Surgical management of a large retroperitoneal liposarcoma: A case study.

The patient was a 45-year-old male who initially presented with a left hydrocele. During radiographic work-up, a 26 cm right retroperitoneal lipoma was incidentally discovered. Despite a recommendation for preoperative radiation therapy followed by surgery from the sarcoma multispecialty team, the patient opted for surgery alone, in the hopes of avoiding damage or loss of his right kidney. Following surgical excision of the 39 cm well-differentiated liposarcoma, with removal of the perinephric fat adjacent to the tumor thereby preserving the kidney, he was discharged home after two nights in the hospital. Follow-up imaging eight months later showed no recurrence.

Combined Tumors in Hematolymphoid Neoplasms: Case Series of Histiocytic and Langerhans Cell Sarcomas Arising From Low-Grade B-Cell Lymphoma.

We report an index case of histiocytic sarcoma arising in a 70-year-old patient with long-standing chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The patient presented in 2017 with painful, enlarging swelling of the left neck. He had remote history of cutaneous squamous cell carcinoma with no sign of recurrence, and his CLL/SLL was thought to be in remission. Computed tomography showed mild splenomegaly and multifocal lymphadenopathy including a 3-cm left neck mass. Biopsy of the left neck mass showed CLL/SLL with associated histiocytic sarcoma. Flow cytometry demonstrated a B cell neoplasm with CLL/SLL phenotype. Despite radiation therapy, he expired 3 months after presentation. Two similar cases (CLL/SLL and histiocytic sarcoma, follicular lymphoma and Langerhans cell sarcoma) from another institution are also illustrated. The pathological features of combined tumors in lymphoid neoplasms, a general framework to the work-up to determine interrelatedness of tumor components, and the clinical relevance are discussed.

Genomic Status of MET Potentiates Sensitivity to MET and MEK Inhibition in NF1-Related Malignant Peripheral Nerve Sheath Tumors.

Malignant peripheral nerve sheath tumors (MPNST) are highly resistant sarcomas that occur in up to 13% of individuals with neurofibromatosis type I (NF1). Genomic analysis of longitudinally collected tumor samples in a case of MPNST disease progression revealed early hemizygous microdeletions in NF1 and TP53, with progressive amplifications of MET, HGF, and EGFR To examine the role of MET in MPNST progression, we developed mice with enhanced MET expression and Nf1 ablation (Nf1fl/ko;lox-stop-loxMETtg/+;Plp-creERTtg/+ ; referred to as NF1-MET). NF1-MET mice express a robust MPNST phenotype in the absence of additional mutations. A comparison of NF1-MET MPNSTs with MPNSTs derived from Nf1ko/+;p53R172H;Plp-creERTtg/+ (NF1-P53) and Nf1ko/+;Plp-creERTtg/+ (NF1) mice revealed unique Met, Ras, and PI3K signaling patterns. NF1-MET MPNSTs were uniformly sensitive to the highly selective MET inhibitor, capmatinib, whereas a heterogeneous response to MET inhibition was observed in NF1-P53 and NF1 MPNSTs. Combination therapy of capmatinib and the MEK inhibitor trametinib resulted in reduced response variability, enhanced suppression of tumor growth, and suppressed RAS/ERK and PI3K/AKT signaling. These results highlight the influence of concurrent genomic alterations on RAS effector signaling and therapy response to tyrosine kinase inhibitors. Moreover, these findings expand our current understanding of the role of MET signaling in MPNST progression and identify a potential therapeutic niche for NF1-related MPNSTs.Significance: Longitudinal genomic analysis reveals a positive selection for MET and HGF copy number gain early in malignant peripheral nerve sheath tumor progression. Cancer Res; 78(13); 3672-87. ©2018 AACR.

Inguinal canal spermatic cord leiomyoma presenting as an incarcerated inguinal hernia.

Leiomyoma is a benign neoplasm originating from smooth muscle cells and is most commonly seen in the uterus, followed by the small bowel and oesophagus. We report a rare case of a 41-year-old male patient with a spermatic cord leiomyoma that presented as an inguinal canal mass mimicking an irreducible inguinal hernia without scrotal involvement. This report highlights the rare presentation and workup of an inguinal mass, importance of intraoperative decision making based on operative findings and the significance of postoperative pathology findings.

Spindle Cell Lipomas in Women: A Report of 53 Cases.

Spindle cell lipomas (SCL) are typically tumors of the upper back/neck (shawl region) of men (80% to 90%). In general, there is a frequent tendency to restrict the diagnosis to this specific clinical scenario and a hesitancy to diagnose SCL in women. We hypothesized that SCL in women have a more varied presentation. A total of 395 SCL were diagnosed at our institution over the last 11 years. The diagnosis of SCL in women was confirmed by re-review. Immunohistochemical stains for CD34, desmin, estrogen receptor, and p16 were performed. In a subset, fluorescence in situ hybridization to detect Retinoblastoma1 (RB1) gene deletion was performed. Of 395 SCLs, 331 (86%) occurred in men; 53 (14%) occurred in women (11 cases excluded). Of the 64 SCL in women, 58 had available material. In total, 53 of 58 were confirmed as SCL. Women were younger at diagnosis (median, 51 y; range, 5 to 76 y) compared with men (64 y; range, 23 to 98 y), P<0.0001, t test. SCL in women typically occurred outside the shawl distribution (36/53, 68%) compared with men (95/331, 29%) (P<0.001), including extremities (16/53, 30% vs. 32/331, 10%) and face (11/53, 21% vs. 47/331, 14%). Dermal SCL in women were also relatively common (16/53, 30%). The cases demonstrated varying proportions of bland spindled cells, ropey collagen, myxoid matrix, and adipocytes. By immunohistochemistry, 46/46 were CD34, 48 of 48 were desmin negative, 33 of 42 were estrogen receptor negative, and 29 of 42 had loss of p16 expression. In total, 12 of 14 showed RB1 loss by fluorescence in situ hybridization. SCL in women frequently occurs in unconventional locations and in at a slightly younger patient age.

Bronchogenic cyst arising from the crus of the left hemidiaphragm.

A 34-year-old man presented with chronic worsening left-sided retrosternal chest pain. Following a negative cardiac work up he was found, on cross-sectional imaging, to have a cystic mass measuring 9.6×11.8×9 cm related to his left diaphragmatic crus. The patient underwent an exploratory laparotomy with complete resection of the cystic mass. Histopathological examination of the mass confirmed it as being a bronchogenic cyst. His pain resolved following excision of the mass and at follow-up he was asymptomatic with no evidence of recurrence on imaging.

Histone H1.5, a novel prostatic cancer marker: an immunohistochemical study.

Histone H1.5 (HH1.5) is a somatic subtype of the histone H1 family of linker proteins that are located in the nucleus and play a role in stabilizing higher-order chromatin structure, gene expression, DNA repair, and cell proliferation. Recently, differential immunohistochemical expression of HH1.5 has been found in various neuroendocrine neoplasms. This study aimed to investigate the immunohistochemical expression of HH1.5 in prostatic adenocarcinomas. Sixty-three prostate needle core biopsies, 9 radical prostatectomy specimens, and 3 metastatic prostate cancer cases were evaluated. HH1.5 immunohistochemistry revealed strong nuclear reactivity in 68 (93%) of 73 cases of prostate adenocarcinomas, compared to only 7 (9%) of 75 cases of benign prostatic glands (P ≤ .0001). In all positive benign prostate epithelium, HH1.5 was limited to focal and weak reactivity. Similarly, all 23 foci of high-grade prostatic intraepithelial neoplasia exhibited focal staining, with the vast majority having only weak nuclear reactivity. Increased HH1.5 reactivity was observed in Gleason patterns 4 and 5 as compared to Gleason pattern 3, 72% and 56%, respectively (P ≤ .02). All 3 metastatic prostate cancer cases showed strong nuclear reactivity. HH1.5 may be a useful diagnostic tool in evaluating prostatic biopsies, particularly with small foci of cancer. Further studies are needed to support these findings and investigate the possible prognostic significance of HH1.5 in prostatic adenocarcinomas.

Case report of undifferentiated endometrial sarcoma in association with osteoclast-like giant cells.

We describe the clinical, gross and microscopic features of undifferentiated uterine stromal sarcoma associated with osteoclast-like giant cells. A case of low-grade endometrial stromal sarcoma is already described in association with osteoclast-like giant cells; however, the current case differs in that the tumor was a high grade and did not show any evidence of smooth muscle or epithelioid differentiation and was shown to be strongly positive for CD10 and focally for WT-1 and Inhibin supporting an endometrial stromal origin. The associated osteoclast-like giant cells were abundant, evenly distributed within the tumor and showed strong positivity for CD68. Interestingly, rare (less than 2%) giant cells also showed weak cytoplasmic positivity for b-hCG. The tumor infiltrated deep into the myometrium and had marked lymphovascular invasion. Although the regional lymph nodes and peritoneal washings were negative, the lesion showed a highly aggressive clinical course. Despite treatment, the tumor disseminated within the abdominal cavity and lungs and ultimately led to the patient's demise within 9 months of the diagnosis.