 65% and 36% (p=0.004); and OS, 64% and 36% (p=0.005). In multivariate analysis adjusting for age, stage, and tumor diameter, galectin-7 expression remained a significant predictor of DMFS (hazard ratio [HR]=0.43, p=0.03), DSS (HR=0.34, p=0.001), and OS (HR=0.34, p=0.001). CONCLUSIONS: Elevated galectin-7 expression is associated with improved outcomes after radiation therapy for cervical cancer. Further studies are required to validate these findings and clarify the role of galectin-7 in disease progression and radiation response.

Ovarian serous carcinoma associated with a distinct "corded and hyalinized" pattern.

The "corded and hyalinized" pattern, described in endometrioid carcinoma, has not been previously reported in association with serous carcinoma. We describe a unique case of serous neoplasm of low malignant potential with low-grade serous carcinoma combined with a distinct pattern of high-grade carcinoma characterized by cords of epithelioid and spindled cells enmeshed in a hyalinized, collagenous stroma. This pattern was the predominant architecture in the patient's recurrence and caused a diagnostic challenge, as the splenic recurrence was initially diagnosed as a second primary high-grade spindle cell neoplasm. Both ovarian and splenic tumors displayed positive immunohistochemical staining for cytokeratin 7, cytokeratin 8/18, estrogen receptor, and paired box gene 8 (PAX-8) in the conventional serous carcinoma and the corded and hyalinized component, confirming the diagnosis of recurrent carcinoma. The behavior in this unique case of serous carcinoma associated with a distinct corded and hyalinized pattern was more aggressive than low-grade serous carcinoma, but more favorable than malignant mixed mullerian tumor.

Src activation by ß-adrenoreceptors is a key switch for tumour metastasis.

Noradrenaline can modulate multiple cellular functions important for cancer progression; however, how this single extracellular signal regulates such a broad array of cellular processes is unknown. Here we identify Src as a key regulator of phosphoproteomic signalling networks activated in response to beta-adrenergic signalling in cancer cells. These results also identify a new mechanism of Src phosphorylation that mediates beta-adrenergic/PKA regulation of downstream networks, thereby enhancing tumour cell migration, invasion and growth. In human ovarian cancer samples, high tumoural noradrenaline levels were correlated with high pSrc(Y419) levels. Moreover, among cancer patients, the use of beta blockers was significantly associated with reduced cancer-related mortality. Collectively, these data provide a pivotal molecular target for disrupting neural signalling in the tumour microenvironment.

Posttraumatic intramedullary osteochondroma: report of a case.

We present a rare osteochondroma, which instead of being the usual exophytic growth outside bone, grew inward into the medullary cavity of distal femur in a patient with prior trauma to his knee. Except for its intramedullary location, the benign tumor had all the classic radiographic and pathologic features of typical osteochondroma.