A rare case of collision tumour of the ovary complicated by torsion

Collision tumour is the coexistence of two adjacent, but histologically distinct tumours without histologic admixture. Collision tumours are rare in the ovary. It is mostly a histopathological diagnosis often missed in preoperative imaging. The radiologist, gynaecologists and pathologists should be aware of such a combination of tumours to avoid misdiagnosis. We describe the finding of a rare collision tumour, mature cystic teratoma and ovarian fibroma complicated by torsion.

1000 Basal-Squamous Cell Carcinoma Collision Tumour Of the Preauricular Region

Collision tumours are defined as multiple neoplasms adjacent to each other or combined in one area and are particularly rare, with only one other basal-squamous cell carcinoma combination of the head and neck region published in the literature. Case description An 87-year-old farmer presented to the Maxillofacial Surgery department following referral by his general practitioner concerned with multiple suspected skin neoplasms. Four lesions were identified, two of which required surgical excision with 4mm margins. Following histological investigation, the lesion in the right preauricular area was identified as a basal-squamous cell carcinoma collision tumour which was completely excised with clear margins. Discussion This case highlights the possibility of multiple skin neoplasms in a single site and gives an insight into the surgical management of a basal-squamous cell carcinoma collision tumour while aiming to increase clinician awareness of collision tumours especially in high-risk sites such as the head and neck. This case suggests that a 4-5mm surgical margin may be sufficient in removing similar presentations of basal-squamous cell carcinoma collision tumours however highlights the importance of appropriate histological examination of specimens not only to correctly diagnose the tumour but to ensure surgical margins are clear to mitigate recurrence risk. It must be noted that systemic metastases are more common in squamous cell carcinoma than in basal cell carcinoma cases and therefore it is possible that basal-squamous cell carcinoma collision tumours may have higher rates of metastases than traditional basal cell carcinomas.

Lactating Adenoma Co-Existing with High Grade Invasive Ductal Carcinoma; Collision Tumour or Mere Co-Incidence

Background: Lactating adenoma are benign lesions that can presents as a solitary or multiple freely movable breast mass during pregnancy or puerperium. The lesion is actually a localized focus of hyperplasia in the lactating breast, which may also develop in ectopic locations such as the axilla, chest wall, or vulva. Breast cancer developing during pregnancy or puerperium is known as pregnancy associated breast cancer. We report a case of lactating adenoma co-existing with high grade invasive ductal carcinoma in young patient in puerperium with a positive family history of breast cancer. We present a 19-year-old female with a palpable mass on her right upper outer quadrant of her right breast measuring 5x4x2cm with ipsilateral supraclavicular lymph node enlargement. Cytomorphology of the lesion showed tumour cells arranged in nests and solid sheets with abundant fibromyxoid stroma. Also seen are abnormal mitosis and areas of lymphovascular invasion. Proliferating glands are seen lined by cuboidal cells with cytoplasmic vacuolations. Immunohistochemical stain show tumour cells were triple negative (negative for progesterone receptor (PR), estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) and strongly positive for EMA in both tumours. Conclusion: This study indicated that lactating adenoma can co-exist with high grade invasive ductal carcinoma in a young patient in puerperium. The fact that this patient has a positive family history of breast cancer in first degree relative may explain the presentation at a very young age. It may be very difficult to ascertain whether this is a collision tumour or a mere co-incidence of lactating adenoma with breast cancer in this patient.

Collision tumour of two nodal metastases (adenocarcinoma and mast cell tumour) in a dog

An 11-year-old female neutered Labrador retriever was referred for a large vulvar mast cell tumour that extended into the vagina. Abdominal ultrasound revealed an enlarged right medial iliac lymph node, and cytology of the node was consistent with an endocrine/neuroendocrine tumour. An approximately 1.5-cm right anal sac mass was palpated. Medial iliac lymphadenectomy via ventral celiotomy, right anal sacculectomy and marginal vulvar mass resection were performed. Histopathology was consistent with right anal sac adenocarcinoma, vulvar mast cell tumour, and the right medial iliac lymph node showed a metastatic collision of both the adenocarcinoma and mast cell tumour cell populations. Adjunctive chemotherapy and radiotherapy were recommended to address the risk of local recurrence and further metastasis but were declined by the owner. The dog remains alive and asymptomatic with no visible evidence of recurrence 14 months after initial presentation.