High-grade transformation/dedifferentiation of an adenoid cystic carcinoma of the minor salivary gland to myoepithelial carcinoma

Lacrimal Gland Adenoid Cystic Carcinoma with High Grade Transformation: A Case Report and Current Concepts in Multi Modality Management

Lacrimal gland adenoid cystic carcinoma (AdCC) is associated with an aggressive clinical course and grave prognosis. A high grade transformation within adenoid cystic carcinoma of lacrimal gland is a rare condition which is even more locally aggressive with frequent neck and distant metastasis. We present a case of left lacrimal gland adenoid cystic carcinoma with high grade transformation to adenocarcinoma NOS type presenting with orbital pain and proptosis. After thorough evaluation for locoregional and distant spread of the disease, the patient underwent left orbital exenteration with orbitectomy and neck dissection with free flap reconstruction. Patient received adjuvant radiation therapy and is presently disease free for last 6 months. A multi-modality management protocol involving surgery, radiotherapy and chemotherapy has been proposed for management of lacrimal gland AdCC with high grade transformation. We report the 4th case in the literature of lacrimal gland adenoid cystic carcinoma with high grade transformation.

Primary cutaneous adenoid cystic carcinoma: a clinicopathologic, immunohistochemical, and fluorescence in-situ hybridisation study of 13 cases

AIMS

This study aimed to investigate the clinical, histological, immunohistochemical and chromosomal features of primary cutaneous adenoid cystic carcinoma (PCACC).

METHODS AND RESULTS

We retrospectively analysed 13 cases identified on their clinicopathological features and performed fluorescence in-situ hybridisation (FISH) on six available cases. Head and neck (46.2%) were most commonly involved. The median age was 53 years, with a male predilection. Histologically, tumours were classified as grades 1 (eight), 2 (four) and 3 with high-grade transformation (HGT) (one). The HGT component was demonstrated as poorly differentiated carcinoma with multifocal necrosis and myoepithelial differentiation. Patients with one of the following factors: longest diameter of the lesion (≥ 1 cm), involvement of subcutaneous fat tissue and widely infiltrative border had a relatively higher rate of local recurrence, distant metastasis and death. Five of six cases were confirmed to have MYB translocation, while nuclear staining for MYB proto-oncogene, transcription factor (MYB) protein was found in four cases. During the follow-up (median = 64 months), two patients experienced local recurrences. One patient, who was classified as grade III PCACC with HGT, developed multiple metastases and died of disease. Another patient was alive with multiple metastases.

CONCLUSIONS

This is the largest single-institution study, to our knowledge, of PCACC in an Asian population. We describe the first case of scalp PCACC with HGT, which is the only death case in our series. PCACC tends to recur locally and has metastatic potential. PCACC with HGT has a poor prognosis.

Dedifferentiated secretory breast carcinoma with fibrosarcomatous features harboring an ETV6-NTRK3 fusion in both components

Secretory carcinomas are low-grade translocation-driven carcinomas occurring in patients over a wide age range. These tumors most frequently arise in the breast and salivary gland, but may occasionally arise at other anatomic sites, such as the skin, the thyroid gland or the upper or lower respiratory tract. In concert with their low-grade morphology, secretory carcinomas most often follow an indolent clinical course. However, rare cases have shown dedifferentiation (also known as high-grade transformation) and aggressive clinical behavior. To date, the dedifferentiated component in all molecularly confirmed cases of secretory carcinoma has taken the form of a high-grade carcinoma. Here we present a case of an ETV6-NTRK3 fusion-positive secretory carcinoma of the breast with sarcomatous dedifferentiation. The sarcomatous component showed an infantile or adult fibrosarcoma-like morphology including a herringbone fascicular pattern and a hemangiopericytic vascular pattern. By immunohistochemistry, the sarcomatous component showed focal CD34 immunoreactivity and loss of all of the markers expressed in the conventional secretory carcinoma component, including SOX10, S100, GATA-3, AE1/AE3 and E-cadherin. Fluorescence in situ hybridization analysis revealed that the sarcomatous component retained the ETV6-NTRK3 fusion, but also acquired homozygous deletion of CDKN2A. The tumor followed an aggressive clinical course and the patient eventually succumbed to her disease 14 months after diagnosis. The histomorphologic and molecular genetic features of this tumor are discussed, including its ability to mimic kinase-rearranged infantile or adult fibrosarcomas at extramammary sites and the theragnostic importance of its distinction from conventional metaplastic spindle cell carcinomas in the breast.

Adenoid cystic carcinoma with dedifferentiation/expansion of the luminal cell component and preserved biphasic morphology - Early high-grade transformation

We present two patients (29 and 67 years) with histomorphologic and immunohistochemical evidence of early high-grade transformation of adenoid cystic carcinoma in the nasal cavity and floor of mouth, respectively. The component of early high-grade transformation was characterized by 1) selective expansion of the luminal (CK7+, c-kit+, p63-) cell component with severe cytologic atypia and significantly increased Ki-67 proliferation index, and 2) retained albeit attenuated abluminal (CK7-, c-kit-, p63+) cells, surrounding nests of high-grade luminal cells.

Adenoid Cystic Carcinoma with Transformation to High Grade Carcinomatous and Sarcomatoid Components: A Rare Case Report with Review of Literature

Adenoid cystic carcinoma (AdCC) comprises of less than 1% of all head and neck cancers and less than 10% of all salivary gland neoplasms. Dedifferentiation/high-grade transformation (HGT) in AdCC is a rare but well known phenomenon which is associated with aggressive clinical behaviour and poor prognosis. We herein report the clinical, cytologic, histologic and immunohistochemical findings of a left submandibular gland AdCC with transformation to high grade carcinomatous and probable dedifferentiation to sarcomatoid component, occurring in a 64 year old male patient. To the author's best knowledge, this is the first case report of such dual transformation occurring in adenoid cystic carcinoma.

Adenoid cystic carcinoma with high-grade transformation forming spindle cell component of the submandibular gland

Adenoid cystic carcinoma (AdCC) with high-grade transformation (AdCC-HGT) is rare, and AdCC-HGT with spindle cell component is particularly rare. The patient was a 65-year-old man with a 5 cm sized swelling of the right submandibular gland. Submandibular sialoadenectomy was performed. Histopathological findings mainly showed conventional AdCC, and minorly showed two other components: (1) the pleomorphic component, a proliferation of atypical pleomorphic epithelial cells forming solid or small clusters and accompanied by necrosis; (2) the spindle cell component, containing atypical spindle cells invading the stroma. Postoperative chemoradiotherapy was performed. Multiple right lung nodular lesions were found on the contrast-enhanced chest CT one month after the surgery. Thoracoscopic pulmonary resection was performed. The lung tumors exhibited a proliferation of atypical spindle cells, accompanied by necrosis. We considered that the spindle cell component of the AdCC-HGT of the submandibular gland developed lung metastases. The patient died seven months after submandibular sialoadenectomy due to respiratory failure. Although rare, our case highlights the importance of recognising spindle cell components in conventional AdCC; even if the area is small, these high-grade transformation areas can metastasise and become prognostic factors.