Ultrastructurally confirmed myofibrosarcoma: a series of 10 new cases, with a discussion on diagnostic criteria.

Some view ultrastructure as key to myofibrosarcoma diagnosis, whereas others argue that electron microscopy is too little used in contemporary practice to be considered an important diagnostic tool. These views are discussed in the context of 10 ultrastructurally confirmed cases of myofibrosarcoma, some occurring at rare sites such as skin and penis. Patient age ranged from 21 to 83 years, with a 6:4 male to female ratio. Size ranged from 2 to 7.5 cm and all had infiltrative margins. Histologically, all consisted of variably cellular fascicles of spindle cells with mild to moderately pleomorphic nuclei, small punctate nucleoli, and eosinophilic cytoplasm. All cases showed α-smooth muscle actin positivity and 2 showed very focal weak positivity for desmin. Ultrastructurally, the tumor cells contained rough endoplasmic reticulum, mainly peripheral smooth-muscle myofilaments, and fibronectin fibrils or fibronexus junctions at the cell surface. The most confident diagnosis of myofibrosarcoma is provided by ultrastructural examination. However, given the right histological appearance, use of a panel of antibodies that includes α-smooth muscle actin, desmin, and h-caldesmon, serves as an acceptable practical way of diagnosing myofibrosarcoma.

The accuracy of the sentinel node procedure after excision biopsy in squamous cell carcinoma of the vulva.

INTRODUCTION: Restricting inguinofemoral lymphadenectomy to patients with malignant nodes would reduce treatment-related morbidity in vulval cancer patients. A prospective study was conducted to determine the diagnostic accuracy of the Sentinel Lymph Node (SLN) procedure in vulval cancer patients referred following either diagnostic or excision biopsy. METHODS: Patients with clinical stage I and II squamous cell carcinoma of the vulva underwent SLN identification with peri-scar/lesional injection of (99m)Technetium-labelled nanocolloid (pre-operative lymphoscintigraphy and intra-operative use of a hand-held probe) and intra-operative blue dye. Radical excision of the vulval tumour or scar and formal inguinofemoral lymphadenectomy was then performed as necessary. SLN were processed separately and further examined at multiple levels to exclude micrometastases (H&E/cytokeratin staining) if negative on routine analysis. Clinical follow-up was carried out to identify and treat recurrences or treatment-related morbidity. RESULTS: Thirty-two women took part. Fifteen were referred following excision biopsy and seventeen following diagnostic biopsy of their primary vulval tumour. One or more SLN was successfully detected intra-operatively in 31 patients (97%) and 45 groins. An SLN could not be identified intra-operatively in one case (re-excision of scar). On average, more SLN were identified in patients with their primary vulval lesion in situ compared with those whose tumour had previously been excised (2.6 vs. 1.8, p = 0.03). Midline tumours were more likely (15/17) than lateral tumours (1/15) to have bilateral SLN identified pre-operatively. Two patients with midline tumours previously excised had unilateral SLN. Seven patients (23%) and ten groins had inguinofemoral lymph node metastases. The SLN procedure correctly identified inguinofemoral metastases in six patients (nine groins). In one case (midline tumour, re-excision of scar) the sentinel node was positive on one side but false negative on the other. CONCLUSIONS: The SLN procedure may be used to identify malignant groins in selected patients with vulval cancer. The extent to which previous vulval surgery might influence the accuracy of the SLN procedure deserves further investigation.