Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma - a rare vascular neoplasm with deceptive morphology and distinctive immunophenotype.

Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma is a rare, low grade vascular (endothelial) neoplasm typically presenting as multicentric, superficial to deep nodules in extremities with a slight tendency of affecting young adult males. We report a case of pseudomyogenic hemangioendothelioma in a 15-year-old boy presenting initially with a 1 cm right thigh painless cutaneous lump. The lump was excised with the clinical impression of a sebaceous cyst. On microscopy, a poorly circumscribed, mild to moderately atypical spindle cell lesion in fascicular and storiform patterns with strikingly myoid-like eosinophilic cytoplasm was identified. The spindle cells were highlighted by pancytokeratin AE1/AE3, CD31, and ERG with retained INI-1, while being negative for MNF116, S100, CD34, EMA, desmin, SMA, caldesmon, myogenin, MyoD1, HHV-8 and CD163. Following the first diagnostic report, a positron emission tomography-computed tomography (PET-CT) scan revealed another 4 cm ill-defined nodule accompanied by a smaller adjacent 0.7 cm ipsilateral satellite nodule within the right psoas muscle that displayed similar morphology and immunophenotype as the cutaneous lump, supporting the multicentric feature of this unique entity. It is an uncommon yet increasingly recognised neoplasm of endothelial origin possessing a misleading myoid morphology and distinctive immunophenotype worth notifying.

Giant labial fibroepithelial stromal polyp.

We report an18-year-old girl with a four-year history of a slow-growing labial mass with a sudden increase in size in the last year. Examination revealed a large fleshy 20 cm perineal mass centering on the left labia majora and attached to it by a 1cm pedicle. It was associated with pain, ulceration and discharge. The lesion was excised via diathermy at the base of the stalk. The excised specimen weighed 1.112kg and measured 20.5 x 17 x 5cm. The lesion showed a solid, soft whitish, cut surface. Histology revealed a hypocellular tumour with focally oedematous fibrous stroma in which were scattered large and small blood vessels, mast cells and other chronic inflammatory cells. True myxoid matrix was not observed. The stromal cells had a spindle to stellate morphology. There was no significant cytological atypia, mitotic activity or necrosis. The tumour cells were negative for SMA, desmin, CD34, S100 protein, EMA and PR. The diagnosis was clinically and histologically challenging because various vulvovaginal soft tissue tumours often have overlapping clinicopathological features. However, based on strict histological criteria and the absence of worrisome cytological features, a diagnosis of fi broepithelial stromal polyp was rendered despite the unusual size. A review of the literature shows that whilst vulvovaginal fibroepithelial stromal polyps are well described, giant variants are rare. Awareness of the extraordinary size that can be attained by such polyps can facilitate swift clinical and histological diagnosis.

Primary papillary carcinoma in a thyroglossal cyst--a case report.

A benign thyroglossal cyst is a common clinical condition and is second only to a cervical lymph node as the most common cause of a solitary neck swelling. Primary carcinoma of a thyroglossal cyst, however, is rare and has been described in only 115 cases in the literature. The malignant cysts are clinically difficult to differentiate from benign lesions and the diagnosis often rests on histopathological examination. Before initiating treatment, primary papillary carcinoma of the thyroid gland must be excluded. The treatment options range from simple excision to a Sistrunk operation with concurrent cervical lymph node dissection. We describe here a case of papillary carcinoma of a thyroglossal cyst and review the 115 reported cases.

Erdheim-Chester disease: a rare cause of interstitial lung disease.

Erdheim-Chester disease is a non-Langerhans cell histiocytosis that is progressive and may lead on to multi-organ involvement. Pulmonary involvement is rare, its presentation is nonspecific, and it carries an adverse outcome. Several radiological features, when considered together, may point to the diagnosis. This condition should be considered in the differential diagnosis of interstitial lung disease. We describe a 39-year-old woman who presented with dry cough, malaise and progressive dyspnoea. She was diagnosed to have late stage interstitial lung disease due to Erdheim-Chester disease.