Invasive micropapillary carcinoma has been recently recognized as a rare but distinctive variant of carcinoma in various anatomic sites, including breast, urinary bladder, lung, and major salivary glands. Morphologically, it is characterized by small tight clusters of neoplastic cells floating in clear spaces resembling lymphatic channels. Most often this growth pattern is mixed with a variable component of conventional carcinoma or other variants. In addition to a unique morphology, tumors with invasive micropapillary growth share a high propensity for lymphovascular invasion and lymph node metastases. Patients have typically high-stage disease at presentation and a poor clinical outcome compared with that of patients with conventional carcinoma arising in the same organ site. In this article the author reviews the available literature on tumors displaying a micropapillary component.
"Studies from other organs such as the breast that categorized the tumors into groups according to the percentage of micropapillary component have found no correlation between the proportion of micropapillary carcinoma and the percentage of lymph node metastasis or lymphovascular invasion; tumors with any amount of micropapillary pattern showed a higher propensity for lymphovascular invasion and lymph node metastasis compared with other types of carcinoma  . Although micropapillary component may not be an independent predictor of an aggressive clinical behavior, the characteristic hobnail pattern with variable degrees of micropapillary features appears to be associated with a poor outcome . Some other variants of PTC such as classical and diffuse sclerosing in rare cases could show a micropapillary pattern of growth (personal observation). "
[Show abstract][Hide abstract] ABSTRACT: Recent reports indicate that papillary thyroid carcinoma with hobnail features, also designated as micropapillary variant of papillary thyroid carcinoma, is a rare but very aggressive variant of papillary thyroid carcinoma. We examined the histopathologic and immunohistochemical features of 24 cases of papillary thyroid carcinoma with hobnail/micropapillary component to determine the prognostic significance of the amount of hobnail/micropapillary features in these tumors. The patients included 18 women and 6 men. Ages ranged from 28 to 78 years (mean, 57 years). Tumor size ranged from 1 to 5.8 cm (mean, 3 cm). The average follow-up time was 106 months (range, 4-274 months). Twelve cases (50%) of papillary thyroid carcinoma showed more than 30% hobnail/micropapillary features, and all but 3 cases were associated with an aggressive behavior. During the follow-up, 6 of these patients died of disease after a mean of 44.8 months, and 3 patients remained alive with extensive disease after a mean follow-up of 32.3 months. Metastases to lymph nodes or distant organs showed a hobnail pattern of growth similar to the primary tumor. The remaining 3 patients with prominent hobnail/micropapillary features were alive with no evidence of disease after a mean follow-up of 125.3 months. The other 12 papillary thyroid carcinoma cases (50%) showed less than 30% hobnail/micropapillary features. Nine of these patients were alive without disease after a mean of 162 months, and 1 patient died of sepsis, which was not related to thyroid tumor after 155 months. Two patients in this group died of disease after 21 and 163 months, respectively. These findings confirm earlier observations that papillary thyroid carcinoma with hobnail/micropapillary features is an aggressive variant of papillary thyroid carcinoma. Tumors with more than 30% hobnail/micropapillary features were often very aggressive, although 2 patients with tumors with 10% hobnail/micropapillary features also had poor outcomes.
Human pathology 10/2012; 44(3). DOI:10.1016/j.humpath.2012.06.003 · 2.77 Impact Factor
"Carcinomas with micropapillary components have been reported at several anatomical sites, including the breast, urinary bladder, ovary, major salivary glands, and recently the lungs (4). The micropapillary component is being increasingly recognized as a prognostic predictor for aggressive behavior with a tendency to metastasize to the lymph nodes and other organs (5, 6). "
[Show abstract][Hide abstract] ABSTRACT: A 47-year-old Korean woman with right middle lobe lung adenocarcinoma, malignant pleural effusion, and multiple lymph node and bone metastases, after three months of lung cancer diagnosis, presented with a palpable right breast mass. Images of the right breast demonstrated architectural distortion that strongly suggested primary breast cancer. Breast biopsy revealed metastatic lung cancer with a negative result for estrogen receptor (ER), progesterone receptor (PR) and mammaglobin, and a positive result for thyroid transcription factor-1 (TTF-1). We present a case of breast metastasis from a case of lung cancer with an extensive micropapillary component, which was initially misinterpreted as a primary breast cancer due to unusual image findings with architectural distortion.
Korean journal of radiology: official journal of the Korean Radiological Society 03/2012; 13(2):249-53. DOI:10.3348/kjr.2012.13.2.249 · 1.57 Impact Factor
"With that, tumor cells facing the stroma acquire apical secretory properties evidenced by ultrastructural examination and immunostaining for MUC1, a surface glycoprotein present on the apical/luminal surface. This unusual interface might lead to the detachment of tumor cells from the stroma, facilitating stromal invasion . "
[Show abstract][Hide abstract] ABSTRACT: Micropapillary carcinoma (MPC) of urinary tract is an uncommon variant of urothelial carcinoma with significant diagnostic and prognostic implications. Though MPC shows characteristic microscopic features, there exists interobserver variability and also it needs to be differentiated from the metastasis from other organs. The prognosis is generally poor, depending on the proportion of the micropapillary component in some reports. Early cystectomy in cases with only lamina propria invasion may be indicated according to recent studies. This review outlines the general features of this entity and briefly comments on the controversies and the recent development.
Advances in Urology 10/2011; 2011:217153. DOI:10.1155/2011/217153
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.